diff --git a/.github/workflows/version.yml b/.github/workflows/version.yml
index eaf4d085c6946..fdf42a9a2731e 100644
--- a/.github/workflows/version.yml
+++ b/.github/workflows/version.yml
@@ -30,7 +30,11 @@ jobs:
           CURRENT_VERSION_ARRAY[2]=$((CURRENT_VERSION_ARRAY[2]+1))
           NEXT_VERSION=$(IFS=. ; echo "${CURRENT_VERSION_ARRAY[*]:0:3}")
           NEXT_VERSION_UNDERSCORE=$(IFS=_ ; echo "V_${CURRENT_VERSION_ARRAY[*]:0:3}")
-          NEXT_VERSION_ID=$(IFS=0 ; echo "${CURRENT_VERSION_ARRAY[*]:0:3}99")
+          if [[ ${#CURRENT_VERSION_ARRAY[2]} -gt 1 ]]; then
+            NEXT_VERSION_ID="${CURRENT_VERSION_ARRAY[0]:0:3}0${CURRENT_VERSION_ARRAY[1]:0:3}${CURRENT_VERSION_ARRAY[2]:0:3}99"
+          else
+            NEXT_VERSION_ID=$(IFS=0 ; echo "${CURRENT_VERSION_ARRAY[*]:0:3}99")
+          fi
           echo "TAG=$TAG" >> $GITHUB_ENV
           echo "BASE=$BASE" >> $GITHUB_ENV
           echo "BASE_X=$BASE_X" >> $GITHUB_ENV
diff --git a/CHANGELOG.md b/CHANGELOG.md
index b183dddc3c489..0ad8838bd8c91 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,7 +14,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 ### Dependencies
 - Bump `log4j-core` from 2.18.0 to 2.19.0
 - Bump `forbiddenapis` from 3.3 to 3.4
-- Bump `avro` from 1.11.0 to 1.11.1
+- Bump `avro` from 1.11.1 to 1.11.2
 - Bump `woodstox-core` from 6.3.0 to 6.3.1
 - Bump `xmlbeans` from 5.1.0 to 5.1.1 ([#4354](https://github.com/opensearch-project/OpenSearch/pull/4354))
 - Bump `reactor-netty-core` from 1.0.19 to 1.0.22 ([#4447](https://github.com/opensearch-project/OpenSearch/pull/4447))
@@ -51,6 +51,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Improve summary error message for invalid setting updates ([#4792](https://github.com/opensearch-project/OpenSearch/pull/4792))
 - Pass localNode info to all plugins on node start ([#7919](https://github.com/opensearch-project/OpenSearch/pull/7919))
 - Improved performance of parsing floating point numbers ([#7909](https://github.com/opensearch-project/OpenSearch/pull/7909))
+- Move span actions to Scope ([#8411](https://github.com/opensearch-project/OpenSearch/pull/8411))
 
 ### Deprecated
 
@@ -76,6 +77,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Support OpenSSL Provider with default Netty allocator ([#5460](https://github.com/opensearch-project/OpenSearch/pull/5460))
 - Replaces ZipInputStream with ZipFile to fix Zip Slip vulnerability ([#7230](https://github.com/opensearch-project/OpenSearch/pull/7230))
 - Add missing validation/parsing of SearchBackpressureMode of SearchBackpressureSettings ([#7541](https://github.com/opensearch-project/OpenSearch/pull/7541))
+- Adds log4j configuration for telemetry LogSpanExporter ([#8393](https://github.com/opensearch-project/OpenSearch/pull/8393))
 
 ### Security
 
@@ -95,6 +97,11 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Start replication checkpointTimers on primary before segments upload to remote store. ([#8221]()https://github.com/opensearch-project/OpenSearch/pull/8221)
 - Add distributed tracing framework ([#7543](https://github.com/opensearch-project/OpenSearch/issues/7543))
 - Enable Point based optimization for custom comparators ([#8168](https://github.com/opensearch-project/OpenSearch/pull/8168))
+- [Extensions] Support extension additional settings with extension REST initialization ([#8414](https://github.com/opensearch-project/OpenSearch/pull/8414))
+- Adds mock implementation for TelemetryPlugin ([#7545](https://github.com/opensearch-project/OpenSearch/issues/7545))
+- Support transport action names when registering NamedRoutes ([#7957](https://github.com/opensearch-project/OpenSearch/pull/7957))
+- Create concept of persistent ThreadContext headers that are unstashable ([#8291]()https://github.com/opensearch-project/OpenSearch/pull/8291)
+- Enable Partial Flat Object ([#7997](https://github.com/opensearch-project/OpenSearch/pull/7997))
 
 ### Dependencies
 - Bump `com.azure:azure-storage-common` from 12.21.0 to 12.21.1 (#7566, #7814)
@@ -127,6 +134,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - [Upgrade] Lucene 9.7.0 release (#8272)
 - Bump `org.jboss.resteasy:resteasy-jackson2-provider` from 3.0.26.Final to 6.2.4.Final in /qa/wildfly ([#8209](https://github.com/opensearch-project/OpenSearch/pull/8209))
 - Bump `com.google.api-client:google-api-client` from 1.34.0 to 2.2.0 ([#8276](https://github.com/opensearch-project/OpenSearch/pull/8276))
+- Update Apache HttpCore/ HttpClient and Apache HttpCore5 / HttpClient5 dependencies ([#8434](https://github.com/opensearch-project/OpenSearch/pull/8434))
+- Bump `org.apache.maven:maven-model` from 3.9.2 to 3.9.3 (#8403)
+- Bump `io.projectreactor.netty:reactor-netty` and `io.projectreactor.netty:reactor-netty-core` from 1.1.7 to 1.1.8 (#8405)
 
 ### Changed
 - Replace jboss-annotations-api_1.2_spec with jakarta.annotation-api ([#7836](https://github.com/opensearch-project/OpenSearch/pull/7836))
@@ -144,6 +154,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Add self-organizing hash table to improve the performance of bucket aggregations ([#7652](https://github.com/opensearch-project/OpenSearch/pull/7652))
 - Check UTF16 string size before converting to String to avoid OOME ([#7963](https://github.com/opensearch-project/OpenSearch/pull/7963))
 - Move ZSTD compression codecs out of the sandbox ([#7908](https://github.com/opensearch-project/OpenSearch/pull/7908))
+- Update ZSTD default compression level ([#8471](https://github.com/opensearch-project/OpenSearch/pull/8471))
+- [Search Pipelines] Pass pipeline creation context to processor factories ([#8164](https://github.com/opensearch-project/OpenSearch/pull/8164))
 
 
 ### Deprecated
diff --git a/benchmarks/build.gradle b/benchmarks/build.gradle
index 4a7825e9ba35b..02aa9319cc583 100644
--- a/benchmarks/build.gradle
+++ b/benchmarks/build.gradle
@@ -32,10 +32,16 @@ import org.opensearch.gradle.info.BuildParams
 
 apply plugin: 'opensearch.build'
 apply plugin: 'application'
-mainClassName = 'org.openjdk.jmh.Main'
 
 assemble.enabled = false
-archivesBaseName = 'opensearch-benchmarks'
+
+application {
+  mainClass = 'org.openjdk.jmh.Main'
+}
+
+base {
+  archivesBaseName = 'opensearch-benchmarks'
+}
 
 test.enabled = false
 
diff --git a/build.gradle b/build.gradle
index eec01e840149e..ca4c6c3635d57 100644
--- a/build.gradle
+++ b/build.gradle
@@ -327,7 +327,7 @@ allprojects {
       javadoc.options.addStringOption('Xwerror', '-quiet')
     }
     javadoc.options.tags = ["opensearch.internal", "opensearch.api", "opensearch.experimental"]
-    javadoc.options.addStringOption("-release", targetCompatibility.majorVersion)
+    javadoc.options.addStringOption("-release", java.targetCompatibility.majorVersion)
   }
 
   // support for reproducible builds
@@ -375,7 +375,7 @@ allprojects {
         } else {
           // Link to non-shadowed dependant projects
           project.javadoc.dependsOn "${upstreamProject.path}:javadoc"
-          String externalLinkName = upstreamProject.archivesBaseName
+          String externalLinkName = upstreamProject.base.archivesBaseName
           String artifactPath = dep.group.replaceAll('\\.', '/') + '/' + externalLinkName.replaceAll('\\.', '/') + '/' + dep.version
           String projectRelativePath = project.relativePath(upstreamProject.buildDir)
           project.javadoc.options.linksOffline artifactsHost + "/javadoc/" + artifactPath, "${projectRelativePath}/docs/javadoc/"
@@ -452,7 +452,7 @@ gradle.projectsEvaluated {
       testReportAggregation it
     }
     subprojects.findAll { it.pluginManager.hasPlugin('jacoco') }.forEach {
-     jacocoAggregation it
+      jacocoAggregation it
     }
   }
 }
diff --git a/buildSrc/build.gradle b/buildSrc/build.gradle
index 35f3fb87560e7..feb8da7c20984 100644
--- a/buildSrc/build.gradle
+++ b/buildSrc/build.gradle
@@ -34,7 +34,6 @@ import org.gradle.util.GradleVersion
 plugins {
   id 'java-gradle-plugin'
   id 'groovy'
-  id 'java-test-fixtures'
 }
 
 group = 'org.opensearch.gradle'
@@ -79,9 +78,17 @@ if (JavaVersion.current() < JavaVersion.VERSION_11) {
 }
 
 sourceSets {
+  test {
+    java {
+      srcDirs += ['src/testFixtures/java']
+    }
+  }
   integTest {
     compileClasspath += sourceSets["main"].output + configurations["testRuntimeClasspath"]
     runtimeClasspath += output + compileClasspath
+    java {
+      srcDirs += ['src/testFixtures/java']
+    }
   }
 }
 
@@ -111,23 +118,23 @@ dependencies {
   api 'org.apache.rat:apache-rat:0.15'
   api 'commons-io:commons-io:2.13.0'
   api "net.java.dev.jna:jna:5.13.0"
-  api 'gradle.plugin.com.github.johnrengelman:shadow:8.0.0'
+  api 'com.github.johnrengelman:shadow:8.1.1'
   api 'org.jdom:jdom2:2.0.6.1'
   api "org.jetbrains.kotlin:kotlin-stdlib-jdk8:${props.getProperty('kotlin')}"
   api 'de.thetaphi:forbiddenapis:3.5.1'
   api 'com.avast.gradle:gradle-docker-compose-plugin:0.16.12'
   api "org.yaml:snakeyaml:${props.getProperty('snakeyaml')}"
-  api 'org.apache.maven:maven-model:3.9.2'
+  api 'org.apache.maven:maven-model:3.9.3'
   api 'com.networknt:json-schema-validator:1.0.85'
   api 'org.jruby.jcodings:jcodings:1.0.58'
   api 'org.jruby.joni:joni:2.2.1'
   api "com.fasterxml.jackson.core:jackson-databind:${props.getProperty('jackson_databind')}"
   api "org.ajoberstar.grgit:grgit-core:5.2.0"
 
-  testFixturesApi "junit:junit:${props.getProperty('junit')}"
-  testFixturesApi "com.carrotsearch.randomizedtesting:randomizedtesting-runner:${props.getProperty('randomizedrunner')}"
-  testFixturesApi gradleApi()
-  testFixturesApi gradleTestKit()
+  testImplementation "junit:junit:${props.getProperty('junit')}"
+  testImplementation "com.carrotsearch.randomizedtesting:randomizedtesting-runner:${props.getProperty('randomizedrunner')}"
+  testRuntimeOnly gradleApi()
+  testRuntimeOnly gradleTestKit()
   testImplementation 'com.github.tomakehurst:wiremock-jre8-standalone:2.35.0'
   testImplementation "org.mockito:mockito-core:${props.getProperty('mockito')}"
   integTestImplementation('org.spockframework:spock-core:2.3-groovy-3.0') {
@@ -164,8 +171,10 @@ if (project != rootProject) {
   apply plugin: 'opensearch.publish'
 
   allprojects {
-    targetCompatibility = JavaVersion.VERSION_11
-    sourceCompatibility = JavaVersion.VERSION_11
+    java {
+        targetCompatibility = JavaVersion.VERSION_11
+        sourceCompatibility = JavaVersion.VERSION_11
+    }
   }
 
   // groovydoc succeeds, but has some weird internal exception...
@@ -174,7 +183,7 @@ if (project != rootProject) {
   // build-tools is not ready for primetime with these...
   tasks.named("dependencyLicenses").configure { it.enabled = false }
   dependenciesInfo.enabled = false
-  disableTasks('forbiddenApisMain', 'forbiddenApisTest', 'forbiddenApisIntegTest', 'forbiddenApisTestFixtures')
+  disableTasks('forbiddenApisMain', 'forbiddenApisTest', 'forbiddenApisIntegTest')
   jarHell.enabled = false
   thirdPartyAudit.enabled = false
   if (org.opensearch.gradle.info.BuildParams.inFipsJvm) {
@@ -241,12 +250,6 @@ if (project != rootProject) {
     }
   }
 
-  // disable fail-on-warnings for this specific task which trips Java 11 bug
-  // https://bugs.openjdk.java.net/browse/JDK-8209058
-  tasks.named("compileTestFixturesJava").configure {
-    options.compilerArgs -= '-Werror'
-  }
-
   tasks.register("integTest", Test) {
     inputs.dir(file("src/testKit")).withPropertyName("testkit dir").withPathSensitivity(PathSensitivity.RELATIVE)
     systemProperty 'test.version_under_test', version
diff --git a/buildSrc/reaper/build.gradle b/buildSrc/reaper/build.gradle
index 4ccbec894e30e..58d06b02e9f4b 100644
--- a/buildSrc/reaper/build.gradle
+++ b/buildSrc/reaper/build.gradle
@@ -11,8 +11,10 @@
 
 apply plugin: 'java'
 
-targetCompatibility = JavaVersion.VERSION_11
-sourceCompatibility = JavaVersion.VERSION_11
+java {
+  targetCompatibility = JavaVersion.VERSION_11
+  sourceCompatibility = JavaVersion.VERSION_11
+}
 
 jar {
   archiveFileName = "${project.name}.jar"
diff --git a/buildSrc/src/main/groovy/org/opensearch/gradle/plugin/PluginBuildPlugin.groovy b/buildSrc/src/main/groovy/org/opensearch/gradle/plugin/PluginBuildPlugin.groovy
index 2428d9e2fa4fa..556763333d279 100644
--- a/buildSrc/src/main/groovy/org/opensearch/gradle/plugin/PluginBuildPlugin.groovy
+++ b/buildSrc/src/main/groovy/org/opensearch/gradle/plugin/PluginBuildPlugin.groovy
@@ -44,6 +44,8 @@ import org.gradle.api.Plugin
 import org.gradle.api.Project
 import org.gradle.api.Task
 import org.gradle.api.plugins.BasePlugin
+import org.gradle.api.plugins.BasePluginExtension
+import org.gradle.api.plugins.JavaPluginExtension
 import org.gradle.api.publish.maven.MavenPublication
 import org.gradle.api.publish.maven.plugins.MavenPublishPlugin
 import org.gradle.api.publish.maven.tasks.GenerateMavenPom
@@ -85,7 +87,9 @@ class PluginBuildPlugin implements Plugin<Project> {
             PluginPropertiesExtension extension1 = project.getExtensions().getByType(PluginPropertiesExtension.class)
             configurePublishing(project, extension1)
             String name = extension1.name
-            project.archivesBaseName = name
+
+            BasePluginExtension base = project.getExtensions().findByType(BasePluginExtension.class)
+            base.archivesBaseName = name
             project.description = extension1.description
 
             if (extension1.name == null) {
@@ -98,12 +102,13 @@ class PluginBuildPlugin implements Plugin<Project> {
                 throw new InvalidUserDataException('classname is a required setting for opensearchplugin')
             }
 
+            JavaPluginExtension java = project.getExtensions().findByType(JavaPluginExtension.class)
             Map<String, String> properties = [
                     'name'                : extension1.name,
                     'description'         : extension1.description,
                     'version'             : extension1.version,
                     'opensearchVersion'   : Version.fromString(VersionProperties.getOpenSearch()).toString(),
-                    'javaVersion'         : project.targetCompatibility as String,
+                    'javaVersion'         : java.targetCompatibility as String,
                     'classname'           : extension1.classname,
                     'customFolderName'    : extension1.customFolderName,
                     'extendedPlugins'     : extension1.extendedPlugins.join(','),
@@ -156,8 +161,9 @@ class PluginBuildPlugin implements Plugin<Project> {
             }
             // always configure publishing for client jars
             project.publishing.publications.nebula(MavenPublication).artifactId(extension.name + "-client")
+            final BasePluginExtension base = project.getExtensions().findByType(BasePluginExtension.class)
             project.tasks.withType(GenerateMavenPom.class).configureEach { GenerateMavenPom generatePOMTask ->
-                generatePOMTask.destination = "${project.buildDir}/distributions/${project.archivesBaseName}-client-${project.versions.opensearch}.pom"
+                generatePOMTask.destination = "${project.buildDir}/distributions/${base.archivesBaseName}-client-${project.versions.opensearch}.pom"
             }
         } else {
             if (project.plugins.hasPlugin(MavenPublishPlugin)) {
diff --git a/buildSrc/src/main/java/org/opensearch/gradle/PublishPlugin.java b/buildSrc/src/main/java/org/opensearch/gradle/PublishPlugin.java
index 1015a2dfb7d72..97e923c366598 100644
--- a/buildSrc/src/main/java/org/opensearch/gradle/PublishPlugin.java
+++ b/buildSrc/src/main/java/org/opensearch/gradle/PublishPlugin.java
@@ -46,7 +46,7 @@
 import org.gradle.api.XmlProvider;
 import org.gradle.api.artifacts.ProjectDependency;
 import org.gradle.api.plugins.BasePlugin;
-import org.gradle.api.plugins.BasePluginConvention;
+import org.gradle.api.plugins.BasePluginExtension;
 import org.gradle.api.plugins.JavaPlugin;
 import org.gradle.api.publish.PublishingExtension;
 import org.gradle.api.publish.maven.MavenPublication;
@@ -77,7 +77,7 @@ public void apply(Project project) {
     }
 
     private static String getArchivesBaseName(Project project) {
-        return project.getConvention().getPlugin(BasePluginConvention.class).getArchivesBaseName();
+        return project.getExtensions().getByType(BasePluginExtension.class).getArchivesBaseName();
     }
 
     /**Configuration generation of maven poms. */
diff --git a/buildSrc/src/main/java/org/opensearch/gradle/precommit/ForbiddenPatternsTask.java b/buildSrc/src/main/java/org/opensearch/gradle/precommit/ForbiddenPatternsTask.java
index 754743b9b784c..6ef1e77f5138f 100644
--- a/buildSrc/src/main/java/org/opensearch/gradle/precommit/ForbiddenPatternsTask.java
+++ b/buildSrc/src/main/java/org/opensearch/gradle/precommit/ForbiddenPatternsTask.java
@@ -36,7 +36,7 @@
 import org.gradle.api.InvalidUserDataException;
 import org.gradle.api.file.FileCollection;
 import org.gradle.api.file.FileTree;
-import org.gradle.api.plugins.JavaPluginConvention;
+import org.gradle.api.plugins.JavaPluginExtension;
 import org.gradle.api.tasks.IgnoreEmptyDirectories;
 import org.gradle.api.tasks.Input;
 import org.gradle.api.tasks.InputFiles;
@@ -106,8 +106,8 @@ public ForbiddenPatternsTask() {
     @IgnoreEmptyDirectories
     @PathSensitive(PathSensitivity.RELATIVE)
     public FileCollection getFiles() {
-        return getProject().getConvention()
-            .getPlugin(JavaPluginConvention.class)
+        return getProject().getExtensions()
+            .getByType(JavaPluginExtension.class)
             .getSourceSets()
             .stream()
             .map(sourceSet -> sourceSet.getAllSource().matching(filesFilter))
diff --git a/buildSrc/src/main/java/org/opensearch/gradle/precommit/LoggerUsageTask.java b/buildSrc/src/main/java/org/opensearch/gradle/precommit/LoggerUsageTask.java
index ff9f6619d64e6..db215fb65ef95 100644
--- a/buildSrc/src/main/java/org/opensearch/gradle/precommit/LoggerUsageTask.java
+++ b/buildSrc/src/main/java/org/opensearch/gradle/precommit/LoggerUsageTask.java
@@ -34,7 +34,7 @@
 
 import org.opensearch.gradle.LoggedExec;
 import org.gradle.api.file.FileCollection;
-import org.gradle.api.plugins.JavaPluginConvention;
+import org.gradle.api.plugins.JavaPluginExtension;
 import org.gradle.api.tasks.CacheableTask;
 import org.gradle.api.tasks.Classpath;
 import org.gradle.api.tasks.IgnoreEmptyDirectories;
@@ -82,8 +82,8 @@ public void setClasspath(FileCollection classpath) {
     @SkipWhenEmpty
     @IgnoreEmptyDirectories
     public FileCollection getClassDirectories() {
-        return getProject().getConvention()
-            .getPlugin(JavaPluginConvention.class)
+        return getProject().getExtensions()
+            .getByType(JavaPluginExtension.class)
             .getSourceSets()
             .stream()
             // Don't pick up all source sets like the java9 ones as logger-check doesn't support the class format
diff --git a/buildSrc/src/main/java/org/opensearch/gradle/test/rest/CopyRestApiTask.java b/buildSrc/src/main/java/org/opensearch/gradle/test/rest/CopyRestApiTask.java
index 1468c4cb1b537..0275664276877 100644
--- a/buildSrc/src/main/java/org/opensearch/gradle/test/rest/CopyRestApiTask.java
+++ b/buildSrc/src/main/java/org/opensearch/gradle/test/rest/CopyRestApiTask.java
@@ -41,7 +41,7 @@
 import org.gradle.api.file.ConfigurableFileCollection;
 import org.gradle.api.file.FileSystemOperations;
 import org.gradle.api.file.FileTree;
-import org.gradle.api.plugins.JavaPluginConvention;
+import org.gradle.api.plugins.JavaPluginExtension;
 import org.gradle.api.provider.ListProperty;
 import org.gradle.api.tasks.IgnoreEmptyDirectories;
 import org.gradle.api.tasks.Input;
@@ -240,7 +240,7 @@ private File getTestOutputResourceDir() {
 
     private Optional<SourceSet> getSourceSet() {
         Project project = getProject();
-        return project.getConvention().findPlugin(JavaPluginConvention.class) == null
+        return project.getExtensions().findByType(JavaPluginExtension.class) == null
             ? Optional.empty()
             : Optional.ofNullable(GradleUtils.getJavaSourceSets(project).findByName(getSourceSetName()));
     }
diff --git a/buildSrc/src/main/java/org/opensearch/gradle/test/rest/CopyRestTestsTask.java b/buildSrc/src/main/java/org/opensearch/gradle/test/rest/CopyRestTestsTask.java
index dd94d040cb9d8..ebd6c49fd6157 100644
--- a/buildSrc/src/main/java/org/opensearch/gradle/test/rest/CopyRestTestsTask.java
+++ b/buildSrc/src/main/java/org/opensearch/gradle/test/rest/CopyRestTestsTask.java
@@ -41,7 +41,7 @@
 import org.gradle.api.file.ConfigurableFileCollection;
 import org.gradle.api.file.FileSystemOperations;
 import org.gradle.api.file.FileTree;
-import org.gradle.api.plugins.JavaPluginConvention;
+import org.gradle.api.plugins.JavaPluginExtension;
 import org.gradle.api.provider.ListProperty;
 import org.gradle.api.tasks.IgnoreEmptyDirectories;
 import org.gradle.api.tasks.Input;
@@ -178,7 +178,7 @@ void copy() {
 
     private Optional<SourceSet> getSourceSet() {
         Project project = getProject();
-        return project.getConvention().findPlugin(JavaPluginConvention.class) == null
+        return project.getExtensions().findByType(JavaPluginExtension.class) == null
             ? Optional.empty()
             : Optional.ofNullable(GradleUtils.getJavaSourceSets(project).findByName(getSourceSetName()));
     }
diff --git a/buildSrc/src/main/java/org/opensearch/gradle/util/GradleUtils.java b/buildSrc/src/main/java/org/opensearch/gradle/util/GradleUtils.java
index 054f01788d126..031fee2d1127f 100644
--- a/buildSrc/src/main/java/org/opensearch/gradle/util/GradleUtils.java
+++ b/buildSrc/src/main/java/org/opensearch/gradle/util/GradleUtils.java
@@ -40,7 +40,7 @@
 import org.gradle.api.artifacts.Configuration;
 import org.gradle.api.artifacts.Dependency;
 import org.gradle.api.plugins.JavaBasePlugin;
-import org.gradle.api.plugins.JavaPluginConvention;
+import org.gradle.api.plugins.JavaPluginExtension;
 import org.gradle.api.provider.Provider;
 import org.gradle.api.services.BuildService;
 import org.gradle.api.services.BuildServiceRegistration;
@@ -68,7 +68,7 @@ public static <T> Action<T> noop() {
     }
 
     public static SourceSetContainer getJavaSourceSets(Project project) {
-        return project.getConvention().getPlugin(JavaPluginConvention.class).getSourceSets();
+        return project.getExtensions().getByType(JavaPluginExtension.class).getSourceSets();
     }
 
     public static <T extends Task> TaskProvider<T> maybeRegister(TaskContainer tasks, String name, Class<T> clazz, Action<T> action) {
diff --git a/buildSrc/src/main/java/org/opensearch/gradle/util/Util.java b/buildSrc/src/main/java/org/opensearch/gradle/util/Util.java
index 71b1e5040340d..a4d2c59cf8cad 100644
--- a/buildSrc/src/main/java/org/opensearch/gradle/util/Util.java
+++ b/buildSrc/src/main/java/org/opensearch/gradle/util/Util.java
@@ -37,7 +37,7 @@
 import org.gradle.api.GradleException;
 import org.gradle.api.Project;
 import org.gradle.api.file.FileTree;
-import org.gradle.api.plugins.JavaPluginConvention;
+import org.gradle.api.plugins.JavaPluginExtension;
 import org.gradle.api.tasks.SourceSet;
 import org.gradle.api.tasks.util.PatternFilterable;
 
@@ -149,7 +149,7 @@ public static FileTree getJavaTestAndMainSourceResources(Project project, Action
      * @return An Optional that contains the Java test SourceSet if it exists.
      */
     public static Optional<SourceSet> getJavaTestSourceSet(Project project) {
-        return project.getConvention().findPlugin(JavaPluginConvention.class) == null
+        return project.getExtensions().findByType(JavaPluginExtension.class) == null
             ? Optional.empty()
             : Optional.ofNullable(GradleUtils.getJavaSourceSets(project).findByName(SourceSet.TEST_SOURCE_SET_NAME));
     }
@@ -159,7 +159,7 @@ public static Optional<SourceSet> getJavaTestSourceSet(Project project) {
      * @return An Optional that contains the Java main SourceSet if it exists.
      */
     public static Optional<SourceSet> getJavaMainSourceSet(Project project) {
-        return project.getConvention().findPlugin(JavaPluginConvention.class) == null
+        return project.getExtensions().findByType(JavaPluginExtension.class) == null
             ? Optional.empty()
             : Optional.ofNullable(GradleUtils.getJavaSourceSets(project).findByName(SourceSet.MAIN_SOURCE_SET_NAME));
     }
diff --git a/buildSrc/version.properties b/buildSrc/version.properties
index f9eac9516cb18..408b03e60cc5d 100644
--- a/buildSrc/version.properties
+++ b/buildSrc/version.properties
@@ -33,10 +33,10 @@ netty             = 4.1.94.Final
 joda              = 2.12.2
 
 # client dependencies
-httpclient5       = 5.1.4
-httpcore5         = 5.1.5
-httpclient        = 4.5.13
-httpcore          = 4.4.15
+httpclient5       = 5.2.1
+httpcore5         = 5.2.2
+httpclient        = 4.5.14
+httpcore          = 4.4.16
 httpasyncclient   = 4.1.5
 commonslogging    = 1.2
 commonscodec      = 1.15
diff --git a/client/benchmark/build.gradle b/client/benchmark/build.gradle
index 4aa4d7171e366..6fd5262f0ab4f 100644
--- a/client/benchmark/build.gradle
+++ b/client/benchmark/build.gradle
@@ -31,13 +31,17 @@
 apply plugin: 'opensearch.build'
 apply plugin: 'application'
 
-group = 'org.opensearch.client'
+base {
+  group = 'org.opensearch.client'
+  archivesBaseName = 'client-benchmarks'
+}
 
 // Not published so no need to assemble
 assemble.enabled = true
 
-archivesBaseName = 'client-benchmarks'
-mainClassName = 'org.opensearch.client.benchmark.BenchmarkMain'
+application {
+  mainClass = 'org.opensearch.client.benchmark.BenchmarkMain'
+}
 
 // never try to invoke tests on the benchmark project - there aren't any
 test.enabled = false
diff --git a/client/rest-high-level/build.gradle b/client/rest-high-level/build.gradle
index 43758560b2a15..7daf4761b9310 100644
--- a/client/rest-high-level/build.gradle
+++ b/client/rest-high-level/build.gradle
@@ -37,8 +37,10 @@ apply plugin: 'opensearch.rest-test'
 apply plugin: 'opensearch.publish'
 apply plugin: 'opensearch.rest-resources'
 
-group = 'org.opensearch.client'
-archivesBaseName = 'opensearch-rest-high-level-client'
+base {
+  group = 'org.opensearch.client'
+  archivesBaseName = 'opensearch-rest-high-level-client'
+}
 
 restResources {
   //we need to copy the yaml spec so we can check naming (see RestHighlevelClientTests#testApiNamingConventions)
diff --git a/client/rest/build.gradle b/client/rest/build.gradle
index 9ea7ad4ddb964..2c437c909fb03 100644
--- a/client/rest/build.gradle
+++ b/client/rest/build.gradle
@@ -33,11 +33,15 @@ import de.thetaphi.forbiddenapis.gradle.CheckForbiddenApis
 apply plugin: 'opensearch.build'
 apply plugin: 'opensearch.publish'
 
-targetCompatibility = JavaVersion.VERSION_11
-sourceCompatibility = JavaVersion.VERSION_11
+java {
+  targetCompatibility = JavaVersion.VERSION_11
+  sourceCompatibility = JavaVersion.VERSION_11
+}
 
-group = 'org.opensearch.client'
-archivesBaseName = 'opensearch-rest-client'
+base {
+  group = 'org.opensearch.client'
+  archivesBaseName = 'opensearch-rest-client'
+}
 
 dependencies {
   api "org.apache.httpcomponents.client5:httpclient5:${versions.httpclient5}"
diff --git a/client/rest/licenses/httpclient5-5.1.4.jar.sha1 b/client/rest/licenses/httpclient5-5.1.4.jar.sha1
deleted file mode 100644
index 3c0cb1335fb88..0000000000000
--- a/client/rest/licenses/httpclient5-5.1.4.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-208f9eed6d6ab709e2ae7a75b457ef60c0baefa5
\ No newline at end of file
diff --git a/client/rest/licenses/httpclient5-5.2.1.jar.sha1 b/client/rest/licenses/httpclient5-5.2.1.jar.sha1
new file mode 100644
index 0000000000000..3555fe22f8e12
--- /dev/null
+++ b/client/rest/licenses/httpclient5-5.2.1.jar.sha1
@@ -0,0 +1 @@
+0c900514d3446d9ce5d9dbd90c21192048125440
\ No newline at end of file
diff --git a/client/rest/licenses/httpcore5-5.1.5.jar.sha1 b/client/rest/licenses/httpcore5-5.1.5.jar.sha1
deleted file mode 100644
index 8da253152e970..0000000000000
--- a/client/rest/licenses/httpcore5-5.1.5.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-df9da3a1fa2351c4790245400ed28d78a8ddd3fc
\ No newline at end of file
diff --git a/client/rest/licenses/httpcore5-5.2.2.jar.sha1 b/client/rest/licenses/httpcore5-5.2.2.jar.sha1
new file mode 100644
index 0000000000000..b641256c7d4a4
--- /dev/null
+++ b/client/rest/licenses/httpcore5-5.2.2.jar.sha1
@@ -0,0 +1 @@
+6da28f5aa6c2b129ef49632e041a5203ce7507b2
\ No newline at end of file
diff --git a/client/rest/licenses/httpcore5-h2-5.1.5.jar.sha1 b/client/rest/licenses/httpcore5-h2-5.1.5.jar.sha1
deleted file mode 100644
index 097e6cc2a3be8..0000000000000
--- a/client/rest/licenses/httpcore5-h2-5.1.5.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-624660339afd5006d427457e6b10b10b32fd86f1
\ No newline at end of file
diff --git a/client/rest/licenses/httpcore5-h2-5.2.2.jar.sha1 b/client/rest/licenses/httpcore5-h2-5.2.2.jar.sha1
new file mode 100644
index 0000000000000..94bc0fa49bdb0
--- /dev/null
+++ b/client/rest/licenses/httpcore5-h2-5.2.2.jar.sha1
@@ -0,0 +1 @@
+54ee1ed58fe8ac40be1083ea9873a6c734939ab9
\ No newline at end of file
diff --git a/client/sniffer/build.gradle b/client/sniffer/build.gradle
index 9823bc9afd347..f645b2dbbc933 100644
--- a/client/sniffer/build.gradle
+++ b/client/sniffer/build.gradle
@@ -30,11 +30,15 @@
 apply plugin: 'opensearch.build'
 apply plugin: 'opensearch.publish'
 
-targetCompatibility = JavaVersion.VERSION_11
-sourceCompatibility = JavaVersion.VERSION_11
+java {
+  targetCompatibility = JavaVersion.VERSION_11
+  sourceCompatibility = JavaVersion.VERSION_11
+}
 
-group = 'org.opensearch.client'
-archivesBaseName = 'opensearch-rest-client-sniffer'
+base {
+  group = 'org.opensearch.client'
+  archivesBaseName = 'opensearch-rest-client-sniffer'
+}
 
 dependencies {
   api project(":client:rest")
diff --git a/client/sniffer/licenses/httpclient5-5.1.4.jar.sha1 b/client/sniffer/licenses/httpclient5-5.1.4.jar.sha1
deleted file mode 100644
index 3c0cb1335fb88..0000000000000
--- a/client/sniffer/licenses/httpclient5-5.1.4.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-208f9eed6d6ab709e2ae7a75b457ef60c0baefa5
\ No newline at end of file
diff --git a/client/sniffer/licenses/httpclient5-5.2.1.jar.sha1 b/client/sniffer/licenses/httpclient5-5.2.1.jar.sha1
new file mode 100644
index 0000000000000..3555fe22f8e12
--- /dev/null
+++ b/client/sniffer/licenses/httpclient5-5.2.1.jar.sha1
@@ -0,0 +1 @@
+0c900514d3446d9ce5d9dbd90c21192048125440
\ No newline at end of file
diff --git a/client/sniffer/licenses/httpcore5-5.1.5.jar.sha1 b/client/sniffer/licenses/httpcore5-5.1.5.jar.sha1
deleted file mode 100644
index 8da253152e970..0000000000000
--- a/client/sniffer/licenses/httpcore5-5.1.5.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-df9da3a1fa2351c4790245400ed28d78a8ddd3fc
\ No newline at end of file
diff --git a/client/sniffer/licenses/httpcore5-5.2.2.jar.sha1 b/client/sniffer/licenses/httpcore5-5.2.2.jar.sha1
new file mode 100644
index 0000000000000..b641256c7d4a4
--- /dev/null
+++ b/client/sniffer/licenses/httpcore5-5.2.2.jar.sha1
@@ -0,0 +1 @@
+6da28f5aa6c2b129ef49632e041a5203ce7507b2
\ No newline at end of file
diff --git a/client/test/build.gradle b/client/test/build.gradle
index 13e9bd6b9e34a..f81a009389681 100644
--- a/client/test/build.gradle
+++ b/client/test/build.gradle
@@ -29,10 +29,14 @@
  */
 apply plugin: 'opensearch.build'
 
-targetCompatibility = JavaVersion.VERSION_11
-sourceCompatibility = JavaVersion.VERSION_11
+java {
+  targetCompatibility = JavaVersion.VERSION_11
+  sourceCompatibility = JavaVersion.VERSION_11
+}
 
-group = "${group}.client.test"
+base {
+  group = "${group}.client.test"
+}
 
 dependencies {
   api "org.apache.httpcomponents.core5:httpcore5:${versions.httpcore5}"
diff --git a/distribution/archives/integ-test-zip/build.gradle b/distribution/archives/integ-test-zip/build.gradle
index f3f848797961c..9418223b0a44d 100644
--- a/distribution/archives/integ-test-zip/build.gradle
+++ b/distribution/archives/integ-test-zip/build.gradle
@@ -36,7 +36,10 @@ apply plugin: 'opensearch.rest-test'
 apply plugin: 'opensearch.publish'
 apply plugin: 'com.netflix.nebula.maven-publish'
 
-group = "org.opensearch.distribution.integ-test-zip"
+base {
+  group = "org.opensearch.distribution.integ-test-zip"
+  archivesBaseName = "opensearch"
+}
 
 integTest {
   dependsOn assemble
@@ -48,7 +51,6 @@ processTestResources {
 }
 
 // make the pom file name use opensearch instead of the project name
-archivesBaseName = "opensearch"
 ext.buildDist = parent.tasks.named("buildIntegTestZip")
 
 publishing {
diff --git a/distribution/tools/java-version-checker/build.gradle b/distribution/tools/java-version-checker/build.gradle
index 9480a86ce6fb7..7fd16b910b293 100644
--- a/distribution/tools/java-version-checker/build.gradle
+++ b/distribution/tools/java-version-checker/build.gradle
@@ -11,8 +11,10 @@
 
 apply plugin: 'opensearch.build'
 
-sourceCompatibility = JavaVersion.VERSION_11
-targetCompatibility = JavaVersion.VERSION_11
+java {
+  sourceCompatibility = JavaVersion.VERSION_11
+  targetCompatibility = JavaVersion.VERSION_11
+}
 
 // targetting very old java versions enables a warning by default on newer JDK: disable it.
 compileJava.options.compilerArgs += '-Xlint:-options'
diff --git a/distribution/tools/launchers/build.gradle b/distribution/tools/launchers/build.gradle
index 7ebe5c7e64416..e75267f7c4a74 100644
--- a/distribution/tools/launchers/build.gradle
+++ b/distribution/tools/launchers/build.gradle
@@ -38,7 +38,9 @@ dependencies {
   testImplementation "org.hamcrest:hamcrest:${versions.hamcrest}"
 }
 
-archivesBaseName = 'opensearch-launchers'
+base {
+  archivesBaseName = 'opensearch-launchers'
+}
 
 tasks.withType(CheckForbiddenApis).configureEach {
   replaceSignatureFiles 'jdk-signatures'
diff --git a/distribution/tools/plugin-cli/build.gradle b/distribution/tools/plugin-cli/build.gradle
index 477f66625e124..e68fbf8d6fc3c 100644
--- a/distribution/tools/plugin-cli/build.gradle
+++ b/distribution/tools/plugin-cli/build.gradle
@@ -30,7 +30,9 @@
 
 apply plugin: 'opensearch.build'
 
-archivesBaseName = 'opensearch-plugin-cli'
+base {
+  archivesBaseName = 'opensearch-plugin-cli'
+}
 
 dependencies {
   compileOnly project(":server")
diff --git a/distribution/tools/upgrade-cli/build.gradle b/distribution/tools/upgrade-cli/build.gradle
index cb87faf7788fa..54d51936159ec 100644
--- a/distribution/tools/upgrade-cli/build.gradle
+++ b/distribution/tools/upgrade-cli/build.gradle
@@ -9,7 +9,9 @@
 
 apply plugin: 'opensearch.build'
 
-archivesBaseName = 'opensearch-upgrade-cli'
+base {
+  archivesBaseName = 'opensearch-upgrade-cli'
+}
 
 dependencies {
   compileOnly project(":server")
diff --git a/doc-tools/build.gradle b/doc-tools/build.gradle
index c47097c3d6035..e6ace21420dda 100644
--- a/doc-tools/build.gradle
+++ b/doc-tools/build.gradle
@@ -2,8 +2,10 @@ plugins {
     id 'java'
 }
 
-group 'org.opensearch'
-version '1.0.0-SNAPSHOT'
+base {
+  group 'org.opensearch'
+  version '1.0.0-SNAPSHOT'
+}
 
 repositories {
     mavenCentral()
diff --git a/gradle.properties b/gradle.properties
index 73df0940ce181..7c359ed2b652c 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -21,6 +21,9 @@ org.gradle.jvmargs=-Xmx3g -XX:+HeapDumpOnOutOfMemoryError -Xss2m \
     --add-exports jdk.compiler/com.sun.tools.javac.util=ALL-UNNAMED
 options.forkOptions.memoryMaximumSize=3g
 
+# Disable Gradle Enterprise Gradle plugin's test retry
+systemProp.gradle.enterprise.testretry.enabled=false
+
 # Disable duplicate project id detection
 # See https://docs.gradle.org/current/userguide/upgrading_version_6.html#duplicate_project_names_may_cause_publication_to_fail
 systemProp.org.gradle.dependency.duplicate.project.detection=false
diff --git a/gradle/code-coverage.gradle b/gradle/code-coverage.gradle
index d5a717b5ea720..dfb4ddba24113 100644
--- a/gradle/code-coverage.gradle
+++ b/gradle/code-coverage.gradle
@@ -19,7 +19,7 @@ repositories {
 
 allprojects {
   plugins.withId('jacoco') {
-    jacoco.toolVersion = '0.8.9'
+    jacoco.toolVersion = '0.8.10'
   }
 }
 
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
index c1962a79e29d3..033e24c4cdf41 100644
Binary files a/gradle/wrapper/gradle-wrapper.jar and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index ee9745cc621ae..f00d0c8442459 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -11,7 +11,7 @@
 
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.1.1-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.2-all.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionSha256Sum=5625a0ae20fe000d9225d000b36909c7a0e0e8dda61c19b12da769add847c975
+distributionSha256Sum=5022b0b25fe182b0e50867e77f484501dba44feeea88f5c1f13b6b4660463640
diff --git a/gradlew b/gradlew
index aeb74cbb43e39..fcb6fca147c0c 100755
--- a/gradlew
+++ b/gradlew
@@ -130,10 +130,13 @@ location of your Java installation."
     fi
 else
     JAVACMD=java
-    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+    if ! command -v java >/dev/null 2>&1
+    then
+        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
 
 Please set the JAVA_HOME variable in your environment to match the
 location of your Java installation."
+    fi
 fi
 
 # Increase the maximum file descriptors if we can.
diff --git a/libs/common/build.gradle b/libs/common/build.gradle
index 003a04ad4bfa7..973fe30d09842 100644
--- a/libs/common/build.gradle
+++ b/libs/common/build.gradle
@@ -13,7 +13,9 @@ import org.opensearch.gradle.info.BuildParams
 
 apply plugin: 'opensearch.publish'
 
-archivesBaseName = 'opensearch-common'
+base {
+  archivesBaseName = 'opensearch-common'
+}
 
 dependencies {
   // This dependency is used only by :libs:core for null-checking interop with other tools
diff --git a/libs/core/build.gradle b/libs/core/build.gradle
index 65d507c37b3ff..46b6f4471731f 100644
--- a/libs/core/build.gradle
+++ b/libs/core/build.gradle
@@ -32,7 +32,9 @@ import org.opensearch.gradle.info.BuildParams
 
 apply plugin: 'opensearch.publish'
 
-archivesBaseName = 'opensearch-core'
+base {
+  archivesBaseName = 'opensearch-core'
+}
 
 // we want to keep the JDKs in our IDEs set to JDK 8 until minimum JDK is bumped to 11 so we do not include this source set in our IDEs
 if (!isEclipse) {
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/DefaultSpanScope.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/DefaultSpanScope.java
new file mode 100644
index 0000000000000..58e9e0abad739
--- /dev/null
+++ b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/DefaultSpanScope.java
@@ -0,0 +1,70 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.tracing;
+
+import java.util.function.Consumer;
+
+/**
+ * Default implementation of Scope
+ */
+public class DefaultSpanScope implements SpanScope {
+
+    private final Span span;
+
+    private final Consumer<Span> onCloseConsumer;
+
+    /**
+     * Creates Scope instance for the given span
+     *
+     * @param span underlying span
+     * @param onCloseConsumer consumer to execute on scope close
+     */
+    public DefaultSpanScope(Span span, Consumer<Span> onCloseConsumer) {
+        this.span = span;
+        this.onCloseConsumer = onCloseConsumer;
+    }
+
+    @Override
+    public void addSpanAttribute(String key, String value) {
+        span.addAttribute(key, value);
+    }
+
+    @Override
+    public void addSpanAttribute(String key, long value) {
+        span.addAttribute(key, value);
+    }
+
+    @Override
+    public void addSpanAttribute(String key, double value) {
+        span.addAttribute(key, value);
+    }
+
+    @Override
+    public void addSpanAttribute(String key, boolean value) {
+        span.addAttribute(key, value);
+    }
+
+    @Override
+    public void addSpanEvent(String event) {
+        span.addEvent(event);
+    }
+
+    @Override
+    public void setError(Exception exception) {
+        span.setError(exception);
+    }
+
+    /**
+     * Executes the runnable to end the scope
+     */
+    @Override
+    public void close() {
+        onCloseConsumer.accept(span);
+    }
+}
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/DefaultTracer.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/DefaultTracer.java
index ab9110af7c3ab..783edd238c1c2 100644
--- a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/DefaultTracer.java
+++ b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/DefaultTracer.java
@@ -13,8 +13,8 @@
 
 /**
  *
- * The default tracer implementation. This class implements the basic logic for span lifecycle and its state management.
- * It also handles tracing context propagation between spans.
+ * The default tracer implementation. It handles tracing context propagation between spans by maintaining
+ * current active span in its storage
  *
  *
  */
@@ -36,41 +36,11 @@ public DefaultTracer(TracingTelemetry tracingTelemetry, TracerContextStorage<Str
     }
 
     @Override
-    public Scope startSpan(String spanName) {
+    public SpanScope startSpan(String spanName) {
         Span span = createSpan(spanName, getCurrentSpan());
         setCurrentSpanInContext(span);
         addDefaultAttributes(span);
-        return new ScopeImpl(() -> endSpan(span));
-    }
-
-    @Override
-    public void addSpanAttribute(String key, String value) {
-        Span currentSpan = getCurrentSpan();
-        currentSpan.addAttribute(key, value);
-    }
-
-    @Override
-    public void addSpanAttribute(String key, long value) {
-        Span currentSpan = getCurrentSpan();
-        currentSpan.addAttribute(key, value);
-    }
-
-    @Override
-    public void addSpanAttribute(String key, double value) {
-        Span currentSpan = getCurrentSpan();
-        currentSpan.addAttribute(key, value);
-    }
-
-    @Override
-    public void addSpanAttribute(String key, boolean value) {
-        Span currentSpan = getCurrentSpan();
-        currentSpan.addAttribute(key, value);
-    }
-
-    @Override
-    public void addSpanEvent(String event) {
-        Span currentSpan = getCurrentSpan();
-        currentSpan.addEvent(event);
+        return new DefaultSpanScope(span, (scopeSpan) -> endSpan(scopeSpan));
     }
 
     @Override
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/Scope.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/Scope.java
deleted file mode 100644
index 52f4eaf648eea..0000000000000
--- a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/Scope.java
+++ /dev/null
@@ -1,26 +0,0 @@
-/*
- * SPDX-License-Identifier: Apache-2.0
- *
- * The OpenSearch Contributors require contributions made to
- * this file be licensed under the Apache-2.0 license or a
- * compatible open source license.
- */
-
-package org.opensearch.telemetry.tracing;
-
-/**
- * An auto-closeable that represents scope of the span.
- * It is recommended that you use this class with a try-with-resources block:
- */
-public interface Scope extends AutoCloseable {
-    /**
-     * No-op Scope implementation
-     */
-    Scope NO_OP = () -> {};
-
-    /**
-     * closes the scope
-     */
-    @Override
-    void close();
-}
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/ScopeImpl.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/ScopeImpl.java
deleted file mode 100644
index 30a7ac7fa90e7..0000000000000
--- a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/ScopeImpl.java
+++ /dev/null
@@ -1,33 +0,0 @@
-/*
- * SPDX-License-Identifier: Apache-2.0
- *
- * The OpenSearch Contributors require contributions made to
- * this file be licensed under the Apache-2.0 license or a
- * compatible open source license.
- */
-
-package org.opensearch.telemetry.tracing;
-
-/**
- * Executes the runnable on close
- */
-public class ScopeImpl implements Scope {
-
-    private Runnable runnableOnClose;
-
-    /**
-     * Creates Scope instance
-     * @param runnableOnClose runnable to execute on scope close
-     */
-    public ScopeImpl(Runnable runnableOnClose) {
-        this.runnableOnClose = runnableOnClose;
-    }
-
-    /**
-     * Executes the runnable to end the scope
-     */
-    @Override
-    public void close() {
-        runnableOnClose.run();
-    }
-}
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/Span.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/Span.java
index 0710b8a22a37f..d60b4e60adece 100644
--- a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/Span.java
+++ b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/Span.java
@@ -62,6 +62,13 @@ public interface Span {
      */
     void addAttribute(String key, Boolean value);
 
+    /**
+     * Records error in the span
+     *
+     * @param exception exception to be recorded
+     */
+    void setError(Exception exception);
+
     /**
      * Adds an event in the span
      *
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/SpanScope.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/SpanScope.java
new file mode 100644
index 0000000000000..cf67165d889bc
--- /dev/null
+++ b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/SpanScope.java
@@ -0,0 +1,74 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.tracing;
+
+import org.opensearch.telemetry.tracing.noop.NoopSpanScope;
+
+/**
+ * An auto-closeable that represents scope of the span.
+ * It provides interface for all the span operations.
+ */
+public interface SpanScope extends AutoCloseable {
+    /**
+     * No-op Scope implementation
+     */
+    SpanScope NO_OP = new NoopSpanScope();
+
+    /**
+     * Adds string attribute to the {@link Span}.
+     *
+     * @param key   attribute key
+     * @param value attribute value
+     */
+    void addSpanAttribute(String key, String value);
+
+    /**
+     * Adds long attribute to the {@link Span}.
+     *
+     * @param key   attribute key
+     * @param value attribute value
+     */
+    void addSpanAttribute(String key, long value);
+
+    /**
+     * Adds double attribute to the {@link Span}.
+     *
+     * @param key   attribute key
+     * @param value attribute value
+     */
+    void addSpanAttribute(String key, double value);
+
+    /**
+     * Adds boolean attribute to the {@link Span}.
+     *
+     * @param key   attribute key
+     * @param value attribute value
+     */
+    void addSpanAttribute(String key, boolean value);
+
+    /**
+     * Adds an event to the {@link Span}.
+     *
+     * @param event event name
+     */
+    void addSpanEvent(String event);
+
+    /**
+     * Records error in the span
+     *
+     * @param exception exception to be recorded
+     */
+    void setError(Exception exception);
+
+    /**
+     * closes the scope
+     */
+    @Override
+    void close();
+}
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/Tracer.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/Tracer.java
index fcc091eb39c48..d422b58aa0a9f 100644
--- a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/Tracer.java
+++ b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/Tracer.java
@@ -11,7 +11,7 @@
 import java.io.Closeable;
 
 /**
- * Tracer is the interface used to create a {@link Span} and interact with current active {@link Span}.
+ * Tracer is the interface used to create a {@link Span}
  * It automatically handles the context propagation between threads, tasks, nodes etc.
  *
  * All methods on the Tracer object are multi-thread safe.
@@ -24,44 +24,6 @@ public interface Tracer extends Closeable {
      * @param spanName span name
      * @return scope of the span, must be closed with explicit close or with try-with-resource
      */
-    Scope startSpan(String spanName);
+    SpanScope startSpan(String spanName);
 
-    /**
-     * Adds string attribute to the current active {@link Span}.
-     *
-     * @param key   attribute key
-     * @param value attribute value
-     */
-    void addSpanAttribute(String key, String value);
-
-    /**
-     * Adds long attribute to the current active {@link Span}.
-     *
-     * @param key   attribute key
-     * @param value attribute value
-     */
-    void addSpanAttribute(String key, long value);
-
-    /**
-     * Adds double attribute to the current active {@link Span}.
-     *
-     * @param key   attribute key
-     * @param value attribute value
-     */
-    void addSpanAttribute(String key, double value);
-
-    /**
-     * Adds boolean attribute to the current active {@link Span}.
-     *
-     * @param key   attribute key
-     * @param value attribute value
-     */
-    void addSpanAttribute(String key, boolean value);
-
-    /**
-     * Adds an event to the current active {@link Span}.
-     *
-     * @param event event name
-     */
-    void addSpanEvent(String event);
 }
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/noop/NoopSpanScope.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/noop/NoopSpanScope.java
new file mode 100644
index 0000000000000..c0dbaf65ba48b
--- /dev/null
+++ b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/noop/NoopSpanScope.java
@@ -0,0 +1,57 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.tracing.noop;
+
+import org.opensearch.telemetry.tracing.SpanScope;
+
+/**
+ * No-op implementation of SpanScope
+ */
+public final class NoopSpanScope implements SpanScope {
+
+    /**
+     * No-args constructor
+     */
+    public NoopSpanScope() {}
+
+    @Override
+    public void addSpanAttribute(String key, String value) {
+
+    }
+
+    @Override
+    public void addSpanAttribute(String key, long value) {
+
+    }
+
+    @Override
+    public void addSpanAttribute(String key, double value) {
+
+    }
+
+    @Override
+    public void addSpanAttribute(String key, boolean value) {
+
+    }
+
+    @Override
+    public void addSpanEvent(String event) {
+
+    }
+
+    @Override
+    public void setError(Exception exception) {
+
+    }
+
+    @Override
+    public void close() {
+
+    }
+}
diff --git a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/noop/NoopTracer.java b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/noop/NoopTracer.java
index 18fc60e41e54d..a66cbcf4fef52 100644
--- a/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/noop/NoopTracer.java
+++ b/libs/telemetry/src/main/java/org/opensearch/telemetry/tracing/noop/NoopTracer.java
@@ -8,7 +8,7 @@
 
 package org.opensearch.telemetry.tracing.noop;
 
-import org.opensearch.telemetry.tracing.Scope;
+import org.opensearch.telemetry.tracing.SpanScope;
 import org.opensearch.telemetry.tracing.Tracer;
 
 /**
@@ -24,49 +24,8 @@ public class NoopTracer implements Tracer {
     private NoopTracer() {}
 
     @Override
-    public Scope startSpan(String spanName) {
-        return Scope.NO_OP;
-    }
-
-    /**
-     * @param key   attribute key
-     * @param value attribute value
-     */
-    @Override
-    public void addSpanAttribute(String key, String value) {
-
-    }
-
-    /**
-     * @param key   attribute key
-     * @param value attribute value
-     */
-    @Override
-    public void addSpanAttribute(String key, long value) {
-
-    }
-
-    /**
-     * @param key   attribute key
-     * @param value attribute value
-     */
-    @Override
-    public void addSpanAttribute(String key, double value) {
-
-    }
-
-    /**
-     * @param key   attribute key
-     * @param value attribute value
-     */
-    @Override
-    public void addSpanAttribute(String key, boolean value) {
-
-    }
-
-    @Override
-    public void addSpanEvent(String event) {
-
+    public SpanScope startSpan(String spanName) {
+        return SpanScope.NO_OP;
     }
 
     @Override
diff --git a/libs/telemetry/src/test/java/org/opensearch/telemetry/tracing/DefaultSpanScopeTests.java b/libs/telemetry/src/test/java/org/opensearch/telemetry/tracing/DefaultSpanScopeTests.java
new file mode 100644
index 0000000000000..eea6b77ce6e1e
--- /dev/null
+++ b/libs/telemetry/src/test/java/org/opensearch/telemetry/tracing/DefaultSpanScopeTests.java
@@ -0,0 +1,79 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.telemetry.tracing;
+
+import org.opensearch.test.OpenSearchTestCase;
+
+import java.util.function.Consumer;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+
+public class DefaultSpanScopeTests extends OpenSearchTestCase {
+
+    @SuppressWarnings("unchecked")
+    public void testClose() {
+        Span mockSpan = mock(Span.class);
+        Consumer<Span> mockConsumer = mock(Consumer.class);
+        DefaultSpanScope defaultSpanScope = new DefaultSpanScope(mockSpan, mockConsumer);
+        defaultSpanScope.close();
+
+        verify(mockConsumer).accept(mockSpan);
+    }
+
+    public void testAddSpanAttributeString() {
+        Span mockSpan = mock(Span.class);
+        DefaultSpanScope defaultSpanScope = new DefaultSpanScope(mockSpan, null);
+        defaultSpanScope.addSpanAttribute("key", "value");
+
+        verify(mockSpan).addAttribute("key", "value");
+    }
+
+    public void testAddSpanAttributeLong() {
+        Span mockSpan = mock(Span.class);
+        DefaultSpanScope defaultSpanScope = new DefaultSpanScope(mockSpan, null);
+        defaultSpanScope.addSpanAttribute("key", 1L);
+
+        verify(mockSpan).addAttribute("key", 1L);
+    }
+
+    public void testAddSpanAttributeDouble() {
+        Span mockSpan = mock(Span.class);
+        DefaultSpanScope defaultSpanScope = new DefaultSpanScope(mockSpan, null);
+        defaultSpanScope.addSpanAttribute("key", 1.0);
+
+        verify(mockSpan).addAttribute("key", 1.0);
+    }
+
+    public void testAddSpanAttributeBoolean() {
+        Span mockSpan = mock(Span.class);
+        DefaultSpanScope defaultSpanScope = new DefaultSpanScope(mockSpan, null);
+        defaultSpanScope.addSpanAttribute("key", true);
+
+        verify(mockSpan).addAttribute("key", true);
+    }
+
+    public void testAddEvent() {
+        Span mockSpan = mock(Span.class);
+        DefaultSpanScope defaultSpanScope = new DefaultSpanScope(mockSpan, null);
+        defaultSpanScope.addSpanEvent("eventName");
+
+        verify(mockSpan).addEvent("eventName");
+    }
+
+    public void testSetError() {
+        Span mockSpan = mock(Span.class);
+        DefaultSpanScope defaultSpanScope = new DefaultSpanScope(mockSpan, null);
+        Exception ex = new Exception("error");
+        defaultSpanScope.setError(ex);
+
+        verify(mockSpan).setError(ex);
+    }
+
+}
diff --git a/libs/telemetry/src/test/java/org/opensearch/telemetry/tracing/DefaultTracerTests.java b/libs/telemetry/src/test/java/org/opensearch/telemetry/tracing/DefaultTracerTests.java
index f0e8f3c2e2344..2b7a379b0051a 100644
--- a/libs/telemetry/src/test/java/org/opensearch/telemetry/tracing/DefaultTracerTests.java
+++ b/libs/telemetry/src/test/java/org/opensearch/telemetry/tracing/DefaultTracerTests.java
@@ -45,57 +45,12 @@ public void testCreateSpan() {
 
     public void testEndSpanByClosingScope() {
         DefaultTracer defaultTracer = new DefaultTracer(mockTracingTelemetry, mockTracerContextStorage);
-        try (Scope scope = defaultTracer.startSpan("span_name")) {
+        try (SpanScope spanScope = defaultTracer.startSpan("span_name")) {
             verify(mockTracerContextStorage).put(TracerContextStorage.CURRENT_SPAN, mockSpan);
         }
         verify(mockTracerContextStorage).put(TracerContextStorage.CURRENT_SPAN, mockParentSpan);
     }
 
-    public void testAddSpanAttributeString() {
-        Tracer defaultTracer = new DefaultTracer(mockTracingTelemetry, mockTracerContextStorage);
-        defaultTracer.startSpan("span_name");
-
-        defaultTracer.addSpanAttribute("key", "value");
-
-        verify(mockSpan).addAttribute("key", "value");
-    }
-
-    public void testAddSpanAttributeLong() {
-        Tracer defaultTracer = new DefaultTracer(mockTracingTelemetry, mockTracerContextStorage);
-        defaultTracer.startSpan("span_name");
-
-        defaultTracer.addSpanAttribute("key", 1L);
-
-        verify(mockSpan).addAttribute("key", 1L);
-    }
-
-    public void testAddSpanAttributeDouble() {
-        Tracer defaultTracer = new DefaultTracer(mockTracingTelemetry, mockTracerContextStorage);
-        defaultTracer.startSpan("span_name");
-
-        defaultTracer.addSpanAttribute("key", 1.0);
-
-        verify(mockSpan).addAttribute("key", 1.0);
-    }
-
-    public void testAddSpanAttributeBoolean() {
-        Tracer defaultTracer = new DefaultTracer(mockTracingTelemetry, mockTracerContextStorage);
-        defaultTracer.startSpan("span_name");
-
-        defaultTracer.addSpanAttribute("key", true);
-
-        verify(mockSpan).addAttribute("key", true);
-    }
-
-    public void testAddEvent() {
-        Tracer defaultTracer = new DefaultTracer(mockTracingTelemetry, mockTracerContextStorage);
-        defaultTracer.startSpan("span_name");
-
-        defaultTracer.addSpanEvent("eventName");
-
-        verify(mockSpan).addEvent("eventName");
-    }
-
     public void testClose() throws IOException {
         Tracer defaultTracer = new DefaultTracer(mockTracingTelemetry, mockTracerContextStorage);
 
diff --git a/modules/lang-painless/build.gradle b/modules/lang-painless/build.gradle
index 6c1785e6faf6b..3b3f2a7f9ca38 100644
--- a/modules/lang-painless/build.gradle
+++ b/modules/lang-painless/build.gradle
@@ -109,7 +109,7 @@ tasks.register("apiJavadoc", Javadoc) {
   source = sourceSets.main.allJava
   classpath = sourceSets.main.runtimeClasspath
   include '**/org/opensearch/painless/api/'
-  destinationDir = new File(docsDir, 'apiJavadoc')
+  destinationDir = new File(file(java.docsDir), 'apiJavadoc')
 }
 
 tasks.register("apiJavadocJar", Jar) {
diff --git a/modules/lang-painless/spi/build.gradle b/modules/lang-painless/spi/build.gradle
index 7811ee0e41dd8..59a77870b4987 100644
--- a/modules/lang-painless/spi/build.gradle
+++ b/modules/lang-painless/spi/build.gradle
@@ -31,8 +31,10 @@
 apply plugin: 'opensearch.build'
 apply plugin: 'opensearch.publish'
 
-group = 'org.opensearch.plugin'
-archivesBaseName = 'opensearch-scripting-painless-spi'
+base {
+  group = 'org.opensearch.plugin'
+  archivesBaseName = 'opensearch-scripting-painless-spi'
+}
 
 dependencies {
   api project(":server")
diff --git a/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/FilterQueryRequestProcessor.java b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/FilterQueryRequestProcessor.java
index 7deb8faa03af6..d8862aa59cede 100644
--- a/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/FilterQueryRequestProcessor.java
+++ b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/FilterQueryRequestProcessor.java
@@ -13,12 +13,12 @@
 import org.opensearch.common.xcontent.LoggingDeprecationHandler;
 import org.opensearch.common.xcontent.XContentType;
 import org.opensearch.common.xcontent.json.JsonXContent;
-import org.opensearch.core.ParseField;
 import org.opensearch.core.xcontent.NamedXContentRegistry;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.core.xcontent.XContentParser;
 import org.opensearch.index.query.BoolQueryBuilder;
 import org.opensearch.index.query.QueryBuilder;
+import org.opensearch.ingest.ConfigurationUtils;
 import org.opensearch.search.builder.SearchSourceBuilder;
 import org.opensearch.search.pipeline.Processor;
 import org.opensearch.search.pipeline.SearchRequestProcessor;
@@ -89,8 +89,8 @@ public SearchRequest processRequest(SearchRequest request) throws Exception {
     }
 
     static class Factory implements Processor.Factory<SearchRequestProcessor> {
+        private static final String QUERY_KEY = "query";
         private final NamedXContentRegistry namedXContentRegistry;
-        public static final ParseField QUERY_FIELD = new ParseField("query");
 
         Factory(NamedXContentRegistry namedXContentRegistry) {
             this.namedXContentRegistry = namedXContentRegistry;
@@ -101,30 +101,21 @@ public FilterQueryRequestProcessor create(
             Map<String, Processor.Factory<SearchRequestProcessor>> processorFactories,
             String tag,
             String description,
-            Map<String, Object> config
+            Map<String, Object> config,
+            PipelineContext pipelineContext
         ) throws Exception {
+            Map<String, Object> query = ConfigurationUtils.readOptionalMap(TYPE, tag, config, QUERY_KEY);
+            if (query == null) {
+                throw new IllegalArgumentException("Did not specify the " + QUERY_KEY + " property in processor of type " + TYPE);
+            }
             try (
-                XContentBuilder builder = XContentBuilder.builder(JsonXContent.jsonXContent).map(config);
+                XContentBuilder builder = XContentBuilder.builder(JsonXContent.jsonXContent).map(query);
                 InputStream stream = BytesReference.bytes(builder).streamInput();
                 XContentParser parser = XContentType.JSON.xContent()
                     .createParser(namedXContentRegistry, LoggingDeprecationHandler.INSTANCE, stream)
             ) {
-                XContentParser.Token token = parser.nextToken();
-                assert token == XContentParser.Token.START_OBJECT;
-                String currentFieldName = null;
-                while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
-                    if (token == XContentParser.Token.FIELD_NAME) {
-                        currentFieldName = parser.currentName();
-                    } else if (token == XContentParser.Token.START_OBJECT) {
-                        if (QUERY_FIELD.match(currentFieldName, parser.getDeprecationHandler())) {
-                            return new FilterQueryRequestProcessor(tag, description, parseInnerQueryBuilder(parser));
-                        }
-                    }
-                }
+                return new FilterQueryRequestProcessor(tag, description, parseInnerQueryBuilder(parser));
             }
-            throw new IllegalArgumentException(
-                "Did not specify the " + QUERY_FIELD.getPreferredName() + " property in processor of type " + TYPE
-            );
         }
     }
 }
diff --git a/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/RenameFieldResponseProcessor.java b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/RenameFieldResponseProcessor.java
index 4c40dda5928f0..c8b3c06a71562 100644
--- a/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/RenameFieldResponseProcessor.java
+++ b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/RenameFieldResponseProcessor.java
@@ -140,7 +140,8 @@ public RenameFieldResponseProcessor create(
             Map<String, Processor.Factory<SearchResponseProcessor>> processorFactories,
             String tag,
             String description,
-            Map<String, Object> config
+            Map<String, Object> config,
+            PipelineContext pipelineContext
         ) throws Exception {
             String oldField = ConfigurationUtils.readStringProperty(TYPE, tag, config, "field");
             String newField = ConfigurationUtils.readStringProperty(TYPE, tag, config, "target_field");
diff --git a/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/ScriptRequestProcessor.java b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/ScriptRequestProcessor.java
index 015411e0701a4..43ab3d4622d6b 100644
--- a/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/ScriptRequestProcessor.java
+++ b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/ScriptRequestProcessor.java
@@ -29,7 +29,8 @@
 import org.opensearch.search.pipeline.common.helpers.SearchRequestMap;
 
 import java.io.InputStream;
-import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 
 import static org.opensearch.ingest.ConfigurationUtils.newConfigurationException;
@@ -127,6 +128,8 @@ SearchScript getPrecompiledSearchScript() {
      * Factory class for creating {@link ScriptRequestProcessor}.
      */
     public static final class Factory implements Processor.Factory<SearchRequestProcessor> {
+        private static final List<String> SCRIPT_CONFIG_KEYS = List.of("id", "source", "inline", "lang", "params", "options");
+
         private final ScriptService scriptService;
 
         /**
@@ -138,33 +141,29 @@ public Factory(ScriptService scriptService) {
             this.scriptService = scriptService;
         }
 
-        /**
-         * Creates a new instance of {@link ScriptRequestProcessor}.
-         *
-         * @param registry The registry of processor factories.
-         * @param processorTag The processor's tag.
-         * @param description The processor's description.
-         * @param config The configuration options for the processor.
-         * @return The created {@link ScriptRequestProcessor} instance.
-         * @throws Exception if an error occurs during the creation process.
-         */
         @Override
         public ScriptRequestProcessor create(
             Map<String, Processor.Factory<SearchRequestProcessor>> registry,
             String processorTag,
             String description,
-            Map<String, Object> config
+            Map<String, Object> config,
+            PipelineContext pipelineContext
         ) throws Exception {
+            Map<String, Object> scriptConfig = new HashMap<>();
+            for (String key : SCRIPT_CONFIG_KEYS) {
+                Object val = config.remove(key);
+                if (val != null) {
+                    scriptConfig.put(key, val);
+                }
+            }
             try (
-                XContentBuilder builder = XContentBuilder.builder(JsonXContent.jsonXContent).map(config);
+                XContentBuilder builder = XContentBuilder.builder(JsonXContent.jsonXContent).map(scriptConfig);
                 InputStream stream = BytesReference.bytes(builder).streamInput();
                 XContentParser parser = XContentType.JSON.xContent()
                     .createParser(NamedXContentRegistry.EMPTY, LoggingDeprecationHandler.INSTANCE, stream)
             ) {
                 Script script = Script.parse(parser);
 
-                Arrays.asList("id", "source", "inline", "lang", "params", "options").forEach(config::remove);
-
                 // verify script is able to be compiled before successfully creating processor.
                 SearchScript searchScript = null;
                 try {
diff --git a/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/SearchPipelineCommonModulePlugin.java b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/SearchPipelineCommonModulePlugin.java
index dc25de460fdba..49681b80fdead 100644
--- a/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/SearchPipelineCommonModulePlugin.java
+++ b/modules/search-pipeline-common/src/main/java/org/opensearch/search/pipeline/common/SearchPipelineCommonModulePlugin.java
@@ -33,7 +33,7 @@ public SearchPipelineCommonModulePlugin() {}
      * @return A map of processor factories, where the keys are the processor types and the values are the corresponding factory instances.
      */
     @Override
-    public Map<String, Processor.Factory<SearchRequestProcessor>> getRequestProcessors(Processor.Parameters parameters) {
+    public Map<String, Processor.Factory<SearchRequestProcessor>> getRequestProcessors(Parameters parameters) {
         return Map.of(
             FilterQueryRequestProcessor.TYPE,
             new FilterQueryRequestProcessor.Factory(parameters.namedXContentRegistry),
@@ -43,7 +43,7 @@ public Map<String, Processor.Factory<SearchRequestProcessor>> getRequestProcesso
     }
 
     @Override
-    public Map<String, Processor.Factory<SearchResponseProcessor>> getResponseProcessors(Processor.Parameters parameters) {
+    public Map<String, Processor.Factory<SearchResponseProcessor>> getResponseProcessors(Parameters parameters) {
         return Map.of(RenameFieldResponseProcessor.TYPE, new RenameFieldResponseProcessor.Factory());
     }
 }
diff --git a/modules/search-pipeline-common/src/test/java/org/opensearch/search/pipeline/common/FilterQueryRequestProcessorTests.java b/modules/search-pipeline-common/src/test/java/org/opensearch/search/pipeline/common/FilterQueryRequestProcessorTests.java
index 1f355ac97c801..ecf746af556a2 100644
--- a/modules/search-pipeline-common/src/test/java/org/opensearch/search/pipeline/common/FilterQueryRequestProcessorTests.java
+++ b/modules/search-pipeline-common/src/test/java/org/opensearch/search/pipeline/common/FilterQueryRequestProcessorTests.java
@@ -16,6 +16,7 @@
 import org.opensearch.test.AbstractBuilderTestCase;
 
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.Map;
 
 public class FilterQueryRequestProcessorTests extends AbstractBuilderTestCase {
@@ -37,15 +38,14 @@ public void testFilterQuery() throws Exception {
 
     public void testFactory() throws Exception {
         FilterQueryRequestProcessor.Factory factory = new FilterQueryRequestProcessor.Factory(this.xContentRegistry());
-        FilterQueryRequestProcessor processor = factory.create(
-            Collections.emptyMap(),
-            null,
-            null,
-            Map.of("query", Map.of("term", Map.of("field", "value")))
-        );
+        Map<String, Object> configMap = new HashMap<>(Map.of("query", Map.of("term", Map.of("field", "value"))));
+        FilterQueryRequestProcessor processor = factory.create(Collections.emptyMap(), null, null, configMap, null);
         assertEquals(new TermQueryBuilder("field", "value"), processor.filterQuery);
 
         // Missing "query" parameter:
-        expectThrows(IllegalArgumentException.class, () -> factory.create(Collections.emptyMap(), null, null, Collections.emptyMap()));
+        expectThrows(
+            IllegalArgumentException.class,
+            () -> factory.create(Collections.emptyMap(), null, null, Collections.emptyMap(), null)
+        );
     }
 }
diff --git a/modules/search-pipeline-common/src/test/java/org/opensearch/search/pipeline/common/RenameFieldResponseProcessorTests.java b/modules/search-pipeline-common/src/test/java/org/opensearch/search/pipeline/common/RenameFieldResponseProcessorTests.java
index a2fc7f6acfa7c..7f3a2acfbdc08 100644
--- a/modules/search-pipeline-common/src/test/java/org/opensearch/search/pipeline/common/RenameFieldResponseProcessorTests.java
+++ b/modules/search-pipeline-common/src/test/java/org/opensearch/search/pipeline/common/RenameFieldResponseProcessorTests.java
@@ -115,12 +115,15 @@ public void testFactory() throws Exception {
         config.put("target_field", newField);
 
         RenameFieldResponseProcessor.Factory factory = new RenameFieldResponseProcessor.Factory();
-        RenameFieldResponseProcessor processor = factory.create(Collections.emptyMap(), null, null, config);
+        RenameFieldResponseProcessor processor = factory.create(Collections.emptyMap(), null, null, config, null);
         assertEquals(processor.getType(), "rename_field");
         assertEquals(processor.getOldField(), oldField);
         assertEquals(processor.getNewField(), newField);
         assertFalse(processor.isIgnoreMissing());
 
-        expectThrows(OpenSearchParseException.class, () -> factory.create(Collections.emptyMap(), null, null, Collections.emptyMap()));
+        expectThrows(
+            OpenSearchParseException.class,
+            () -> factory.create(Collections.emptyMap(), null, null, Collections.emptyMap(), null)
+        );
     }
 }
diff --git a/modules/search-pipeline-common/src/yamlRestTest/resources/rest-api-spec/test/search_pipeline/50_script_processor.yml b/modules/search-pipeline-common/src/yamlRestTest/resources/rest-api-spec/test/search_pipeline/50_script_processor.yml
index 9d855e8a1861a..7a01e68acf75c 100644
--- a/modules/search-pipeline-common/src/yamlRestTest/resources/rest-api-spec/test/search_pipeline/50_script_processor.yml
+++ b/modules/search-pipeline-common/src/yamlRestTest/resources/rest-api-spec/test/search_pipeline/50_script_processor.yml
@@ -17,6 +17,7 @@ teardown:
             "request_processors": [
               {
                 "script" : {
+                  "tag": "empty_script",
                   "lang": "painless",
                   "source" : ""
                 }
@@ -38,6 +39,7 @@ teardown:
             "request_processors": [
               {
                 "script" : {
+                  "tag": "working",
                   "lang" : "painless",
                   "source" : "ctx._source['size'] += 10; ctx._source['from'] = ctx._source['from'] <= 0 ? ctx._source['from'] : ctx._source['from'] - 1 ; ctx._source['explain'] = !ctx._source['explain']; ctx._source['version'] = !ctx._source['version']; ctx._source['seq_no_primary_term'] = !ctx._source['seq_no_primary_term']; ctx._source['track_scores'] = !ctx._source['track_scores']; ctx._source['track_total_hits'] = 1; ctx._source['min_score'] -= 0.9; ctx._source['terminate_after'] += 2; ctx._source['profile'] = !ctx._source['profile'];"
                 }
diff --git a/plugins/discovery-azure-classic/licenses/httpclient-4.5.13.jar.sha1 b/plugins/discovery-azure-classic/licenses/httpclient-4.5.13.jar.sha1
deleted file mode 100644
index 3281e21595b39..0000000000000
--- a/plugins/discovery-azure-classic/licenses/httpclient-4.5.13.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-e5f6cae5ca7ecaac1ec2827a9e2d65ae2869cada
\ No newline at end of file
diff --git a/plugins/discovery-azure-classic/licenses/httpclient-4.5.14.jar.sha1 b/plugins/discovery-azure-classic/licenses/httpclient-4.5.14.jar.sha1
new file mode 100644
index 0000000000000..66e05851c2e3c
--- /dev/null
+++ b/plugins/discovery-azure-classic/licenses/httpclient-4.5.14.jar.sha1
@@ -0,0 +1 @@
+1194890e6f56ec29177673f2f12d0b8e627dec98
\ No newline at end of file
diff --git a/plugins/discovery-azure-classic/licenses/httpcore-4.4.15.jar.sha1 b/plugins/discovery-azure-classic/licenses/httpcore-4.4.15.jar.sha1
deleted file mode 100644
index 42a03b5d7a376..0000000000000
--- a/plugins/discovery-azure-classic/licenses/httpcore-4.4.15.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-7f2e0c573eaa7a74bac2e89b359e1f73d92a0a1d
\ No newline at end of file
diff --git a/plugins/discovery-azure-classic/licenses/httpcore-4.4.16.jar.sha1 b/plugins/discovery-azure-classic/licenses/httpcore-4.4.16.jar.sha1
new file mode 100644
index 0000000000000..172110694b5bd
--- /dev/null
+++ b/plugins/discovery-azure-classic/licenses/httpcore-4.4.16.jar.sha1
@@ -0,0 +1 @@
+51cf043c87253c9f58b539c9f7e44c8894223850
\ No newline at end of file
diff --git a/plugins/discovery-ec2/licenses/httpclient-4.5.13.jar.sha1 b/plugins/discovery-ec2/licenses/httpclient-4.5.13.jar.sha1
deleted file mode 100644
index 3281e21595b39..0000000000000
--- a/plugins/discovery-ec2/licenses/httpclient-4.5.13.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-e5f6cae5ca7ecaac1ec2827a9e2d65ae2869cada
\ No newline at end of file
diff --git a/plugins/discovery-ec2/licenses/httpclient-4.5.14.jar.sha1 b/plugins/discovery-ec2/licenses/httpclient-4.5.14.jar.sha1
new file mode 100644
index 0000000000000..66e05851c2e3c
--- /dev/null
+++ b/plugins/discovery-ec2/licenses/httpclient-4.5.14.jar.sha1
@@ -0,0 +1 @@
+1194890e6f56ec29177673f2f12d0b8e627dec98
\ No newline at end of file
diff --git a/plugins/discovery-ec2/licenses/httpcore-4.4.15.jar.sha1 b/plugins/discovery-ec2/licenses/httpcore-4.4.15.jar.sha1
deleted file mode 100644
index 42a03b5d7a376..0000000000000
--- a/plugins/discovery-ec2/licenses/httpcore-4.4.15.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-7f2e0c573eaa7a74bac2e89b359e1f73d92a0a1d
\ No newline at end of file
diff --git a/plugins/discovery-ec2/licenses/httpcore-4.4.16.jar.sha1 b/plugins/discovery-ec2/licenses/httpcore-4.4.16.jar.sha1
new file mode 100644
index 0000000000000..172110694b5bd
--- /dev/null
+++ b/plugins/discovery-ec2/licenses/httpcore-4.4.16.jar.sha1
@@ -0,0 +1 @@
+51cf043c87253c9f58b539c9f7e44c8894223850
\ No newline at end of file
diff --git a/plugins/discovery-gce/licenses/httpclient-4.5.13.jar.sha1 b/plugins/discovery-gce/licenses/httpclient-4.5.13.jar.sha1
deleted file mode 100644
index 3281e21595b39..0000000000000
--- a/plugins/discovery-gce/licenses/httpclient-4.5.13.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-e5f6cae5ca7ecaac1ec2827a9e2d65ae2869cada
\ No newline at end of file
diff --git a/plugins/discovery-gce/licenses/httpclient-4.5.14.jar.sha1 b/plugins/discovery-gce/licenses/httpclient-4.5.14.jar.sha1
new file mode 100644
index 0000000000000..66e05851c2e3c
--- /dev/null
+++ b/plugins/discovery-gce/licenses/httpclient-4.5.14.jar.sha1
@@ -0,0 +1 @@
+1194890e6f56ec29177673f2f12d0b8e627dec98
\ No newline at end of file
diff --git a/plugins/discovery-gce/licenses/httpcore-4.4.15.jar.sha1 b/plugins/discovery-gce/licenses/httpcore-4.4.15.jar.sha1
deleted file mode 100644
index 42a03b5d7a376..0000000000000
--- a/plugins/discovery-gce/licenses/httpcore-4.4.15.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-7f2e0c573eaa7a74bac2e89b359e1f73d92a0a1d
\ No newline at end of file
diff --git a/plugins/discovery-gce/licenses/httpcore-4.4.16.jar.sha1 b/plugins/discovery-gce/licenses/httpcore-4.4.16.jar.sha1
new file mode 100644
index 0000000000000..172110694b5bd
--- /dev/null
+++ b/plugins/discovery-gce/licenses/httpcore-4.4.16.jar.sha1
@@ -0,0 +1 @@
+51cf043c87253c9f58b539c9f7e44c8894223850
\ No newline at end of file
diff --git a/plugins/repository-azure/build.gradle b/plugins/repository-azure/build.gradle
index e67ea7ab0a11e..4edb9e0b1913e 100644
--- a/plugins/repository-azure/build.gradle
+++ b/plugins/repository-azure/build.gradle
@@ -58,8 +58,8 @@ dependencies {
   api 'com.azure:azure-storage-blob:12.22.2'
   api 'org.reactivestreams:reactive-streams:1.0.4'
   api 'io.projectreactor:reactor-core:3.5.6'
-  api 'io.projectreactor.netty:reactor-netty:1.1.7'
-  api 'io.projectreactor.netty:reactor-netty-core:1.1.7'
+  api 'io.projectreactor.netty:reactor-netty:1.1.8'
+  api 'io.projectreactor.netty:reactor-netty-core:1.1.8'
   api 'io.projectreactor.netty:reactor-netty-http:1.1.8'
   api "org.slf4j:slf4j-api:${versions.slf4j}"
   api "com.fasterxml.jackson.core:jackson-annotations:${versions.jackson}"
diff --git a/plugins/repository-azure/licenses/reactor-netty-1.1.7.jar.sha1 b/plugins/repository-azure/licenses/reactor-netty-1.1.7.jar.sha1
deleted file mode 100644
index 01a9b1d34d52f..0000000000000
--- a/plugins/repository-azure/licenses/reactor-netty-1.1.7.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-c16497c29f96ea7b1db538cb0ddde55d9be173fe
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/reactor-netty-1.1.8.jar.sha1 b/plugins/repository-azure/licenses/reactor-netty-1.1.8.jar.sha1
new file mode 100644
index 0000000000000..6b6bf1903b16c
--- /dev/null
+++ b/plugins/repository-azure/licenses/reactor-netty-1.1.8.jar.sha1
@@ -0,0 +1 @@
+d53a9d7d0395285f4c81664494fcd61477626e32
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/reactor-netty-core-1.1.7.jar.sha1 b/plugins/repository-azure/licenses/reactor-netty-core-1.1.7.jar.sha1
deleted file mode 100644
index 62ed795cb11e9..0000000000000
--- a/plugins/repository-azure/licenses/reactor-netty-core-1.1.7.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-d38bb526a501f52c4476b03730c710a96f8fd35b
\ No newline at end of file
diff --git a/plugins/repository-azure/licenses/reactor-netty-core-1.1.8.jar.sha1 b/plugins/repository-azure/licenses/reactor-netty-core-1.1.8.jar.sha1
new file mode 100644
index 0000000000000..707631f4dfe0c
--- /dev/null
+++ b/plugins/repository-azure/licenses/reactor-netty-core-1.1.8.jar.sha1
@@ -0,0 +1 @@
+48999c4ae27cdcee5eaff9dfd150a8b64624f0f5
\ No newline at end of file
diff --git a/plugins/repository-hdfs/build.gradle b/plugins/repository-hdfs/build.gradle
index 7ac54544f7a1b..3c83e535a91d8 100644
--- a/plugins/repository-hdfs/build.gradle
+++ b/plugins/repository-hdfs/build.gradle
@@ -66,7 +66,7 @@ dependencies {
   }
   api 'org.apache.htrace:htrace-core4:4.2.0-incubating'
   api "org.apache.logging.log4j:log4j-core:${versions.log4j}"
-  api 'org.apache.avro:avro:1.11.1'
+  api 'org.apache.avro:avro:1.11.2'
   api 'com.google.code.gson:gson:2.10.1'
   runtimeOnly "com.google.guava:guava:${versions.guava}"
   api "commons-logging:commons-logging:${versions.commonslogging}"
diff --git a/plugins/repository-hdfs/licenses/avro-1.11.1.jar.sha1 b/plugins/repository-hdfs/licenses/avro-1.11.1.jar.sha1
deleted file mode 100644
index f03424516b44e..0000000000000
--- a/plugins/repository-hdfs/licenses/avro-1.11.1.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-81af5d4b9bdaaf4ba41bcb0df5241355ec34c630
\ No newline at end of file
diff --git a/plugins/repository-hdfs/licenses/avro-1.11.2.jar.sha1 b/plugins/repository-hdfs/licenses/avro-1.11.2.jar.sha1
new file mode 100644
index 0000000000000..ce1a894e0ce6d
--- /dev/null
+++ b/plugins/repository-hdfs/licenses/avro-1.11.2.jar.sha1
@@ -0,0 +1 @@
+97e62e8be2b37e849f1bdb5a4f08121d47cc9806
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/httpclient-4.5.13.jar.sha1 b/plugins/repository-s3/licenses/httpclient-4.5.13.jar.sha1
deleted file mode 100644
index 3281e21595b39..0000000000000
--- a/plugins/repository-s3/licenses/httpclient-4.5.13.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-e5f6cae5ca7ecaac1ec2827a9e2d65ae2869cada
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/httpclient-4.5.14.jar.sha1 b/plugins/repository-s3/licenses/httpclient-4.5.14.jar.sha1
new file mode 100644
index 0000000000000..66e05851c2e3c
--- /dev/null
+++ b/plugins/repository-s3/licenses/httpclient-4.5.14.jar.sha1
@@ -0,0 +1 @@
+1194890e6f56ec29177673f2f12d0b8e627dec98
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/httpcore-4.4.15.jar.sha1 b/plugins/repository-s3/licenses/httpcore-4.4.15.jar.sha1
deleted file mode 100644
index 42a03b5d7a376..0000000000000
--- a/plugins/repository-s3/licenses/httpcore-4.4.15.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-7f2e0c573eaa7a74bac2e89b359e1f73d92a0a1d
\ No newline at end of file
diff --git a/plugins/repository-s3/licenses/httpcore-4.4.16.jar.sha1 b/plugins/repository-s3/licenses/httpcore-4.4.16.jar.sha1
new file mode 100644
index 0000000000000..172110694b5bd
--- /dev/null
+++ b/plugins/repository-s3/licenses/httpcore-4.4.16.jar.sha1
@@ -0,0 +1 @@
+51cf043c87253c9f58b539c9f7e44c8894223850
\ No newline at end of file
diff --git a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3BlobContainer.java b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3BlobContainer.java
index cf749eeffd903..49ebce77a59ad 100644
--- a/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3BlobContainer.java
+++ b/plugins/repository-s3/src/main/java/org/opensearch/repositories/s3/S3BlobContainer.java
@@ -36,6 +36,7 @@
 import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.message.ParameterizedMessage;
 import org.opensearch.ExceptionsHelper;
+import org.opensearch.action.ActionListener;
 import org.opensearch.common.Nullable;
 import org.opensearch.common.SetOnce;
 import org.opensearch.common.blobstore.BlobContainer;
@@ -296,6 +297,35 @@ private static DeleteObjectsRequest bulkDelete(String bucket, List<String> blobs
             .build();
     }
 
+    @Override
+    public void listBlobsByPrefixInSortedOrder(
+        String blobNamePrefix,
+        int limit,
+        BlobNameSortOrder blobNameSortOrder,
+        ActionListener<List<BlobMetadata>> listener
+    ) {
+        // As AWS S3 returns list of keys in Lexicographic order, we don't have to fetch all the keys in order to sort them
+        // We fetch only keys as per the given limit to optimize the fetch. If provided sort order is not Lexicographic,
+        // we fall-back to default implementation of fetching all the keys and sorting them.
+        if (blobNameSortOrder != BlobNameSortOrder.LEXICOGRAPHIC) {
+            super.listBlobsByPrefixInSortedOrder(blobNamePrefix, limit, blobNameSortOrder, listener);
+        } else {
+            if (limit < 0) {
+                throw new IllegalArgumentException("limit should not be a negative value");
+            }
+            String prefix = blobNamePrefix == null ? keyPath : buildKey(blobNamePrefix);
+            try (AmazonS3Reference clientReference = blobStore.clientReference()) {
+                List<BlobMetadata> blobs = executeListing(clientReference, listObjectsRequest(prefix, limit), limit).stream()
+                    .flatMap(listing -> listing.contents().stream())
+                    .map(s3Object -> new PlainBlobMetadata(s3Object.key().substring(keyPath.length()), s3Object.size()))
+                    .collect(Collectors.toList());
+                listener.onResponse(blobs.subList(0, Math.min(limit, blobs.size())));
+            } catch (final Exception e) {
+                listener.onFailure(new IOException("Exception when listing blobs by prefix [" + prefix + "]", e));
+            }
+        }
+    }
+
     @Override
     public Map<String, BlobMetadata> listBlobsByPrefix(@Nullable String blobNamePrefix) throws IOException {
         String prefix = blobNamePrefix == null ? keyPath : buildKey(blobNamePrefix);
@@ -339,10 +369,25 @@ public Map<String, BlobContainer> children() throws IOException {
     }
 
     private static List<ListObjectsV2Response> executeListing(AmazonS3Reference clientReference, ListObjectsV2Request listObjectsRequest) {
+        return executeListing(clientReference, listObjectsRequest, -1);
+    }
+
+    private static List<ListObjectsV2Response> executeListing(
+        AmazonS3Reference clientReference,
+        ListObjectsV2Request listObjectsRequest,
+        int limit
+    ) {
         return SocketAccess.doPrivileged(() -> {
             final List<ListObjectsV2Response> results = new ArrayList<>();
+            int totalObjects = 0;
             ListObjectsV2Iterable listObjectsIterable = clientReference.get().listObjectsV2Paginator(listObjectsRequest);
-            listObjectsIterable.forEach(results::add);
+            for (ListObjectsV2Response listObjectsV2Response : listObjectsIterable) {
+                results.add(listObjectsV2Response);
+                totalObjects += listObjectsV2Response.contents().size();
+                if (limit != -1 && totalObjects > limit) {
+                    break;
+                }
+            }
             return results;
         });
     }
@@ -356,6 +401,10 @@ private ListObjectsV2Request listObjectsRequest(String keyPath) {
             .build();
     }
 
+    private ListObjectsV2Request listObjectsRequest(String keyPath, int limit) {
+        return listObjectsRequest(keyPath).toBuilder().maxKeys(Math.min(limit, 1000)).build();
+    }
+
     private String buildKey(String blobName) {
         return keyPath + blobName;
     }
diff --git a/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3BlobStoreContainerTests.java b/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3BlobStoreContainerTests.java
index ec16f216f1777..a2a7ca8d8bdd5 100644
--- a/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3BlobStoreContainerTests.java
+++ b/plugins/repository-s3/src/test/java/org/opensearch/repositories/s3/S3BlobStoreContainerTests.java
@@ -33,6 +33,9 @@
 package org.opensearch.repositories.s3;
 
 import org.mockito.ArgumentCaptor;
+import org.opensearch.action.ActionListener;
+import org.opensearch.common.blobstore.BlobContainer;
+import org.opensearch.common.blobstore.BlobMetadata;
 import org.opensearch.common.blobstore.BlobPath;
 import org.opensearch.common.blobstore.BlobStoreException;
 import org.opensearch.common.blobstore.DeleteResult;
@@ -74,9 +77,13 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.Comparator;
+import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Map;
 import java.util.NoSuchElementException;
+import java.util.Set;
 import java.util.UUID;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.stream.Collectors;
@@ -84,12 +91,12 @@
 
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.instanceOf;
+import static org.mockito.Mockito.when;
+import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.any;
 import static org.mockito.Mockito.doAnswer;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
+import static org.mockito.Mockito.times;
 
 public class S3BlobStoreContainerTests extends OpenSearchTestCase {
 
@@ -187,26 +194,34 @@ private static class MockListObjectsV2ResponseIterator implements Iterator<ListO
         private final long s3ObjectSize;
 
         private final AtomicInteger currInvocationCount = new AtomicInteger();
-        private final List<String> keysListed = new ArrayList<>();
+        private final List<String> keysListed;
         private final boolean throwExceptionOnNextInvocation;
 
         public MockListObjectsV2ResponseIterator(int totalPageCount, int s3ObjectsPerPage, long s3ObjectSize) {
-            this.totalPageCount = totalPageCount;
-            this.s3ObjectsPerPage = s3ObjectsPerPage;
-            this.s3ObjectSize = s3ObjectSize;
-            this.throwExceptionOnNextInvocation = false;
+            this(totalPageCount, s3ObjectsPerPage, s3ObjectSize, "");
+        }
+
+        public MockListObjectsV2ResponseIterator(int totalPageCount, int s3ObjectsPerPage, long s3ObjectSize, String blobPath) {
+            this(totalPageCount, s3ObjectsPerPage, s3ObjectSize, blobPath, false);
         }
 
         public MockListObjectsV2ResponseIterator(
             int totalPageCount,
             int s3ObjectsPerPage,
             long s3ObjectSize,
+            String blobPath,
             boolean throwExceptionOnNextInvocation
         ) {
             this.totalPageCount = totalPageCount;
             this.s3ObjectsPerPage = s3ObjectsPerPage;
             this.s3ObjectSize = s3ObjectSize;
             this.throwExceptionOnNextInvocation = throwExceptionOnNextInvocation;
+            keysListed = new ArrayList<>();
+            for (int i = 0; i < totalPageCount * s3ObjectsPerPage; i++) {
+                keysListed.add(blobPath + UUID.randomUUID().toString());
+            }
+            // S3 lists keys in lexicographic order
+            keysListed.sort(String::compareTo);
         }
 
         @Override
@@ -220,11 +235,12 @@ public ListObjectsV2Response next() {
                 throw SdkException.builder().build();
             }
             if (currInvocationCount.getAndIncrement() < totalPageCount) {
-                String s3ObjectKey = UUID.randomUUID().toString();
-                keysListed.add(s3ObjectKey);
-                return ListObjectsV2Response.builder()
-                    .contents(Collections.nCopies(s3ObjectsPerPage, S3Object.builder().key(s3ObjectKey).size(s3ObjectSize).build()))
-                    .build();
+                List<S3Object> s3Objects = new ArrayList<>();
+                for (int i = 0; i < s3ObjectsPerPage; i++) {
+                    String s3ObjectKey = keysListed.get((currInvocationCount.get() - 1) * s3ObjectsPerPage + i);
+                    s3Objects.add(S3Object.builder().key(s3ObjectKey).size(s3ObjectSize).build());
+                }
+                return ListObjectsV2Response.builder().contents(s3Objects).build();
             }
             throw new NoSuchElementException();
         }
@@ -232,6 +248,10 @@ public ListObjectsV2Response next() {
         public List<String> getKeysListed() {
             return keysListed;
         }
+
+        public int numberOfPagesFetched() {
+            return currInvocationCount.get();
+        }
     }
 
     public void testDelete() throws IOException {
@@ -273,10 +293,8 @@ public void testDelete() throws IOException {
         // keysDeleted will have blobPath also
         assertEquals(listObjectsV2ResponseIterator.getKeysListed().size(), keysDeleted.size() - 1);
         assertTrue(keysDeleted.contains(blobPath.buildAsString()));
-        assertArrayEquals(
-            listObjectsV2ResponseIterator.getKeysListed().toArray(String[]::new),
-            keysDeleted.stream().filter(key -> !blobPath.buildAsString().equals(key)).toArray(String[]::new)
-        );
+        keysDeleted.remove(blobPath.buildAsString());
+        assertEquals(new HashSet<>(listObjectsV2ResponseIterator.getKeysListed()), new HashSet<>(keysDeleted));
     }
 
     public void testDeleteItemLevelErrorsDuringDelete() {
@@ -772,4 +790,112 @@ private static void assertNumberOfMultiparts(final int expectedParts, final long
         assertEquals("Expected number of parts [" + expectedParts + "] but got [" + result.v1() + "]", expectedParts, (long) result.v1());
         assertEquals("Expected remaining [" + expectedRemaining + "] but got [" + result.v2() + "]", expectedRemaining, (long) result.v2());
     }
+
+    public void testListBlobsByPrefix() throws IOException {
+        final S3BlobStore blobStore = mock(S3BlobStore.class);
+        when(blobStore.getStatsMetricPublisher()).thenReturn(new StatsMetricPublisher());
+
+        final S3Client client = mock(S3Client.class);
+        final AmazonS3Reference clientReference = new AmazonS3Reference(client);
+        when(blobStore.clientReference()).thenReturn(clientReference);
+
+        BlobPath blobPath = mock(BlobPath.class);
+        when(blobPath.buildAsString()).thenReturn("/dummy/path");
+        final S3BlobContainer blobContainer = new S3BlobContainer(blobPath, blobStore);
+
+        final ListObjectsV2Iterable listObjectsV2Iterable = mock(ListObjectsV2Iterable.class);
+        when(client.listObjectsV2Paginator(any(ListObjectsV2Request.class))).thenReturn(listObjectsV2Iterable);
+
+        MockListObjectsV2ResponseIterator iterator = new MockListObjectsV2ResponseIterator(2, 5, 100);
+        when(listObjectsV2Iterable.iterator()).thenReturn(iterator);
+
+        Map<String, BlobMetadata> listOfBlobs = blobContainer.listBlobsByPrefix(null);
+        assertEquals(10, listOfBlobs.size());
+
+        Set<String> keys = iterator.keysListed.stream()
+            .map(s -> s.substring(blobPath.buildAsString().length()))
+            .collect(Collectors.toSet());
+        assertEquals(keys, listOfBlobs.keySet());
+    }
+
+    private void testListBlobsByPrefixInLexicographicOrder(
+        int limit,
+        int expectedNumberofPagesFetched,
+        BlobContainer.BlobNameSortOrder blobNameSortOrder
+    ) throws IOException {
+        final S3BlobStore blobStore = mock(S3BlobStore.class);
+        when(blobStore.getStatsMetricPublisher()).thenReturn(new StatsMetricPublisher());
+
+        final S3Client client = mock(S3Client.class);
+        final AmazonS3Reference clientReference = new AmazonS3Reference(client);
+        when(blobStore.clientReference()).thenReturn(clientReference);
+
+        BlobPath blobPath = mock(BlobPath.class);
+        when(blobPath.buildAsString()).thenReturn("/dummy/path");
+        final S3BlobContainer blobContainer = new S3BlobContainer(blobPath, blobStore);
+
+        final ListObjectsV2Iterable listObjectsV2Iterable = mock(ListObjectsV2Iterable.class);
+        when(client.listObjectsV2Paginator(any(ListObjectsV2Request.class))).thenReturn(listObjectsV2Iterable);
+
+        final MockListObjectsV2ResponseIterator iterator = new MockListObjectsV2ResponseIterator(2, 5, 100, blobPath.buildAsString());
+        when(listObjectsV2Iterable.iterator()).thenReturn(iterator);
+
+        if (limit >= 0) {
+            blobContainer.listBlobsByPrefixInSortedOrder(null, limit, blobNameSortOrder, new ActionListener<>() {
+                @Override
+                public void onResponse(List<BlobMetadata> blobMetadata) {
+                    int actualLimit = Math.max(0, Math.min(limit, 10));
+                    assertEquals(actualLimit, blobMetadata.size());
+
+                    List<String> keys = iterator.keysListed.stream()
+                        .map(s -> s.substring(blobPath.buildAsString().length()))
+                        .collect(Collectors.toList());
+                    Comparator<String> keysComparator = String::compareTo;
+                    if (blobNameSortOrder != BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC) {
+                        keysComparator = Collections.reverseOrder(String::compareTo);
+                    }
+                    keys.sort(keysComparator);
+                    List<String> sortedKeys = keys.subList(0, actualLimit);
+                    assertEquals(sortedKeys, blobMetadata.stream().map(BlobMetadata::name).collect(Collectors.toList()));
+                    assertEquals(expectedNumberofPagesFetched, iterator.numberOfPagesFetched());
+                }
+
+                @Override
+                public void onFailure(Exception e) {
+                    fail("blobContainer.listBlobsByPrefixInLexicographicOrder failed with exception: " + e.getMessage());
+                }
+            });
+        } else {
+            assertThrows(
+                IllegalArgumentException.class,
+                () -> blobContainer.listBlobsByPrefixInSortedOrder(null, limit, blobNameSortOrder, new ActionListener<>() {
+                    @Override
+                    public void onResponse(List<BlobMetadata> blobMetadata) {}
+
+                    @Override
+                    public void onFailure(Exception e) {}
+                })
+            );
+        }
+    }
+
+    public void testListBlobsByPrefixInLexicographicOrderWithNegativeLimit() throws IOException {
+        testListBlobsByPrefixInLexicographicOrder(-5, 0, BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC);
+    }
+
+    public void testListBlobsByPrefixInLexicographicOrderWithZeroLimit() throws IOException {
+        testListBlobsByPrefixInLexicographicOrder(0, 1, BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC);
+    }
+
+    public void testListBlobsByPrefixInLexicographicOrderWithLimitLessThanPageSize() throws IOException {
+        testListBlobsByPrefixInLexicographicOrder(2, 1, BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC);
+    }
+
+    public void testListBlobsByPrefixInLexicographicOrderWithLimitGreaterThanPageSize() throws IOException {
+        testListBlobsByPrefixInLexicographicOrder(8, 2, BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC);
+    }
+
+    public void testListBlobsByPrefixInLexicographicOrderWithLimitGreaterThanNumberOfRecords() throws IOException {
+        testListBlobsByPrefixInLexicographicOrder(12, 2, BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC);
+    }
 }
diff --git a/plugins/telemetry-otel/build.gradle b/plugins/telemetry-otel/build.gradle
index 7a56621be5f1e..2c275388cce38 100644
--- a/plugins/telemetry-otel/build.gradle
+++ b/plugins/telemetry-otel/build.gradle
@@ -54,3 +54,25 @@ thirdPartyAudit {
     'io.opentelemetry.sdk.autoconfigure.spi.traces.ConfigurableSpanExporterProvider'
   )
 }
+
+tasks.named("bundlePlugin").configure {
+  from('config/telemetry-otel') {
+    into 'config'
+  }
+}
+
+tasks.register("writeTestJavaPolicy") {
+  doLast {
+    final File tmp = file("${buildDir}/tmp")
+    if (tmp.exists() == false && tmp.mkdirs() == false) {
+      throw new GradleException("failed to create temporary directory [${tmp}]")
+    }
+    final File javaPolicy = file("${tmp}/java.policy")
+    javaPolicy.write(
+      [
+        "grant {",
+        "  permission java.io.FilePermission \"config\", \"read\";",
+        "};"
+      ].join("\n"))
+  }
+}
diff --git a/plugins/telemetry-otel/config/telemetry-otel/log4j2.properties b/plugins/telemetry-otel/config/telemetry-otel/log4j2.properties
new file mode 100644
index 0000000000000..544f42bd5513b
--- /dev/null
+++ b/plugins/telemetry-otel/config/telemetry-otel/log4j2.properties
@@ -0,0 +1,27 @@
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+# The OpenSearch Contributors require contributions made to
+# this file be licensed under the Apache-2.0 license or a
+# compatible open source license.
+#
+
+
+appender.tracing.type = RollingFile
+appender.tracing.name = tracing
+appender.tracing.fileName = ${sys:opensearch.logs.base_path}${sys:file.separator}${sys:opensearch.logs.cluster_name}_otel_traces.log
+appender.tracing.filePermissions = rw-r-----
+appender.tracing.layout.type = PatternLayout
+appender.tracing.layout.pattern = %m%n
+appender.tracing.filePattern = ${sys:opensearch.logs.base_path}${sys:file.separator}${sys:opensearch.logs.cluster_name}_otel_traces-%i.log.gz
+appender.tracing.policies.type = Policies
+appender.tracing.policies.size.type = SizeBasedTriggeringPolicy
+appender.tracing.policies.size.size = 1GB
+appender.tracing.strategy.type = DefaultRolloverStrategy
+appender.tracing.strategy.max = 4
+
+
+logger.exporter.name = io.opentelemetry.exporter.logging.LoggingSpanExporter
+logger.exporter.level = INFO
+logger.exporter.appenderRef.tracing.ref = tracing
+logger.exporter.additivity = false
diff --git a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelResourceProvider.java b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelResourceProvider.java
index 04bade9ec942a..292165979c2f2 100644
--- a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelResourceProvider.java
+++ b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelResourceProvider.java
@@ -42,7 +42,7 @@ private OTelResourceProvider() {}
     public static OpenTelemetry get(Settings settings) {
         return get(
             settings,
-            new LoggingSpanExporter(),
+            LoggingSpanExporter.create(),
             ContextPropagators.create(W3CTraceContextPropagator.getInstance()),
             Sampler.alwaysOn()
         );
diff --git a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelSpan.java b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelSpan.java
index 23a2d9baa3e6e..ba63df4ae47a1 100644
--- a/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelSpan.java
+++ b/plugins/telemetry-otel/src/main/java/org/opensearch/telemetry/tracing/OTelSpan.java
@@ -9,6 +9,7 @@
 package org.opensearch.telemetry.tracing;
 
 import io.opentelemetry.api.trace.Span;
+import io.opentelemetry.api.trace.StatusCode;
 
 /**
  * Default implementation of {@link Span} using Otel span. It keeps a reference of OpenTelemetry Span and handles span
@@ -48,6 +49,11 @@ public void addAttribute(String key, Boolean value) {
         delegateSpan.setAttribute(key, value);
     }
 
+    @Override
+    public void setError(Exception exception) {
+        delegateSpan.setStatus(StatusCode.ERROR, exception.getMessage());
+    }
+
     @Override
     public void addEvent(String event) {
         delegateSpan.addEvent(event);
diff --git a/qa/mixed-cluster/src/test/java/org/opensearch/backwards/IndexingIT.java b/qa/mixed-cluster/src/test/java/org/opensearch/backwards/IndexingIT.java
index b867b90af333c..f1f469544f634 100644
--- a/qa/mixed-cluster/src/test/java/org/opensearch/backwards/IndexingIT.java
+++ b/qa/mixed-cluster/src/test/java/org/opensearch/backwards/IndexingIT.java
@@ -113,8 +113,6 @@ private void printClusterRouting() throws IOException, ParseException {
     /**
      * This test verifies that segment replication does not break when primary shards are on lower OS version. It does this
      * by verifying replica shards contains same number of documents as primary's.
-     *
-     * @throws Exception
      */
     public void testIndexingWithPrimaryOnBwcNodes() throws Exception {
         if (UPGRADE_FROM_VERSION.before(Version.V_2_4_0)) {
@@ -164,8 +162,6 @@ public void testIndexingWithPrimaryOnBwcNodes() throws Exception {
      * This test creates a cluster with primary on higher version but due to {@link org.opensearch.cluster.routing.allocation.decider.NodeVersionAllocationDecider};
      * replica shard allocation on lower OpenSearch version is prevented. Thus, this test though cover the use case where
      * primary shard containing nodes are running on higher OS version while replicas are unassigned.
-     *
-     * @throws Exception
      */
     public void testIndexingWithReplicaOnBwcNodes() throws Exception {
         if (UPGRADE_FROM_VERSION.before(Version.V_2_4_0)) {
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/test/index/100_partial_flat_object.yml b/rest-api-spec/src/main/resources/rest-api-spec/test/index/100_partial_flat_object.yml
new file mode 100644
index 0000000000000..91e4127da9c32
--- /dev/null
+++ b/rest-api-spec/src/main/resources/rest-api-spec/test/index/100_partial_flat_object.yml
@@ -0,0 +1,606 @@
+---
+# The test setup includes:
+# - Create flat_object mapping for test_partial_flat_object index
+# - Index two example documents
+# - Refresh the index so it is ready for search tests
+
+setup:
+  - do:
+      indices.create:
+        index: test_partial_flat_object
+        body:
+          mappings:
+            properties:
+              issue:
+                properties:
+                  number:
+                    type: "integer"
+                  labels:
+                    type: "flat_object"
+  - do:
+      index:
+        index: test_partial_flat_object
+        id: 1
+        body: {
+          "issue": {
+            "number": 123,
+            "labels": {
+              "version": "2.2",
+              "backport": [
+                "2.0",
+                "1.9"
+              ],
+              "category": {
+                "type": "API",
+                "level": "bug"
+              },
+              "createdDate": "2023-01-01",
+              "comment": [ [ "Doe","Shipped" ],[ "John","Approved" ] ],
+              "views": 288,
+              "priority": 5.00
+            }
+          }
+        }
+
+  - do:
+      index:
+        index: test_partial_flat_object
+        id: 2
+        body: {
+          "issue": {
+            "number": 456,
+            "labels": {
+              "author": "Liu",
+              "version": "2.1",
+              "backport": [
+                "2.0",
+                "1.3"
+              ],
+              "category": {
+                "type": "API",
+                "level": "enhancement"
+              },
+              "createdDate": "2023-02-01",
+              "comment": [ [ "Mike","LGTM" ],[ "John","Approved" ] ],
+              "views": 3333,
+              "priority": 1.50
+            }
+          }
+        }
+
+  - do:
+      index:
+        index: test_partial_flat_object
+        id: 3
+        body: {
+          "issue": {
+            "number": 999,
+            "labels": [ {
+              "version": "1.1",
+              "backport": [
+                "1.0",
+                "0.9"
+              ],
+              "category": {
+                "type": "Module",
+                "level": "feature"
+              }
+            } ]
+          }
+        }
+
+  - do:
+      indices.refresh:
+        index: test_partial_flat_object
+---
+# Delete Index when connection is teardown
+teardown:
+  - do:
+      indices.delete:
+        index: test_partial_flat_object
+
+
+---
+# Verify that mappings under the catalog field did not expand
+# and no dynamic fields were created.
+"Mappings":
+  - skip:
+      version: " - 2.99.99"
+      reason: "flat_object is introduced in 3.0.0 in main branch"
+
+  - do:
+      indices.get_mapping:
+        index: test_partial_flat_object
+  - is_true: test_partial_flat_object.mappings
+  - match: { test_partial_flat_object.mappings.properties.issue.properties.number.type: integer }
+  - match: { test_partial_flat_object.mappings.properties.issue.properties.labels.type: flat_object }
+  # https://github.com/opensearch-project/OpenSearch/tree/main/rest-api-spec/src/main/resources/rest-api-spec/test#length
+  - length: { test_partial_flat_object.mappings.properties.issue.properties: 2 }
+  - length: { test_partial_flat_object.mappings.properties.issue.properties.labels: 1 }
+
+
+---
+"Supported queries":
+  - skip:
+      version: " - 2.99.99"
+      reason: "flat_object is introduced in 3.0.0 in main branch"
+
+
+  # Verify Document Count
+  - do:
+      search:
+        body: {
+          query: {
+            match_all: { }
+          }
+        }
+
+  - length: { hits.hits: 3 }
+
+  # Match Query with exact dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            match: { "issue.labels.version": "2.1" }
+          }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.labels.version: "2.1" }
+
+  # Match Query without exact dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            match: { issue.labels: "2.1" }
+          }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.labels.version: "2.1" }
+
+  # Multi Match Query with exact dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            multi_match: {
+              "query": "2.0",
+              "fields": [ "issue.labels.version", "issue.labels.backport" ]
+            }
+          }
+        }
+
+  - length: { hits.hits: 2 }
+  - match: { hits.hits.0._source.issue.labels.backport: [ "2.0", "1.9" ] }
+  - match: { hits.hits.1._source.issue.labels.backport: [ "2.0", "1.3" ] }
+
+  # Term Query1 with exact dot path for date
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            term: { issue.labels.createdDate: "2023-01-01" }
+          }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.labels.createdDate: "2023-01-01" }
+
+  # Term Query1 without exact dot path for date
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            term: { issue.labels: "2023-01-01" }
+          }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.labels.createdDate: "2023-01-01" }
+
+
+  # Term Query2 with dot path for string
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            term: { "issue.labels.category.type": "API" }
+          }
+        }
+
+  - length: { hits.hits: 2 }
+  - match: { hits.hits.0._source.issue.labels.category.type: "API" }
+  - match: { hits.hits.1._source.issue.labels.category.type: "API" }
+
+  # Term Query2 without exact dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            term: { issue.labels: "API" }
+          }
+        }
+
+  - length: { hits.hits: 2 }
+  - match: { hits.hits.0._source.issue.labels.category.type: "API" }
+  - match: { hits.hits.1._source.issue.labels.category.type: "API" }
+
+  # Term Query3 with dot path for array
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            term: { issue.labels.backport: "1.9" }
+          }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.labels.backport: [ "2.0", "1.9" ] }
+
+  # Term Query3 without dot path for array
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            term: { issue.labels: "1.9" }
+          }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.labels.backport: [ "2.0", "1.9" ] }
+
+  # Term Query4 with  dot path for nested-array
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            term: { issue.labels.comment: "LGTM" }
+          }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.labels.comment: [ [ "Mike","LGTM" ],[ "John","Approved" ] ] }
+
+  # Term Query4 without dot path for nested-array
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            term: { issue.labels: "LGTM" }
+          }
+        }
+
+  # Term Query5 with  dot path for array
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            term: { issue.labels.category.type: "Module" }
+          }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.labels.0.category.type: "Module" }
+
+  # Term Query5 without dot path for array
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            term: { issue.labels: "Module" }
+          }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.labels.0.category.type: "Module" }
+
+  # Terms Query without dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            terms: { issue.labels: [ "John","Mike" ] }
+          }
+        }
+
+  - length: { hits.hits: 2 }
+  - match: { hits.hits.0._source.issue.labels.comment: [ [ "Doe","Shipped" ],[ "John","Approved" ] ] }
+  - match: { hits.hits.1._source.issue.labels.comment: [ [ "Mike","LGTM" ],[ "John","Approved" ] ] }
+
+  # Terms Query with dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            terms: { issue.labels.comment: [ "John","Mike" ] }
+          }
+        }
+
+  - length: { hits.hits: 2 }
+  - match: { hits.hits.0._source.issue.labels.comment: [ [ "Doe","Shipped" ],[ "John","Approved" ] ] }
+  - match: { hits.hits.1._source.issue.labels.comment: [ [ "Mike","LGTM" ],[ "John","Approved" ] ] }
+
+  # Prefix Query with dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            "prefix": {
+              "issue.labels.comment": {
+                "value": "Mi"
+              }
+            }
+          }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.labels.comment: [ [ "Mike","LGTM" ],[ "John","Approved" ] ] }
+
+  # Prefix Query without dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            "prefix": {
+              "issue.labels": {
+                "value": "Mi"
+              }
+            }
+          }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.labels.comment: [ [ "Mike","LGTM" ],[ "John","Approved" ] ] }
+
+  # Range Query with dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            "range": {
+              "issue.labels.version": {
+                "gte": "2.1",
+                "lte": "3.0"
+              }
+            }
+          }
+        }
+
+  - length: { hits.hits: 2 }
+  - match: { hits.hits.0._source.issue.labels.version: "2.2" }
+  - match: { hits.hits.1._source.issue.labels.version: "2.1" }
+
+  # Range Query without dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            "range": {
+              "issue.labels": {
+                "gte": "2.1",
+                "lte": "3.0"
+              }
+            }
+          }
+        }
+
+  - length: { hits.hits: 2 }
+  - match: { hits.hits.0._source.issue.labels.version: "2.2" }
+  - match: { hits.hits.1._source.issue.labels.version: "2.1" }
+
+  # Range Query with integer input with dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            "range": {
+              "issue.labels.views": {
+                "gte": 3000,
+                "lte": 4000
+              }
+            }
+          }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.labels.views: 3333 }
+
+  # Range Query with integer input without dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            "range": {
+              "issue.labels": {
+                "gte": 3000,
+                "lte": 4000
+              }
+            }
+          }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.labels.views: 3333 }
+
+
+  # Range Query with double input with dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            "range": {
+              "issue.labels.priority": {
+                "gte": 4.1234,
+                "lte": 5.1234
+              }
+            }
+          }
+        }
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.labels.priority: 5.00 }
+
+  # Range Query with double input without dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            "range": {
+              "issue.labels": {
+                "gte": 4.1234,
+                "lte": 5.1234
+              }
+            }
+          }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.labels.priority: 5.00 }
+
+
+  # Exists Query with dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            "exists": {
+              "field": issue.labels.priority
+            }
+          }
+        }
+
+  - length: { hits.hits: 2 }
+
+  # Exists Query with nested dot path, use the flat_object_field_name.last_key
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            "exists": {
+              "field": issue.labels.type
+            }
+          }
+        }
+
+  - length: { hits.hits: 3 }
+
+  # Exists Query without dot path for the flat_object_field_name
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            "exists": {
+              "field": issue.labels
+            }
+          }
+        }
+
+  - length: { hits.hits: 3 }
+
+  # Exists Query2 with dot path for one hit
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            "exists": {
+              "field": issue.labels.author
+            }
+          }
+        }
+
+  - length: { hits.hits: 1 }
+
+  # Query_string Query without dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            "query_string": {
+              "fields": [ "issue.labels" ],
+              "query": "Doe OR Mike"
+            }
+          }
+        }
+
+  - length: { hits.hits: 2 }
+  - match: { hits.hits.0._source.issue.labels.comment: [ [ "Doe","Shipped" ],[ "John","Approved" ] ] }
+  - match: { hits.hits.1._source.issue.labels.comment: [ [ "Mike","LGTM" ],[ "John","Approved" ] ] }
+
+  # Query_string Query with dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            "query_string": {
+              "fields": [ "issue.labels.comment" ],
+              "query": "Doe OR Mike"
+            }
+          }
+        }
+
+  - length: { hits.hits: 2 }
+  - match: { hits.hits.0._source.issue.labels.comment: [ [ "Doe","Shipped" ],[ "John","Approved" ] ] }
+  - match: { hits.hits.1._source.issue.labels.comment: [ [ "Mike","LGTM" ],[ "John","Approved" ] ] }
+
+  # Simple_query_string Query without full dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            "simple_query_string": {
+              "query": "Doe",
+              "fields": [ "issue.labels" ]
+            }
+          }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.labels.comment: [ [ "Doe","Shipped" ],[ "John","Approved" ] ] }
+
+  # Simple_query_string Query with dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            "simple_query_string": {
+              "query": "Doe",
+              "fields": [ "issue.labels.comment" ]
+            }
+          }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.labels.comment: [ [ "Doe","Shipped" ],[ "John","Approved" ] ] }
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/test/index/105_partial_flat_object_nested.yml b/rest-api-spec/src/main/resources/rest-api-spec/test/index/105_partial_flat_object_nested.yml
new file mode 100644
index 0000000000000..ce172c2773e1f
--- /dev/null
+++ b/rest-api-spec/src/main/resources/rest-api-spec/test/index/105_partial_flat_object_nested.yml
@@ -0,0 +1,636 @@
+---
+# The test setup includes:
+# - Create flat_object mapping for test_partial_flat_object_nested index
+# - Index two example documents
+# - Refresh the index so it is ready for search tests
+
+setup:
+  - do:
+      indices.create:
+        index: test_partial_flat_object_nested
+        body:
+          mappings:
+            properties:
+              issue:
+                type: "nested"
+                properties:
+                  number:
+                    type: "integer"
+                  labels:
+                    type: "flat_object"
+  - do:
+      index:
+        index: test_partial_flat_object_nested
+        id: 1
+        body: {
+          "issue": [
+            {
+              "number": 123,
+              "labels": {
+                "version": "2.2",
+                "backport": [
+                  "2.0",
+                  "1.9"
+                ],
+                "category": {
+                  "type": "API",
+                  "level": "bug"
+                },
+                "createdDate": "2023-01-01",
+                "comment": [ [ "Doe","Shipped" ],[ "John","Approved" ] ],
+                "views": 288,
+                "priority": 5.00
+              }
+            }
+          ]
+        }
+
+  - do:
+      index:
+        index: test_partial_flat_object_nested
+        id: 2
+        body: {
+          "issue": [
+            {
+              "number": 456,
+              "labels": {
+                "author": "Liu",
+                "version": "2.1",
+                "backport": [
+                  "2.0",
+                  "1.3"
+                ],
+                "category": {
+                  "type": "API",
+                  "level": "enhancement"
+                },
+                "createdDate": "2023-02-01",
+                "comment": [ [ "Mike","LGTM" ],[ "John","Approved" ] ],
+                "views": 3333,
+                "priority": 1.50
+              }
+            }
+          ]
+        }
+
+  - do:
+      indices.refresh:
+        index: test_partial_flat_object_nested
+---
+# Delete Index when connection is teardown
+teardown:
+  - do:
+      indices.delete:
+        index: test_partial_flat_object_nested
+
+
+---
+# Verify that mappings under the catalog field did not expand
+# and no dynamic fields were created.
+"Mappings":
+  - skip:
+      version: " - 2.99.99"
+      reason: "flat_object is introduced in 3.0.0 in main branch"
+
+  - do:
+      indices.get_mapping:
+        index: test_partial_flat_object_nested
+  - is_true: test_partial_flat_object_nested.mappings
+  - match: { test_partial_flat_object_nested.mappings.properties.issue.properties.number.type: integer }
+  - match: { test_partial_flat_object_nested.mappings.properties.issue.properties.labels.type: flat_object }
+  # https://github.com/opensearch-project/OpenSearch/tree/main/rest-api-spec/src/main/resources/rest-api-spec/test#length
+  - length: { test_partial_flat_object_nested.mappings.properties.issue.properties: 2 }
+  - length: { test_partial_flat_object_nested.mappings.properties.issue.properties.labels: 1 }
+
+
+---
+"Supported queries":
+  - skip:
+      version: " - 2.99.99"
+      reason: "flat_object is introduced in 3.0.0 in main branch"
+
+
+  # Verify Document Count
+  - do:
+      search:
+        body: {
+          query: {
+            match_all: { }
+          }
+        }
+
+  - length: { hits.hits: 2 }
+
+  # Match Query with exact dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                match: { "issue.labels.version": "2.1" }
+              }
+            }
+          }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.0.labels.version: "2.1" }
+
+  # Match Query without exact dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                match: { "issue.labels": "2.1" }
+              }
+            }
+          }
+        }
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.0.labels.version: "2.1" }
+
+  # Term Query1 with exact dot path for date
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                term: { issue.labels.createdDate: "2023-01-01" }
+              }
+            } } }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.0.labels.createdDate: "2023-01-01" }
+
+  # Term Query1 without exact dot path for date
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                term: { issue.labels: "2023-01-01" }
+              } } }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.0.labels.createdDate: "2023-01-01" }
+
+  # Term Query2 with dot path for string
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                term: { "issue.labels.category.type": "API" }
+              } } }
+        }
+
+  - length: { hits.hits: 2 }
+  - match: { hits.hits.0._source.issue.0.labels.category.type: "API" }
+  - match: { hits.hits.1._source.issue.0.labels.category.type: "API" }
+
+  # Term Query2 without exact dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                term: { issue.labels: "API" }
+              } } }
+        }
+
+  - length: { hits.hits: 2 }
+  - match: { hits.hits.0._source.issue.0.labels.category.type: "API" }
+  - match: { hits.hits.1._source.issue.0.labels.category.type: "API" }
+
+  # Term Query3 with dot path for array
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                term: { issue.labels.backport: "1.9" }
+              } } }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.0.labels.backport: [ "2.0", "1.9" ] }
+
+  # Term Query3 without dot path for array
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                term: { issue.labels: "1.9" }
+              } } }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.0.labels.backport: [ "2.0", "1.9" ] }
+
+  # Term Query4 with  dot path for nested-array
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                term: { issue.labels.comment: "LGTM" }
+              } } }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.0.labels.comment: [ [ "Mike","LGTM" ],[ "John","Approved" ] ] }
+
+  # Term Query4 without dot path for nested-array
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                term: { issue.labels: "LGTM" } } }
+          }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.0.labels.comment: [ [ "Mike","LGTM" ],[ "John","Approved" ] ] }
+
+  # Terms Query without dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                terms: { issue.labels: [ "John","Mike" ] } } }
+          }
+        }
+
+  - length: { hits.hits: 2 }
+  - match: { hits.hits.0._source.issue.0.labels.comment: [ [ "Doe","Shipped" ],[ "John","Approved" ] ] }
+  - match: { hits.hits.1._source.issue.0.labels.comment: [ [ "Mike","LGTM" ],[ "John","Approved" ] ] }
+
+  # Terms Query with dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                terms: { issue.labels.comment: [ "John","Mike" ] } } }
+          }
+        }
+
+  - length: { hits.hits: 2 }
+  - match: { hits.hits.0._source.issue.0.labels.comment: [ [ "Doe","Shipped" ],[ "John","Approved" ] ] }
+  - match: { hits.hits.1._source.issue.0.labels.comment: [ [ "Mike","LGTM" ],[ "John","Approved" ] ] }
+
+  # Prefix Query with dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                "prefix": {
+                  "issue.labels.comment": {
+                    "value": "Mi"
+                  } } }
+            }
+          }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.0.labels.comment: [ [ "Mike","LGTM" ],[ "John","Approved" ] ] }
+
+  # Prefix Query without dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                "prefix": {
+                  "issue.labels": {
+                    "value": "Mi"
+                  }
+                }
+              } } }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.0.labels.comment: [ [ "Mike","LGTM" ],[ "John","Approved" ] ] }
+
+  # Range Query with dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                "range": {
+                  "issue.labels.version": {
+                    "gte": "2.1",
+                    "lte": "3.0"
+                  } } }
+            }
+          }
+        }
+
+  - length: { hits.hits: 2 }
+  - match: { hits.hits.0._source.issue.0.labels.version: "2.2" }
+  - match: { hits.hits.1._source.issue.0.labels.version: "2.1" }
+
+  # Range Query without dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                "range": {
+                  "issue.labels": {
+                    "gte": "2.1",
+                    "lte": "3.0"
+                  } } }
+            }
+          }
+        }
+
+  - length: { hits.hits: 2 }
+  - match: { hits.hits.0._source.issue.0.labels.version: "2.2" }
+  - match: { hits.hits.1._source.issue.0.labels.version: "2.1" }
+
+  # Range Query with integer input with dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                "range": {
+                  "issue.labels.views": {
+                    "gte": 3000,
+                    "lte": 4000
+                  } } }
+            }
+          }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.0.labels.views: 3333 }
+
+  # Range Query with integer input without dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                "range": {
+                  "issue.labels": {
+                    "gte": 3000,
+                    "lte": 4000
+                  } } }
+            }
+          }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.0.labels.views: 3333 }
+
+
+  # Range Query with double input with dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                "range": {
+                  "issue.labels.priority": {
+                    "gte": 4.1234,
+                    "lte": 5.1234
+                  } } }
+            }
+          }
+        }
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.0.labels.priority: 5.00 }
+
+  # Range Query with double input without dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                "range": {
+                  "issue.labels": {
+                    "gte": 4.1234,
+                    "lte": 5.1234
+                  } } }
+            }
+          }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.0.labels.priority: 5.00 }
+
+
+  # Exists Query with dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                "exists": {
+                  "field": issue.labels.priority
+                } } }
+          }
+        }
+
+  - length: { hits.hits: 2 }
+
+  # Exists Query with nested dot path, use the flat_object_field_name.last_key
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                "exists": {
+                  "field": issue.labels.type
+                } } }
+          }
+        }
+
+  - length: { hits.hits: 2 }
+
+  # Exists Query without dot path for the flat_object_field_name
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                "exists": {
+                  "field": issue.labels
+                } } }
+          }
+        }
+
+  - length: { hits.hits: 2 }
+
+  # Exists Query2 with dot path for one hit
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                "exists": {
+                  "field": issue.labels.author
+                } } }
+          }
+        }
+
+  - length: { hits.hits: 1 }
+
+  # Query_string Query without dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                "query_string": {
+                  "fields": [ "issue.labels" ],
+                  "query": "Doe OR Mike"
+                } } }
+          }
+        }
+
+  - length: { hits.hits: 2 }
+  - match: { hits.hits.0._source.issue.0.labels.comment: [ [ "Doe","Shipped" ],[ "John","Approved" ] ] }
+  - match: { hits.hits.1._source.issue.0.labels.comment: [ [ "Mike","LGTM" ],[ "John","Approved" ] ] }
+
+  # Query_string Query with dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                "query_string": {
+                  "fields": [ "issue.labels.comment" ],
+                  "query": "Doe OR Mike"
+                } } }
+          }
+        }
+
+  - length: { hits.hits: 2 }
+  - match: { hits.hits.0._source.issue.0.labels.comment: [ [ "Doe","Shipped" ],[ "John","Approved" ] ] }
+  - match: { hits.hits.1._source.issue.0.labels.comment: [ [ "Mike","LGTM" ],[ "John","Approved" ] ] }
+
+  # Simple_query_string Query without full dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                "simple_query_string": {
+                  "query": "Doe",
+                  "fields": [ "issue.labels" ]
+                } } }
+          }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.0.labels.comment: [ [ "Doe","Shipped" ],[ "John","Approved" ] ] }
+
+  # Simple_query_string Query with dot path.
+  - do:
+      search:
+        body: {
+          _source: true,
+          query: {
+            nested: {
+              path: "issue",
+              query: {
+                "simple_query_string": {
+                  "query": "Doe",
+                  "fields": [ "issue.labels.comment" ]
+                } } }
+          }
+        }
+
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._source.issue.0.labels.comment: [ [ "Doe","Shipped" ],[ "John","Approved" ] ] }
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/test/search/90_search_after.yml b/rest-api-spec/src/main/resources/rest-api-spec/test/search/90_search_after.yml
index 65c1527a68b96..55e1566656faf 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/test/search/90_search_after.yml
+++ b/rest-api-spec/src/main/resources/rest-api-spec/test/search/90_search_after.yml
@@ -160,6 +160,28 @@
   - match: {hits.hits.0._source.timestamp: "2019-10-21 00:30:04.828" }
   - match: {hits.hits.0.sort: [1571617804828] }
 
+  # search_after with the sort with missing
+  - do:
+      bulk:
+        refresh: true
+        index: test
+        body: |
+          {"index":{}}
+          {"timestamp": null}
+  - do:
+      search:
+        index: test
+        rest_total_hits_as_int: true
+        body:
+          "size": 5
+          "sort": [ { "timestamp": { "order": "asc", "missing": "_last" } } ]
+          search_after: [ "2021-10-21 08:30:04.828" ] # making it out of min/max so only missing value hit is qualified
+
+  - match: { hits.total: 3 }
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._index: test }
+  - match: { hits.hits.0._source.timestamp: null }
+
 ---
 "date_nanos":
   - skip:
@@ -276,3 +298,25 @@
   - match: {hits.hits.0._index: test }
   - match: {hits.hits.0._source.population: 15223372036854775800 }
   - match: {hits.hits.0.sort: [15223372036854775800] }
+
+  # search_after with the sort with missing
+  - do:
+      bulk:
+        refresh: true
+        index: test
+        body: |
+          {"index":{}}
+          {"population": null}
+  - do:
+      search:
+        index: test
+        rest_total_hits_as_int: true
+        body:
+          "size": 5
+          "sort": [ { "population": { "order": "asc", "missing": "_last" } } ]
+          search_after: [15223372036854775801] # making it out of min/max so only missing value hit is qualified
+
+  - match: { hits.total: 3 }
+  - length: { hits.hits: 1 }
+  - match: { hits.hits.0._index: test }
+  - match: { hits.hits.0._source.population: null }
diff --git a/server/build.gradle b/server/build.gradle
index ab67eabe76d0c..38bbf020d860b 100644
--- a/server/build.gradle
+++ b/server/build.gradle
@@ -46,7 +46,9 @@ publishing {
   }
 }
 
-archivesBaseName = 'opensearch'
+base {
+  archivesBaseName = 'opensearch'
+}
 
 sourceSets {
   main {
diff --git a/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationAllocationIT.java b/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationAllocationIT.java
index cbaf70c325a57..b6ea3a094f496 100644
--- a/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationAllocationIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationAllocationIT.java
@@ -233,24 +233,30 @@ private void verifyPerIndexPrimaryBalance() throws Exception {
             RoutingNodes nodes = currentState.getRoutingNodes();
             for (final Map.Entry<String, IndexRoutingTable> index : currentState.getRoutingTable().indicesRouting().entrySet()) {
                 final int totalPrimaryShards = index.getValue().primaryShardsActive();
-                final int avgPrimaryShardsPerNode = (int) Math.floor(totalPrimaryShards * 1f / currentState.getRoutingNodes().size());
+                final int lowerBoundPrimaryShardsPerNode = (int) Math.floor(totalPrimaryShards * 1f / currentState.getRoutingNodes().size())
+                    - 1;
+                final int upperBoundPrimaryShardsPerNode = (int) Math.ceil(totalPrimaryShards * 1f / currentState.getRoutingNodes().size())
+                    + 1;
                 for (RoutingNode node : nodes) {
                     final int primaryCount = node.shardsWithState(index.getKey(), STARTED)
                         .stream()
                         .filter(ShardRouting::primary)
                         .collect(Collectors.toList())
                         .size();
-                    if (primaryCount > avgPrimaryShardsPerNode) {
-                        logger.info(
-                            "--> Primary shard balance assertion failure for index {} on node {} {} <= {}",
-                            index.getKey(),
-                            node.node().getName(),
-                            primaryCount,
-                            avgPrimaryShardsPerNode
-                        );
-                    }
                     // Asserts value is within the variance threshold (-1/+1 of the average value).
-                    assertTrue(avgPrimaryShardsPerNode - 1 <= primaryCount && primaryCount <= avgPrimaryShardsPerNode + 1);
+                    assertTrue(
+                        "--> Primary balance assertion failure for index "
+                            + index
+                            + "on node "
+                            + node.node().getName()
+                            + " "
+                            + lowerBoundPrimaryShardsPerNode
+                            + " <= "
+                            + primaryCount
+                            + " (assigned) <= "
+                            + upperBoundPrimaryShardsPerNode,
+                        lowerBoundPrimaryShardsPerNode <= primaryCount && primaryCount <= upperBoundPrimaryShardsPerNode
+                    );
                 }
             }
         }, 60, TimeUnit.SECONDS);
diff --git a/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationClusterSettingIT.java b/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationClusterSettingIT.java
index 57578cdbfa8e8..c1326c1b50c9e 100644
--- a/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationClusterSettingIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationClusterSettingIT.java
@@ -15,16 +15,8 @@
 import org.opensearch.index.Index;
 import org.opensearch.index.IndexModule;
 import org.opensearch.indices.IndicesService;
-import org.opensearch.indices.SystemIndexDescriptor;
 import org.opensearch.indices.replication.common.ReplicationType;
-import org.opensearch.plugins.Plugin;
-import org.opensearch.plugins.SystemIndexPlugin;
 import org.opensearch.test.OpenSearchIntegTestCase;
-import org.opensearch.test.transport.MockTransportService;
-
-import java.util.Collection;
-import java.util.Collections;
-import java.util.Arrays;
 
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_REPLICATION_TYPE;
 import static org.opensearch.indices.IndicesService.CLUSTER_SETTING_REPLICATION_TYPE;
@@ -60,40 +52,6 @@ protected Settings nodeSettings(int nodeOrdinal) {
             .build();
     }
 
-    public static class TestPlugin extends Plugin implements SystemIndexPlugin {
-        @Override
-        public Collection<SystemIndexDescriptor> getSystemIndexDescriptors(Settings settings) {
-            return Collections.singletonList(
-                new SystemIndexDescriptor(SYSTEM_INDEX_NAME, "System index for [" + getTestClass().getName() + ']')
-            );
-        }
-    }
-
-    @Override
-    protected Collection<Class<? extends Plugin>> nodePlugins() {
-        return Arrays.asList(SegmentReplicationClusterSettingIT.TestPlugin.class, MockTransportService.TestPlugin.class);
-    }
-
-    public void testSystemIndexWithSegmentReplicationClusterSetting() throws Exception {
-
-        // Starting two nodes with primary and replica shards respectively.
-        final String primaryNode = internalCluster().startNode();
-        createIndex(SYSTEM_INDEX_NAME);
-        ensureYellowAndNoInitializingShards(SYSTEM_INDEX_NAME);
-        final String replicaNode = internalCluster().startNode();
-        ensureGreen(SYSTEM_INDEX_NAME);
-        final GetSettingsResponse response = client().admin()
-            .indices()
-            .getSettings(new GetSettingsRequest().indices(SYSTEM_INDEX_NAME).includeDefaults(true))
-            .actionGet();
-        assertEquals(response.getSetting(SYSTEM_INDEX_NAME, SETTING_REPLICATION_TYPE), ReplicationType.DOCUMENT.toString());
-
-        // Verify index setting isSegRepEnabled is false.
-        Index index = resolveIndex(SYSTEM_INDEX_NAME);
-        IndicesService indicesService = internalCluster().getInstance(IndicesService.class, primaryNode);
-        assertEquals(indicesService.indexService(index).getIndexSettings().isSegRepEnabled(), false);
-    }
-
     public void testIndexReplicationSettingOverridesSegRepClusterSetting() throws Exception {
         Settings settings = Settings.builder().put(CLUSTER_SETTING_REPLICATION_TYPE, ReplicationType.SEGMENT).build();
         final String ANOTHER_INDEX = "test-index";
@@ -165,28 +123,4 @@ public void testIndexReplicationSettingOverridesDocRepClusterSetting() throws Ex
         assertEquals(indicesService.indexService(anotherIndex).getIndexSettings().isSegRepEnabled(), false);
     }
 
-    public void testHiddenIndicesWithReplicationStrategyClusterSetting() throws Exception {
-        final String primaryNode = internalCluster().startNode();
-        final String replicaNode = internalCluster().startNode();
-        prepareCreate(
-            INDEX_NAME,
-            Settings.builder()
-                // we want to set index as hidden
-                .put("index.hidden", true)
-        ).get();
-        ensureGreen(INDEX_NAME);
-
-        // Verify that document replication strategy is used for hidden indices.
-        final GetSettingsResponse response = client().admin()
-            .indices()
-            .getSettings(new GetSettingsRequest().indices(INDEX_NAME).includeDefaults(true))
-            .actionGet();
-        assertEquals(response.getSetting(INDEX_NAME, SETTING_REPLICATION_TYPE), ReplicationType.DOCUMENT.toString());
-
-        // Verify index setting isSegRepEnabled.
-        Index index = resolveIndex(INDEX_NAME);
-        IndicesService indicesService = internalCluster().getInstance(IndicesService.class, primaryNode);
-        assertEquals(indicesService.indexService(index).getIndexSettings().isSegRepEnabled(), false);
-    }
-
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationIT.java b/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationIT.java
index ce5e0989b622f..ac57c78d20b73 100644
--- a/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationIT.java
@@ -435,6 +435,7 @@ public void testNodeDropWithOngoingReplication() throws Exception {
         refresh(INDEX_NAME);
         blockFileCopy.countDown();
         internalCluster().stopRandomNode(InternalTestCluster.nameFilter(primaryNode));
+        ensureYellow(INDEX_NAME);
         assertBusy(() -> { assertDocCounts(docCount, replicaNode); });
         state = client().admin().cluster().prepareState().execute().actionGet().getState();
         // replica now promoted as primary should have same allocation id
@@ -732,6 +733,7 @@ public void testDropPrimaryDuringReplication() throws Exception {
             // start another replica.
             dataNodes.add(internalCluster().startDataOnlyNode());
             ensureGreen(INDEX_NAME);
+            waitForSearchableDocs(initialDocCount, dataNodes);
 
             // index another doc and refresh - without this the new replica won't catch up.
             String docId = String.valueOf(initialDocCount + 1);
@@ -799,6 +801,7 @@ public void testReplicaHasDiffFilesThanPrimary() throws Exception {
     public void testPressureServiceStats() throws Exception {
         final String primaryNode = internalCluster().startDataOnlyNode();
         createIndex(INDEX_NAME);
+        ensureYellow(INDEX_NAME);
         final String replicaNode = internalCluster().startDataOnlyNode();
         ensureGreen(INDEX_NAME);
 
diff --git a/server/src/internalClusterTest/java/org/opensearch/remotestore/CreateRemoteIndexIT.java b/server/src/internalClusterTest/java/org/opensearch/remotestore/CreateRemoteIndexIT.java
index 46966e289e75e..fda344acad166 100644
--- a/server/src/internalClusterTest/java/org/opensearch/remotestore/CreateRemoteIndexIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/remotestore/CreateRemoteIndexIT.java
@@ -12,24 +12,15 @@
 import org.junit.Before;
 import org.opensearch.action.admin.indices.get.GetIndexRequest;
 import org.opensearch.action.admin.indices.get.GetIndexResponse;
-import org.opensearch.action.admin.indices.settings.get.GetSettingsRequest;
-import org.opensearch.action.admin.indices.settings.get.GetSettingsResponse;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.common.util.FeatureFlags;
-import org.opensearch.indices.SystemIndexDescriptor;
 import org.opensearch.index.IndexSettings;
 import org.opensearch.indices.replication.common.ReplicationType;
-import org.opensearch.plugins.Plugin;
-import org.opensearch.plugins.SystemIndexPlugin;
 import org.opensearch.test.FeatureFlagSetter;
 import org.opensearch.test.OpenSearchIntegTestCase;
 
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.Collections;
-
 import static org.hamcrest.Matchers.containsString;
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_REMOTE_STORE_ENABLED;
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_REMOTE_STORE_REPOSITORY;
@@ -68,20 +59,6 @@ protected Settings nodeSettings(int nodeOriginal) {
         return builder.build();
     }
 
-    public static class TestPlugin extends Plugin implements SystemIndexPlugin {
-        @Override
-        public Collection<SystemIndexDescriptor> getSystemIndexDescriptors(Settings settings) {
-            return Collections.singletonList(
-                new SystemIndexDescriptor(SYSTEM_INDEX_NAME, "System index for [" + getTestClass().getName() + ']')
-            );
-        }
-    }
-
-    @Override
-    protected Collection<Class<? extends Plugin>> nodePlugins() {
-        return Arrays.asList(CreateRemoteIndexIT.TestPlugin.class);
-    }
-
     @Override
     protected Settings featureFlagSettings() {
         return Settings.builder().put(super.featureFlagSettings()).put(FeatureFlags.REMOTE_STORE, "true").build();
@@ -130,35 +107,6 @@ public void testDefaultRemoteStoreNoUserOverride() throws Exception {
         );
     }
 
-    private static final String SYSTEM_INDEX_NAME = ".test-system-index";
-
-    public void testSystemIndexWithRemoteStoreClusterSetting() throws Exception {
-        createIndex(SYSTEM_INDEX_NAME);
-        ensureGreen(SYSTEM_INDEX_NAME);
-        final GetSettingsResponse response = client().admin()
-            .indices()
-            .getSettings(new GetSettingsRequest().indices(SYSTEM_INDEX_NAME).includeDefaults(true))
-            .actionGet();
-        // Verify that Document replication strategy is used
-        assertEquals(response.getSetting(SYSTEM_INDEX_NAME, SETTING_REPLICATION_TYPE), ReplicationType.DOCUMENT.toString());
-        assertEquals(response.getSetting(SYSTEM_INDEX_NAME, SETTING_REMOTE_STORE_ENABLED), "false");
-    }
-
-    public void testSystemIndexWithRemoteStoreIndexSettings() throws Exception {
-        prepareCreate(
-            SYSTEM_INDEX_NAME,
-            Settings.builder().put(SETTING_REPLICATION_TYPE, ReplicationType.SEGMENT).put(SETTING_REMOTE_STORE_ENABLED, true)
-        ).get();
-        ensureGreen(SYSTEM_INDEX_NAME);
-        final GetSettingsResponse response = client().admin()
-            .indices()
-            .getSettings(new GetSettingsRequest().indices(SYSTEM_INDEX_NAME).includeDefaults(true))
-            .actionGet();
-        // Verify that Document replication strategy is used
-        assertEquals(response.getSetting(SYSTEM_INDEX_NAME, SETTING_REPLICATION_TYPE), ReplicationType.DOCUMENT.toString());
-        assertEquals(response.getSetting(SYSTEM_INDEX_NAME, SETTING_REMOTE_STORE_ENABLED), "false");
-    }
-
     public void testRemoteStoreDisabledByUser() throws Exception {
         Settings settings = Settings.builder()
             .put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, 1)
diff --git a/server/src/internalClusterTest/java/org/opensearch/remotestore/PrimaryTermValidationIT.java b/server/src/internalClusterTest/java/org/opensearch/remotestore/PrimaryTermValidationIT.java
new file mode 100644
index 0000000000000..6691da81f057d
--- /dev/null
+++ b/server/src/internalClusterTest/java/org/opensearch/remotestore/PrimaryTermValidationIT.java
@@ -0,0 +1,166 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.remotestore;
+
+import org.opensearch.action.admin.cluster.health.ClusterHealthRequest;
+import org.opensearch.action.admin.cluster.health.ClusterHealthResponse;
+import org.opensearch.action.admin.cluster.node.info.NodesInfoResponse;
+import org.opensearch.action.admin.indices.refresh.RefreshResponse;
+import org.opensearch.action.index.IndexResponse;
+import org.opensearch.action.support.IndicesOptions;
+import org.opensearch.cluster.coordination.FollowersChecker;
+import org.opensearch.cluster.coordination.LeaderChecker;
+import org.opensearch.cluster.health.ClusterHealthStatus;
+import org.opensearch.cluster.health.ClusterIndexHealth;
+import org.opensearch.common.UUIDs;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.xcontent.XContentType;
+import org.opensearch.index.shard.ShardNotFoundException;
+import org.opensearch.plugins.Plugin;
+import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.disruption.NetworkDisruption;
+import org.opensearch.test.transport.MockTransportService;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import static org.hamcrest.Matchers.equalTo;
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertNoFailures;
+
+@OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.TEST, numDataNodes = 0)
+
+public class PrimaryTermValidationIT extends RemoteStoreBaseIntegTestCase {
+
+    private static final String INDEX_NAME = "remote-store-test-idx-1";
+
+    @Override
+    protected Collection<Class<? extends Plugin>> nodePlugins() {
+        return Arrays.asList(MockTransportService.TestPlugin.class);
+    }
+
+    public void testPrimaryTermValidation() throws Exception {
+        // Follower checker interval is lower compared to leader checker so that the cluster manager can remove the node
+        // with network partition faster. The follower check retry count is also kept 1.
+        Settings clusterSettings = Settings.builder()
+            .put(LeaderChecker.LEADER_CHECK_TIMEOUT_SETTING.getKey(), "1s")
+            .put(LeaderChecker.LEADER_CHECK_INTERVAL_SETTING.getKey(), "20s")
+            .put(LeaderChecker.LEADER_CHECK_RETRY_COUNT_SETTING.getKey(), 4)
+            .put(FollowersChecker.FOLLOWER_CHECK_TIMEOUT_SETTING.getKey(), "1s")
+            .put(FollowersChecker.FOLLOWER_CHECK_INTERVAL_SETTING.getKey(), "1s")
+            .put(FollowersChecker.FOLLOWER_CHECK_RETRY_COUNT_SETTING.getKey(), 1)
+            .build();
+        internalCluster().startClusterManagerOnlyNode(clusterSettings);
+
+        // Create repository
+        absolutePath = randomRepoPath().toAbsolutePath();
+        assertAcked(
+            clusterAdmin().preparePutRepository(REPOSITORY_NAME).setType("fs").setSettings(Settings.builder().put("location", absolutePath))
+        );
+
+        // Start data nodes and create index
+        internalCluster().startDataOnlyNodes(2, clusterSettings);
+        createIndex(INDEX_NAME, remoteTranslogIndexSettings(1));
+        ensureYellowAndNoInitializingShards(INDEX_NAME);
+        ensureGreen(INDEX_NAME);
+
+        // Get the names of nodes to create network disruption
+        String primaryNode = primaryNodeName(INDEX_NAME);
+        String replicaNode = replicaNodeName(INDEX_NAME);
+        String clusterManagerNode = internalCluster().getClusterManagerName();
+        logger.info("Node names : clusterManager={} primary={} replica={}", clusterManagerNode, primaryNode, replicaNode);
+
+        // Index some docs and validate that both primary and replica node has it. Refresh is triggered to trigger segment replication
+        // to ensure replica is also upto date.
+        int numOfDocs = randomIntBetween(5, 10);
+        for (int i = 0; i < numOfDocs; i++) {
+            indexSameDoc(clusterManagerNode, INDEX_NAME);
+        }
+        refresh(INDEX_NAME);
+        assertBusy(
+            () -> assertHitCount(client(primaryNode).prepareSearch(INDEX_NAME).setSize(0).setPreference("_only_local").get(), numOfDocs)
+        );
+        assertBusy(
+            () -> assertHitCount(client(replicaNode).prepareSearch(INDEX_NAME).setSize(0).setPreference("_only_local").get(), numOfDocs)
+        );
+
+        // Start network disruption - primary node will be isolated
+        Set<String> nodesInOneSide = Stream.of(clusterManagerNode, replicaNode).collect(Collectors.toCollection(HashSet::new));
+        Set<String> nodesInOtherSide = Stream.of(primaryNode).collect(Collectors.toCollection(HashSet::new));
+        NetworkDisruption networkDisruption = new NetworkDisruption(
+            new NetworkDisruption.TwoPartitions(nodesInOneSide, nodesInOtherSide),
+            NetworkDisruption.DISCONNECT
+        );
+        internalCluster().setDisruptionScheme(networkDisruption);
+        logger.info("--> network disruption is started");
+        networkDisruption.startDisrupting();
+
+        // Ensure the node which is partitioned is removed from the cluster
+        assertBusy(() -> {
+            NodesInfoResponse response = client(clusterManagerNode).admin().cluster().prepareNodesInfo().get();
+            assertThat(response.getNodes().size(), equalTo(2));
+        });
+
+        // Ensure that the cluster manager has latest information about the index
+        assertBusy(() -> {
+            ClusterHealthResponse clusterHealthResponse = client(clusterManagerNode).admin()
+                .cluster()
+                .health(new ClusterHealthRequest())
+                .actionGet(TimeValue.timeValueSeconds(1));
+            assertTrue(clusterHealthResponse.getIndices().containsKey(INDEX_NAME));
+            ClusterIndexHealth clusterIndexHealth = clusterHealthResponse.getIndices().get(INDEX_NAME);
+            assertEquals(ClusterHealthStatus.YELLOW, clusterHealthResponse.getStatus());
+            assertEquals(1, clusterIndexHealth.getNumberOfShards());
+            assertEquals(1, clusterIndexHealth.getActiveShards());
+            assertEquals(1, clusterIndexHealth.getUnassignedShards());
+            assertEquals(1, clusterIndexHealth.getUnassignedShards());
+            assertEquals(1, clusterIndexHealth.getActivePrimaryShards());
+            assertEquals(ClusterHealthStatus.YELLOW, clusterIndexHealth.getStatus());
+        });
+
+        // Index data to the newly promoted primary
+        indexSameDoc(clusterManagerNode, INDEX_NAME);
+        RefreshResponse refreshResponse = client(clusterManagerNode).admin()
+            .indices()
+            .prepareRefresh(INDEX_NAME)
+            .setIndicesOptions(IndicesOptions.STRICT_EXPAND_OPEN_HIDDEN_FORBID_CLOSED)
+            .execute()
+            .actionGet();
+        assertNoFailures(refreshResponse);
+        assertEquals(1, refreshResponse.getSuccessfulShards());
+        assertHitCount(client(replicaNode).prepareSearch(INDEX_NAME).setSize(0).setPreference("_only_local").get(), numOfDocs + 1);
+
+        // At this point we stop the disruption. Since the follower checker has already failed and cluster manager has removed the node
+        // from cluster, failed node needs to start discovery process by leader checker call. We stop the disruption to allow the failed
+        // node to
+        // communicate with the other node which it assumes has replica.
+        networkDisruption.stopDisrupting();
+
+        // When the index call is made to the stale primary, it makes the primary term validation call to the other node (which
+        // it assumes has the replica node). At this moment, the stale primary realises that it is no more the primary and the caller
+        // received the following exception.
+        ShardNotFoundException exception = assertThrows(ShardNotFoundException.class, () -> indexSameDoc(primaryNode, INDEX_NAME));
+        assertTrue(exception.getMessage().contains("no such shard"));
+        ensureStableCluster(3);
+        ensureGreen(INDEX_NAME);
+    }
+
+    private IndexResponse indexSameDoc(String nodeName, String indexName) {
+        return client(nodeName).prepareIndex(indexName)
+            .setId(UUIDs.randomBase64UUID())
+            .setSource("{\"foo\" : \"bar\"}", XContentType.JSON)
+            .get();
+    }
+}
diff --git a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreBaseIntegTestCase.java b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreBaseIntegTestCase.java
index d226d0d757638..2b3fcadfc645e 100644
--- a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreBaseIntegTestCase.java
+++ b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreBaseIntegTestCase.java
@@ -9,12 +9,12 @@
 package org.opensearch.remotestore;
 
 import org.junit.After;
-import org.junit.Before;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.IndexModule;
 import org.opensearch.index.IndexSettings;
+import org.opensearch.index.mapper.MapperService;
 import org.opensearch.indices.replication.common.ReplicationType;
 import org.opensearch.test.OpenSearchIntegTestCase;
 
@@ -74,6 +74,13 @@ protected Settings remoteStoreIndexSettings(int numberOfReplicas) {
         return remoteStoreIndexSettings(numberOfReplicas, 1);
     }
 
+    protected Settings remoteStoreIndexSettings(int numberOfReplicas, long totalFieldLimit) {
+        return Settings.builder()
+            .put(remoteStoreIndexSettings(numberOfReplicas))
+            .put(MapperService.INDEX_MAPPING_TOTAL_FIELDS_LIMIT_SETTING.getKey(), totalFieldLimit)
+            .build();
+    }
+
     protected Settings remoteTranslogIndexSettings(int numberOfReplicas, int numberOfShards) {
         return Settings.builder()
             .put(remoteStoreIndexSettings(numberOfReplicas, numberOfShards))
@@ -92,8 +99,7 @@ protected void putRepository(Path path) {
         );
     }
 
-    @Before
-    public void setup() {
+    protected void setupRepo() {
         internalCluster().startClusterManagerOnlyNode();
         absolutePath = randomRepoPath().toAbsolutePath();
         assertAcked(
diff --git a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreIT.java b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreIT.java
index 70a41d74a57c5..85208a33cc9f5 100644
--- a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreIT.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.remotestore;
 
+import org.junit.Before;
 import org.opensearch.action.admin.cluster.remotestore.restore.RestoreRemoteStoreRequest;
 import org.opensearch.action.admin.indices.delete.DeleteIndexRequest;
 import org.opensearch.action.admin.indices.recovery.RecoveryResponse;
@@ -17,6 +18,7 @@
 import org.opensearch.cluster.routing.RecoverySource;
 import org.opensearch.common.UUIDs;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.index.shard.RemoteStoreRefreshListener;
 import org.opensearch.indices.recovery.RecoveryState;
 import org.opensearch.plugins.Plugin;
 import org.opensearch.test.InternalTestCluster;
@@ -50,6 +52,11 @@ protected Collection<Class<? extends Plugin>> nodePlugins() {
         return Arrays.asList(MockTransportService.TestPlugin.class);
     }
 
+    @Before
+    public void setup() {
+        setupRepo();
+    }
+
     @Override
     public Settings indexSettings() {
         return remoteStoreIndexSettings(0);
@@ -277,4 +284,44 @@ public void testRemoteSegmentCleanup() throws Exception {
     public void testRemoteTranslogCleanup() throws Exception {
         verifyRemoteStoreCleanup(true);
     }
+
+    @AwaitsFix(bugUrl = "https://github.com/opensearch-project/OpenSearch/issues/8504")
+    public void testStaleCommitDeletionWithInvokeFlush() throws Exception {
+        internalCluster().startDataOnlyNodes(3);
+        createIndex(INDEX_NAME, remoteStoreIndexSettings(1, 10000l));
+        int numberOfIterations = randomIntBetween(5, 15);
+        indexData(numberOfIterations, true);
+        String indexUUID = client().admin()
+            .indices()
+            .prepareGetSettings(INDEX_NAME)
+            .get()
+            .getSetting(INDEX_NAME, IndexMetadata.SETTING_INDEX_UUID);
+        Path indexPath = Path.of(String.valueOf(absolutePath), indexUUID, "/0/segments/metadata");
+        // Delete is async.
+        assertBusy(() -> {
+            int actualFileCount = getFileCount(indexPath);
+            if (numberOfIterations <= RemoteStoreRefreshListener.LAST_N_METADATA_FILES_TO_KEEP) {
+                assertEquals(numberOfIterations, actualFileCount);
+            } else {
+                // As delete is async its possible that the file gets created before the deletion or after
+                // deletion.
+                assertTrue(actualFileCount >= 10 || actualFileCount <= 11);
+            }
+        }, 30, TimeUnit.SECONDS);
+    }
+
+    @AwaitsFix(bugUrl = "https://github.com/opensearch-project/OpenSearch/issues/8504")
+    public void testStaleCommitDeletionWithoutInvokeFlush() throws Exception {
+        internalCluster().startDataOnlyNodes(3);
+        createIndex(INDEX_NAME, remoteStoreIndexSettings(1, 10000l));
+        int numberOfIterations = randomIntBetween(5, 15);
+        indexData(numberOfIterations, false);
+        String indexUUID = client().admin()
+            .indices()
+            .prepareGetSettings(INDEX_NAME)
+            .get()
+            .getSetting(INDEX_NAME, IndexMetadata.SETTING_INDEX_UUID);
+        Path indexPath = Path.of(String.valueOf(absolutePath), indexUUID, "/0/segments/metadata");
+        assertEquals(numberOfIterations, getFileCount(indexPath));
+    }
 }
diff --git a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreStatsIT.java b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreStatsIT.java
index 0ea87d106c14e..0e4774c1f3454 100644
--- a/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreStatsIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/remotestore/RemoteStoreStatsIT.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.remotestore;
 
+import org.junit.Before;
 import org.opensearch.action.admin.cluster.remotestore.stats.RemoteStoreStats;
 import org.opensearch.action.admin.cluster.remotestore.stats.RemoteStoreStatsRequestBuilder;
 import org.opensearch.action.admin.cluster.remotestore.stats.RemoteStoreStatsResponse;
@@ -28,6 +29,11 @@ public class RemoteStoreStatsIT extends RemoteStoreBaseIntegTestCase {
 
     private static final String INDEX_NAME = "remote-store-test-idx-1";
 
+    @Before
+    public void setup() {
+        setupRepo();
+    }
+
     public void testStatsResponseFromAllNodes() {
 
         // Step 1 - We create cluster, create an index, and then index documents into. We also do multiple refreshes/flushes
diff --git a/server/src/internalClusterTest/java/org/opensearch/remotestore/ReplicaToPrimaryPromotionIT.java b/server/src/internalClusterTest/java/org/opensearch/remotestore/ReplicaToPrimaryPromotionIT.java
index 712747f7479ae..0f3e041dd429a 100644
--- a/server/src/internalClusterTest/java/org/opensearch/remotestore/ReplicaToPrimaryPromotionIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/remotestore/ReplicaToPrimaryPromotionIT.java
@@ -9,6 +9,7 @@
 package org.opensearch.remotestore;
 
 import com.carrotsearch.randomizedtesting.RandomizedTest;
+import org.junit.Before;
 import org.opensearch.action.admin.indices.close.CloseIndexResponse;
 import org.opensearch.cluster.ClusterState;
 import org.opensearch.cluster.metadata.IndexMetadata;
@@ -31,6 +32,11 @@
 public class ReplicaToPrimaryPromotionIT extends RemoteStoreBaseIntegTestCase {
     private int shard_count = 5;
 
+    @Before
+    public void setup() {
+        setupRepo();
+    }
+
     @Override
     public Settings indexSettings() {
         return Settings.builder()
diff --git a/server/src/internalClusterTest/java/org/opensearch/remotestore/SegmentReplicationUsingRemoteStoreIT.java b/server/src/internalClusterTest/java/org/opensearch/remotestore/SegmentReplicationUsingRemoteStoreIT.java
index 01fb91f83aa02..d39b30ada5ef7 100644
--- a/server/src/internalClusterTest/java/org/opensearch/remotestore/SegmentReplicationUsingRemoteStoreIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/remotestore/SegmentReplicationUsingRemoteStoreIT.java
@@ -64,7 +64,6 @@ public void teardown() {
         assertAcked(clusterAdmin().prepareDeleteRepository(REPOSITORY_NAME));
     }
 
-    @AwaitsFix(bugUrl = "https://github.com/opensearch-project/OpenSearch/issues/7592")
     @Override
     public void testPressureServiceStats() throws Exception {
         super.testPressureServiceStats();
diff --git a/server/src/internalClusterTest/java/org/opensearch/snapshots/CloneSnapshotIT.java b/server/src/internalClusterTest/java/org/opensearch/snapshots/CloneSnapshotIT.java
index 5441dae9703ce..ce92a15026b70 100644
--- a/server/src/internalClusterTest/java/org/opensearch/snapshots/CloneSnapshotIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/snapshots/CloneSnapshotIT.java
@@ -38,11 +38,15 @@
 import org.opensearch.action.support.master.AcknowledgedResponse;
 import org.opensearch.client.Client;
 import org.opensearch.cluster.SnapshotsInProgress;
+import org.opensearch.cluster.metadata.RepositoryMetadata;
+import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.IndexNotFoundException;
 import org.opensearch.repositories.RepositoriesService;
 import org.opensearch.repositories.RepositoryData;
 import org.opensearch.snapshots.mockstore.MockRepository;
+import org.opensearch.test.FeatureFlagSetter;
 import org.opensearch.test.OpenSearchIntegTestCase;
 
 import java.util.ArrayList;
@@ -64,6 +68,7 @@
 import org.opensearch.repositories.blobstore.BlobStoreRepository;
 
 import java.nio.file.Path;
+import java.util.concurrent.ExecutionException;
 
 import static org.hamcrest.Matchers.hasSize;
 import static org.hamcrest.Matchers.is;
@@ -153,6 +158,162 @@ public void testCloneSnapshotIndex() throws Exception {
         assertEquals(status1.getStats().getTotalSize(), status2.getStats().getTotalSize());
     }
 
+    public void testCloneShallowSnapshotIndex() throws Exception {
+        disableRepoConsistencyCheck("This test uses remote store repository");
+        FeatureFlagSetter.set(FeatureFlags.REMOTE_STORE);
+        internalCluster().startClusterManagerOnlyNode();
+        internalCluster().startDataOnlyNode();
+
+        final String snapshotRepoName = "snapshot-repo-name";
+        final Path snapshotRepoPath = randomRepoPath();
+        createRepository(snapshotRepoName, "fs", snapshotRepoPath);
+
+        final String shallowSnapshotRepoName = "shallow-snapshot-repo-name";
+        final Path shallowSnapshotRepoPath = randomRepoPath();
+        createRepository(shallowSnapshotRepoName, "fs", snapshotRepoSettingsForShallowCopy(shallowSnapshotRepoPath));
+
+        final Path remoteStoreRepoPath = randomRepoPath();
+        final String remoteStoreRepoName = "remote-store-repo-name";
+        createRepository(remoteStoreRepoName, "fs", remoteStoreRepoPath);
+
+        final String indexName = "index-1";
+        createIndexWithRandomDocs(indexName, randomIntBetween(5, 10));
+
+        final String remoteStoreEnabledIndexName = "remote-index-1";
+        final Settings remoteStoreEnabledIndexSettings = getRemoteStoreBackedIndexSettings(remoteStoreRepoName);
+        createIndex(remoteStoreEnabledIndexName, remoteStoreEnabledIndexSettings);
+        indexRandomDocs(remoteStoreEnabledIndexName, randomIntBetween(5, 10));
+
+        final String snapshot = "snapshot";
+        createFullSnapshot(snapshotRepoName, snapshot);
+        assert (getLockFilesInRemoteStore(remoteStoreEnabledIndexName, remoteStoreRepoName).length == 0);
+
+        indexRandomDocs(indexName, randomIntBetween(20, 100));
+
+        final String shallowSnapshot = "shallow-snapshot";
+        createFullSnapshot(shallowSnapshotRepoName, shallowSnapshot);
+        assert (getLockFilesInRemoteStore(remoteStoreEnabledIndexName, remoteStoreRepoName).length == 1);
+
+        if (randomBoolean()) {
+            assertAcked(admin().indices().prepareDelete(indexName));
+        }
+
+        final String sourceSnapshot = shallowSnapshot;
+        final String targetSnapshot = "target-snapshot";
+        assertAcked(startClone(shallowSnapshotRepoName, sourceSnapshot, targetSnapshot, indexName, remoteStoreEnabledIndexName).get());
+        logger.info("Lock files count: {}", getLockFilesInRemoteStore(remoteStoreEnabledIndexName, remoteStoreRepoName).length);
+        assert (getLockFilesInRemoteStore(remoteStoreEnabledIndexName, remoteStoreRepoName).length == 2);
+    }
+
+    public void testShallowCloneNameAvailability() throws Exception {
+        disableRepoConsistencyCheck("This test uses remote store repository");
+        FeatureFlagSetter.set(FeatureFlags.REMOTE_STORE);
+        internalCluster().startClusterManagerOnlyNode(LARGE_SNAPSHOT_POOL_SETTINGS);
+        internalCluster().startDataOnlyNode();
+
+        final String shallowSnapshotRepoName = "shallow-snapshot-repo-name";
+        final Path shallowSnapshotRepoPath = randomRepoPath();
+        createRepository(shallowSnapshotRepoName, "fs", snapshotRepoSettingsForShallowCopy(shallowSnapshotRepoPath));
+
+        final Path remoteStoreRepoPath = randomRepoPath();
+        final String remoteStoreRepoName = "remote-store-repo-name";
+        createRepository(remoteStoreRepoName, "fs", remoteStoreRepoPath);
+
+        final String indexName = "index-1";
+        createIndexWithRandomDocs(indexName, randomIntBetween(5, 10));
+
+        final String remoteStoreEnabledIndexName = "remote-index-1";
+        final Settings remoteStoreEnabledIndexSettings = getRemoteStoreBackedIndexSettings(remoteStoreRepoName);
+        createIndex(remoteStoreEnabledIndexName, remoteStoreEnabledIndexSettings);
+        indexRandomDocs(remoteStoreEnabledIndexName, randomIntBetween(5, 10));
+
+        final String shallowSnapshot1 = "snapshot1";
+        createFullSnapshot(shallowSnapshotRepoName, shallowSnapshot1);
+
+        final String shallowSnapshot2 = "snapshot2";
+        createFullSnapshot(shallowSnapshotRepoName, shallowSnapshot2);
+
+        ExecutionException ex = expectThrows(
+            ExecutionException.class,
+            () -> startClone(shallowSnapshotRepoName, shallowSnapshot1, shallowSnapshot2, indexName, remoteStoreEnabledIndexName).get()
+        );
+        assertThat(ex.getMessage(), containsString("snapshot with the same name already exists"));
+    }
+
+    public void testCloneAfterRepoShallowSettingEnabled() throws Exception {
+        disableRepoConsistencyCheck("This test uses remote store repository");
+        FeatureFlagSetter.set(FeatureFlags.REMOTE_STORE);
+        internalCluster().startClusterManagerOnlyNode();
+        internalCluster().startDataOnlyNode();
+
+        final String snapshotRepoName = "snapshot-repo-name";
+        final Path snapshotRepoPath = randomRepoPath();
+        createRepository(snapshotRepoName, "fs", snapshotRepoPath);
+
+        final Path remoteStoreRepoPath = randomRepoPath();
+        final String remoteStoreRepoName = "remote-store-repo-name";
+        createRepository(remoteStoreRepoName, "fs", remoteStoreRepoPath);
+
+        final String indexName = "index-1";
+        createIndexWithRandomDocs(indexName, randomIntBetween(5, 10));
+
+        final String remoteStoreEnabledIndexName = "remote-index-1";
+        final Settings remoteStoreEnabledIndexSettings = getRemoteStoreBackedIndexSettings(remoteStoreRepoName);
+        createIndex(remoteStoreEnabledIndexName, remoteStoreEnabledIndexSettings);
+        indexRandomDocs(remoteStoreEnabledIndexName, randomIntBetween(5, 10));
+
+        final String snapshot = "snapshot";
+        createFullSnapshot(snapshotRepoName, snapshot);
+        assertEquals(getSnapshot(snapshotRepoName, snapshot).state(), SnapshotState.SUCCESS);
+
+        // Updating the snapshot repository flag to enable shallow snapshots
+        createRepository(snapshotRepoName, "fs", snapshotRepoSettingsForShallowCopy(snapshotRepoPath));
+        RepositoryMetadata updatedRepositoryMetadata = clusterAdmin().prepareGetRepositories(snapshotRepoName).get().repositories().get(0);
+        assertTrue(updatedRepositoryMetadata.settings().getAsBoolean(BlobStoreRepository.REMOTE_STORE_INDEX_SHALLOW_COPY.getKey(), false));
+
+        final String targetSnapshot = "target-snapshot";
+        assertAcked(startClone(snapshotRepoName, snapshot, targetSnapshot, indexName, remoteStoreEnabledIndexName).get());
+        assert (getLockFilesInRemoteStore(remoteStoreEnabledIndexName, remoteStoreRepoName).length == 0);
+        assertEquals(getSnapshot(snapshotRepoName, targetSnapshot).isRemoteStoreIndexShallowCopyEnabled(), false);
+    }
+
+    public void testCloneAfterRepoShallowSettingDisabled() throws Exception {
+        disableRepoConsistencyCheck("This test uses remote store repository");
+        FeatureFlagSetter.set(FeatureFlags.REMOTE_STORE);
+        internalCluster().startClusterManagerOnlyNode();
+        internalCluster().startDataOnlyNode();
+
+        final String snapshotRepoName = "snapshot-repo-name";
+        final Path snapshotRepoPath = randomRepoPath();
+        createRepository(snapshotRepoName, "fs", snapshotRepoSettingsForShallowCopy(snapshotRepoPath));
+
+        final Path remoteStoreRepoPath = randomRepoPath();
+        final String remoteStoreRepoName = "remote-store-repo-name";
+        createRepository(remoteStoreRepoName, "fs", remoteStoreRepoPath);
+
+        final String indexName = "index-1";
+        createIndexWithRandomDocs(indexName, randomIntBetween(5, 10));
+
+        final String remoteStoreEnabledIndexName = "remote-index-1";
+        final Settings remoteStoreEnabledIndexSettings = getRemoteStoreBackedIndexSettings(remoteStoreRepoName);
+        createIndex(remoteStoreEnabledIndexName, remoteStoreEnabledIndexSettings);
+        indexRandomDocs(remoteStoreEnabledIndexName, randomIntBetween(5, 10));
+
+        final String snapshot = "snapshot";
+        createFullSnapshot(snapshotRepoName, snapshot);
+        assertEquals(getSnapshot(snapshotRepoName, snapshot).state(), SnapshotState.SUCCESS);
+
+        // Updating the snapshot repository flag to enable shallow snapshots
+        createRepository(snapshotRepoName, "fs", snapshotRepoPath);
+        RepositoryMetadata updatedRepositoryMetadata = clusterAdmin().prepareGetRepositories(snapshotRepoName).get().repositories().get(0);
+        assertFalse(updatedRepositoryMetadata.settings().getAsBoolean(BlobStoreRepository.REMOTE_STORE_INDEX_SHALLOW_COPY.getKey(), false));
+
+        final String targetSnapshot = "target-snapshot";
+        assertAcked(startClone(snapshotRepoName, snapshot, targetSnapshot, indexName, remoteStoreEnabledIndexName).get());
+        assert (getLockFilesInRemoteStore(remoteStoreEnabledIndexName, remoteStoreRepoName).length == 2);
+        assertEquals(getSnapshot(snapshotRepoName, targetSnapshot).isRemoteStoreIndexShallowCopyEnabled(), true);
+    }
+
     public void testClonePreventsSnapshotDelete() throws Exception {
         final String clusterManagerName = internalCluster().startClusterManagerOnlyNode();
         internalCluster().startDataOnlyNode();
diff --git a/server/src/internalClusterTest/java/org/opensearch/snapshots/RestoreSnapshotIT.java b/server/src/internalClusterTest/java/org/opensearch/snapshots/RestoreSnapshotIT.java
index 9f492bbaee01a..e362b7f61e8e6 100644
--- a/server/src/internalClusterTest/java/org/opensearch/snapshots/RestoreSnapshotIT.java
+++ b/server/src/internalClusterTest/java/org/opensearch/snapshots/RestoreSnapshotIT.java
@@ -183,8 +183,8 @@ public void testRestoreRemoteStoreIndicesWithoutRemoteTranslog() throws IOExcept
 
     public void testRestoreOperationsShallowCopyEnabled(boolean remoteTranslogEnabled) throws IOException, ExecutionException,
         InterruptedException {
-        internalCluster().startClusterManagerOnlyNode();
-        final String primaryNode = internalCluster().startNode();
+        String clusterManagerNode = internalCluster().startClusterManagerOnlyNode();
+        String primary = internalCluster().startDataOnlyNode();
         String indexName1 = "testindex1";
         String indexName2 = "testindex2";
         String snapshotRepoName = "test-restore-snapshot-repo";
@@ -216,7 +216,7 @@ public void testRestoreOperationsShallowCopyEnabled(boolean remoteTranslogEnable
         indexDocuments(client, indexName2, numDocsInIndex2);
         ensureGreen(indexName1, indexName2);
 
-        final String secondNode = internalCluster().startNode();
+        internalCluster().startDataOnlyNode();
         logger.info("--> snapshot");
         CreateSnapshotResponse createSnapshotResponse = client.admin()
             .cluster()
@@ -273,10 +273,12 @@ public void testRestoreOperationsShallowCopyEnabled(boolean remoteTranslogEnable
         assertDocsPresentInIndex(client, restoredIndexName2, numDocsInIndex2);
 
         // deleting data for restoredIndexName1 and restoring from remote store.
-        internalCluster().stopRandomNode(InternalTestCluster.nameFilter(primaryNodeName(restoredIndexName1)));
+        internalCluster().stopRandomNode(InternalTestCluster.nameFilter(primary));
         ensureRed(restoredIndexName1);
-        assertAcked(client().admin().indices().prepareClose(restoredIndexName1));
-        client().admin()
+        // Re-initialize client to make sure we are not using client from stopped node.
+        client = client(clusterManagerNode);
+        assertAcked(client.admin().indices().prepareClose(restoredIndexName1));
+        client.admin()
             .cluster()
             .restoreRemoteStore(new RestoreRemoteStoreRequest().indices(restoredIndexName1), PlainActionFuture.newFuture());
         ensureYellowAndNoInitializingShards(restoredIndexName1);
@@ -300,7 +302,7 @@ public void testRestoreOperationsShallowCopyEnabled(boolean remoteTranslogEnable
         assertEquals(restoreSnapshotResponse3.status(), RestStatus.ACCEPTED);
         ensureGreen(restoredIndexName1Seg);
 
-        GetIndexResponse getIndexResponse = client().admin()
+        GetIndexResponse getIndexResponse = client.admin()
             .indices()
             .getIndex(new GetIndexRequest().indices(restoredIndexName1Seg).includeDefaults(true))
             .get();
@@ -331,7 +333,7 @@ public void testRestoreOperationsShallowCopyEnabled(boolean remoteTranslogEnable
         assertEquals(restoreSnapshotResponse4.status(), RestStatus.ACCEPTED);
         ensureGreen(restoredIndexName1Doc);
 
-        getIndexResponse = client().admin()
+        getIndexResponse = client.admin()
             .indices()
             .getIndex(new GetIndexRequest().indices(restoredIndexName1Doc).includeDefaults(true))
             .get();
@@ -347,8 +349,8 @@ public void testRestoreOperationsShallowCopyEnabled(boolean remoteTranslogEnable
     }
 
     public void testRestoreInSameRemoteStoreEnabledIndex() throws IOException {
-        internalCluster().startClusterManagerOnlyNode();
-        internalCluster().startNode();
+        String clusterManagerNode = internalCluster().startClusterManagerOnlyNode();
+        String primary = internalCluster().startDataOnlyNode();
         String indexName1 = "testindex1";
         String indexName2 = "testindex2";
         String snapshotRepoName = "test-restore-snapshot-repo";
@@ -378,7 +380,7 @@ public void testRestoreInSameRemoteStoreEnabledIndex() throws IOException {
         indexDocuments(client, indexName2, numDocsInIndex2);
         ensureGreen(indexName1, indexName2);
 
-        final String secondNode = internalCluster().startNode();
+        internalCluster().startDataOnlyNode();
         logger.info("--> snapshot");
         CreateSnapshotResponse createSnapshotResponse = client.admin()
             .cluster()
@@ -435,10 +437,12 @@ public void testRestoreInSameRemoteStoreEnabledIndex() throws IOException {
         assertDocsPresentInIndex(client, restoredIndexName2, numDocsInIndex2);
 
         // deleting data for restoredIndexName1 and restoring from remote store.
-        internalCluster().stopRandomNode(InternalTestCluster.nameFilter(primaryNodeName(indexName1)));
+        internalCluster().stopRandomNode(InternalTestCluster.nameFilter(primary));
         ensureRed(indexName1);
-        assertAcked(client().admin().indices().prepareClose(indexName1));
-        client().admin().cluster().restoreRemoteStore(new RestoreRemoteStoreRequest().indices(indexName1), PlainActionFuture.newFuture());
+        // Re-initialize client to make sure we are not using client from stopped node.
+        client = client(clusterManagerNode);
+        assertAcked(client.admin().indices().prepareClose(indexName1));
+        client.admin().cluster().restoreRemoteStore(new RestoreRemoteStoreRequest().indices(indexName1), PlainActionFuture.newFuture());
         ensureYellowAndNoInitializingShards(indexName1);
         ensureGreen(indexName1);
         assertDocsPresentInIndex(client(), indexName1, numDocsInIndex1);
@@ -449,8 +453,8 @@ public void testRestoreInSameRemoteStoreEnabledIndex() throws IOException {
     }
 
     public void testRestoreShallowCopySnapshotWithDifferentRepo() throws IOException {
-        internalCluster().startClusterManagerOnlyNode();
-        final String primaryNode = internalCluster().startNode();
+        String clusterManagerNode = internalCluster().startClusterManagerOnlyNode();
+        String primary = internalCluster().startDataOnlyNode();
         String indexName1 = "testindex1";
         String indexName2 = "testindex2";
         String snapshotRepoName = "test-restore-snapshot-repo";
@@ -479,7 +483,7 @@ public void testRestoreShallowCopySnapshotWithDifferentRepo() throws IOException
         indexDocuments(client, indexName2, numDocsInIndex2);
         ensureGreen(indexName1, indexName2);
 
-        final String secondNode = internalCluster().startNode();
+        internalCluster().startDataOnlyNode();
 
         logger.info("--> snapshot");
         CreateSnapshotResponse createSnapshotResponse = client.admin()
@@ -513,9 +517,11 @@ public void testRestoreShallowCopySnapshotWithDifferentRepo() throws IOException
         assertDocsPresentInIndex(client(), restoredIndexName1, numDocsInIndex1);
 
         // deleting data for restoredIndexName1 and restoring from remote store.
-        internalCluster().stopRandomNode(InternalTestCluster.nameFilter(primaryNodeName(restoredIndexName1)));
-        assertAcked(client().admin().indices().prepareClose(restoredIndexName1));
-        client().admin()
+        internalCluster().stopRandomNode(InternalTestCluster.nameFilter(primary));
+        // Re-initialize client to make sure we are not using client from stopped node.
+        client = client(clusterManagerNode);
+        assertAcked(client.admin().indices().prepareClose(restoredIndexName1));
+        client.admin()
             .cluster()
             .restoreRemoteStore(new RestoreRemoteStoreRequest().indices(restoredIndexName1), PlainActionFuture.newFuture());
         ensureYellowAndNoInitializingShards(restoredIndexName1);
diff --git a/server/src/main/java/org/opensearch/action/ActionModule.java b/server/src/main/java/org/opensearch/action/ActionModule.java
index 902ae7cc54e3f..56d1758161ced 100644
--- a/server/src/main/java/org/opensearch/action/ActionModule.java
+++ b/server/src/main/java/org/opensearch/action/ActionModule.java
@@ -462,9 +462,9 @@
 
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
-import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentSkipListSet;
@@ -1044,7 +1044,7 @@ public static class DynamicActionRegistry {
 
         // A dynamic registry to add or remove Route / RestSendToExtensionAction pairs
         // at times other than node bootstrap.
-        private final Map<RestHandler.Route, RestSendToExtensionAction> routeRegistry = new ConcurrentHashMap<>();
+        private final Map<NamedRoute, RestSendToExtensionAction> routeRegistry = new ConcurrentHashMap<>();
 
         private final Set<String> registeredActionNames = new ConcurrentSkipListSet<>();
 
@@ -1112,26 +1112,37 @@ public boolean isActionRegistered(String actionName) {
         }
 
         /**
-         * Add a dynamic action to the registry.
+         * Adds a dynamic route to the registry.
          *
          * @param route The route instance to add
          * @param action The corresponding instance of RestSendToExtensionAction to execute
          */
-        public void registerDynamicRoute(RestHandler.Route route, RestSendToExtensionAction action) {
+        public void registerDynamicRoute(NamedRoute route, RestSendToExtensionAction action) {
             requireNonNull(route, "route is required");
             requireNonNull(action, "action is required");
-            Optional<String> routeName = Optional.empty();
-            if (route instanceof NamedRoute) {
-                routeName = Optional.of(((NamedRoute) route).name());
-                if (isActionRegistered(routeName.get()) || registeredActionNames.contains(routeName.get())) {
-                    throw new IllegalArgumentException("route [" + route + "] already registered");
-                }
+
+            String routeName = route.name();
+            requireNonNull(routeName, "route name is required");
+            if (isActionRegistered(routeName)) {
+                throw new IllegalArgumentException("route [" + route + "] already registered");
             }
+
+            Set<String> actionNames = route.actionNames();
+            if (!Collections.disjoint(actionNames, registeredActionNames)) {
+                Set<String> alreadyRegistered = new HashSet<>(registeredActionNames);
+                alreadyRegistered.retainAll(actionNames);
+                String acts = String.join(", ", alreadyRegistered);
+                throw new IllegalArgumentException(
+                    "action" + (alreadyRegistered.size() > 1 ? "s [" : " [") + acts + "] already registered"
+                );
+            }
+
             if (routeRegistry.containsKey(route)) {
                 throw new IllegalArgumentException("route [" + route + "] already registered");
             }
             routeRegistry.put(route, action);
-            routeName.ifPresent(registeredActionNames::add);
+            registeredActionNames.add(routeName);
+            registeredActionNames.addAll(actionNames);
         }
 
         /**
@@ -1139,14 +1150,14 @@ public void registerDynamicRoute(RestHandler.Route route, RestSendToExtensionAct
          *
          * @param route The route to remove
          */
-        public void unregisterDynamicRoute(RestHandler.Route route) {
+        public void unregisterDynamicRoute(NamedRoute route) {
             requireNonNull(route, "route is required");
             if (routeRegistry.remove(route) == null) {
                 throw new IllegalArgumentException("action [" + route + "] was not registered");
             }
-            if (route instanceof NamedRoute) {
-                registeredActionNames.remove(((NamedRoute) route).name());
-            }
+
+            registeredActionNames.remove(route.name());
+            registeredActionNames.removeAll(route.actionNames());
         }
 
         /**
diff --git a/server/src/main/java/org/opensearch/action/admin/cluster/node/stats/NodeStats.java b/server/src/main/java/org/opensearch/action/admin/cluster/node/stats/NodeStats.java
index 6b8e06594acb7..4cdc54f9c7952 100644
--- a/server/src/main/java/org/opensearch/action/admin/cluster/node/stats/NodeStats.java
+++ b/server/src/main/java/org/opensearch/action/admin/cluster/node/stats/NodeStats.java
@@ -193,7 +193,7 @@ public NodeStats(StreamInput in) throws IOException {
         } else {
             taskCancellationStats = null;
         }
-        if (in.getVersion().onOrAfter(Version.V_3_0_0)) { // TODO Update to 2_9_0 when we backport to 2.x
+        if (in.getVersion().onOrAfter(Version.V_2_9_0)) {
             searchPipelineStats = in.readOptionalWriteable(SearchPipelineStats::new);
         } else {
             searchPipelineStats = null;
@@ -427,7 +427,7 @@ public void writeTo(StreamOutput out) throws IOException {
         if (out.getVersion().onOrAfter(Version.V_2_9_0)) {
             out.writeOptionalWriteable(taskCancellationStats);
         }
-        if (out.getVersion().onOrAfter(Version.V_3_0_0)) { // TODO: Update to 2_9_0 once we backport to 2.x
+        if (out.getVersion().onOrAfter(Version.V_2_9_0)) {
             out.writeOptionalWriteable(searchPipelineStats);
         }
     }
diff --git a/server/src/main/java/org/opensearch/cluster/SnapshotsInProgress.java b/server/src/main/java/org/opensearch/cluster/SnapshotsInProgress.java
index d827dc6409778..ffc99c34fcac5 100644
--- a/server/src/main/java/org/opensearch/cluster/SnapshotsInProgress.java
+++ b/server/src/main/java/org/opensearch/cluster/SnapshotsInProgress.java
@@ -167,7 +167,8 @@ public static Entry startClone(
             version,
             source,
             Map.of(),
-            false // TODO: need to pull this value from the original snapshot, use whatever we set during snapshot create.
+            false // initialising to false, will be updated in startCloning method of SnapshotsService while updating entry with
+                  // clone jobs
         );
     }
 
@@ -453,6 +454,26 @@ public Entry withClones(final Map<RepositoryShardId, ShardSnapshotStatus> update
             );
         }
 
+        public Entry withRemoteStoreIndexShallowCopy(final boolean remoteStoreIndexShallowCopy) {
+            return new Entry(
+                snapshot,
+                includeGlobalState,
+                partial,
+                state,
+                indices,
+                dataStreams,
+                startTime,
+                repositoryStateId,
+                shards,
+                failure,
+                userMetadata,
+                version,
+                source,
+                clones,
+                remoteStoreIndexShallowCopy
+            );
+        }
+
         /**
          * Create a new instance by aborting this instance. Moving all in-progress shards to {@link ShardState#ABORTED} if assigned to a
          * data node or to {@link ShardState#FAILED} if not assigned to any data node.
diff --git a/server/src/main/java/org/opensearch/cluster/metadata/MetadataCreateIndexService.java b/server/src/main/java/org/opensearch/cluster/metadata/MetadataCreateIndexService.java
index 0a49feec61621..3fff6e8823e9e 100644
--- a/server/src/main/java/org/opensearch/cluster/metadata/MetadataCreateIndexService.java
+++ b/server/src/main/java/org/opensearch/cluster/metadata/MetadataCreateIndexService.java
@@ -72,7 +72,6 @@
 import org.opensearch.common.settings.IndexScopedSettings;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
-import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.xcontent.XContentHelper;
 import org.opensearch.core.common.Strings;
 import org.opensearch.core.xcontent.NamedXContentRegistry;
@@ -137,7 +136,6 @@
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_REMOTE_TRANSLOG_STORE_REPOSITORY;
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_REPLICATION_TYPE;
 import static org.opensearch.cluster.metadata.Metadata.DEFAULT_REPLICA_COUNT_SETTING;
-import static org.opensearch.common.util.FeatureFlags.REMOTE_STORE;
 import static org.opensearch.indices.IndicesService.CLUSTER_REMOTE_STORE_REPOSITORY_SETTING;
 import static org.opensearch.indices.IndicesService.CLUSTER_REMOTE_TRANSLOG_REPOSITORY_SETTING;
 import static org.opensearch.indices.IndicesService.CLUSTER_REMOTE_STORE_ENABLED_SETTING;
@@ -585,8 +583,7 @@ private ClusterState applyCreateIndexRequestWithV1Templates(
             settings,
             indexScopedSettings,
             shardLimitValidator,
-            indexSettingProviders,
-            systemIndices.validateSystemIndex(request.index())
+            indexSettingProviders
         );
         int routingNumShards = getIndexNumberOfRoutingShards(aggregatedIndexSettings, null);
         IndexMetadata tmpImd = buildAndValidateTemporaryIndexMetadata(currentState, aggregatedIndexSettings, request, routingNumShards);
@@ -650,8 +647,7 @@ private ClusterState applyCreateIndexRequestWithV2Template(
             settings,
             indexScopedSettings,
             shardLimitValidator,
-            indexSettingProviders,
-            systemIndices.validateSystemIndex(request.index())
+            indexSettingProviders
         );
         int routingNumShards = getIndexNumberOfRoutingShards(aggregatedIndexSettings, null);
         IndexMetadata tmpImd = buildAndValidateTemporaryIndexMetadata(currentState, aggregatedIndexSettings, request, routingNumShards);
@@ -731,8 +727,7 @@ private ClusterState applyCreateIndexRequestWithExistingMetadata(
             settings,
             indexScopedSettings,
             shardLimitValidator,
-            indexSettingProviders,
-            sourceMetadata.isSystem()
+            indexSettingProviders
         );
         final int routingNumShards = getIndexNumberOfRoutingShards(aggregatedIndexSettings, sourceMetadata);
         IndexMetadata tmpImd = buildAndValidateTemporaryIndexMetadata(currentState, aggregatedIndexSettings, request, routingNumShards);
@@ -815,8 +810,7 @@ static Settings aggregateIndexSettings(
         Settings settings,
         IndexScopedSettings indexScopedSettings,
         ShardLimitValidator shardLimitValidator,
-        Set<IndexSettingProvider> indexSettingProviders,
-        boolean isSystemIndex
+        Set<IndexSettingProvider> indexSettingProviders
     ) {
         // Create builders for the template and request settings. We transform these into builders
         // because we may want settings to be "removed" from these prior to being set on the new
@@ -900,18 +894,8 @@ static Settings aggregateIndexSettings(
         indexSettingsBuilder.put(IndexMetadata.SETTING_INDEX_PROVIDED_NAME, request.getProvidedName());
         indexSettingsBuilder.put(SETTING_INDEX_UUID, UUIDs.randomBase64UUID());
 
-        if (isSystemIndex || IndexMetadata.INDEX_HIDDEN_SETTING.get(request.settings())) {
-            logger.warn(
-                "Setting replication.type: DOCUMENT will be used for Index until Segment Replication supports System and Hidden indices"
-            );
-            indexSettingsBuilder.put(SETTING_REPLICATION_TYPE, ReplicationType.DOCUMENT);
-            if (FeatureFlags.isEnabled(REMOTE_STORE)) {
-                indexSettingsBuilder.put(SETTING_REMOTE_STORE_ENABLED, false);
-            }
-        } else {
-            updateReplicationStrategy(indexSettingsBuilder, request.settings(), settings);
-            updateRemoteStoreSettings(indexSettingsBuilder, request.settings(), settings);
-        }
+        updateReplicationStrategy(indexSettingsBuilder, request.settings(), settings);
+        updateRemoteStoreSettings(indexSettingsBuilder, request.settings(), settings);
 
         if (sourceMetadata != null) {
             assert request.resizeType() != null;
diff --git a/server/src/main/java/org/opensearch/common/blobstore/BlobContainer.java b/server/src/main/java/org/opensearch/common/blobstore/BlobContainer.java
index ac38768c9f3d3..e626824e7e271 100644
--- a/server/src/main/java/org/opensearch/common/blobstore/BlobContainer.java
+++ b/server/src/main/java/org/opensearch/common/blobstore/BlobContainer.java
@@ -32,10 +32,14 @@
 
 package org.opensearch.common.blobstore;
 
+import org.opensearch.action.ActionListener;
+
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.file.FileAlreadyExistsException;
 import java.nio.file.NoSuchFileException;
+import java.util.ArrayList;
+import java.util.Comparator;
 import java.util.List;
 import java.util.Map;
 
@@ -191,4 +195,47 @@ default long readBlobPreferredLength() {
      * @throws  IOException if there were any failures in reading from the blob container.
      */
     Map<String, BlobMetadata> listBlobsByPrefix(String blobNamePrefix) throws IOException;
+
+    /**
+     * The type representing sort order of blob names
+     */
+    enum BlobNameSortOrder {
+
+        LEXICOGRAPHIC(Comparator.comparing(BlobMetadata::name));
+
+        final Comparator<BlobMetadata> comparator;
+
+        public Comparator<BlobMetadata> comparator() {
+            return comparator;
+        }
+
+        BlobNameSortOrder(final Comparator<BlobMetadata> comparator) {
+            this.comparator = comparator;
+        }
+    }
+
+    /**
+     * Lists all blobs in the container that match the specified prefix in lexicographic order
+     * @param blobNamePrefix The prefix to match against blob names in the container.
+     * @param limit Limits the result size to min(limit, number of keys)
+     * @param blobNameSortOrder Comparator to sort keys with
+     * @param listener the listener to be notified upon request completion
+     */
+    default void listBlobsByPrefixInSortedOrder(
+        String blobNamePrefix,
+        int limit,
+        BlobNameSortOrder blobNameSortOrder,
+        ActionListener<List<BlobMetadata>> listener
+    ) {
+        if (limit < 0) {
+            throw new IllegalArgumentException("limit should not be a negative value");
+        }
+        try {
+            List<BlobMetadata> blobNames = new ArrayList<>(listBlobsByPrefix(blobNamePrefix).values());
+            blobNames.sort(blobNameSortOrder.comparator());
+            listener.onResponse(blobNames.subList(0, Math.min(blobNames.size(), limit)));
+        } catch (Exception e) {
+            listener.onFailure(e);
+        }
+    }
 }
diff --git a/server/src/main/java/org/opensearch/common/util/concurrent/ThreadContext.java b/server/src/main/java/org/opensearch/common/util/concurrent/ThreadContext.java
index 025fb7a36b684..9dd5d21a00231 100644
--- a/server/src/main/java/org/opensearch/common/util/concurrent/ThreadContext.java
+++ b/server/src/main/java/org/opensearch/common/util/concurrent/ThreadContext.java
@@ -149,7 +149,7 @@ public StoredContext stashContext() {
          * Otherwise when context is stash, it should be empty.
          */
 
-        ThreadContextStruct threadContextStruct = DEFAULT_CONTEXT;
+        ThreadContextStruct threadContextStruct = DEFAULT_CONTEXT.putPersistent(context.persistentHeaders);
 
         if (context.requestHeaders.containsKey(Task.X_OPAQUE_ID)) {
             threadContextStruct = threadContextStruct.putHeaders(
@@ -262,6 +262,7 @@ public StoredContext newStoredContext(boolean preserveResponseHeaders, Collectio
                 originalContext.requestHeaders,
                 originalContext.responseHeaders,
                 newTransientHeaders,
+                originalContext.persistentHeaders,
                 originalContext.isSystemContext,
                 originalContext.warningHeadersSize
             );
@@ -337,7 +338,7 @@ public void setHeaders(Tuple<Map<String, String>, Map<String, Set<String>>> head
         if (requestHeaders.isEmpty() && responseHeaders.isEmpty()) {
             struct = ThreadContextStruct.EMPTY;
         } else {
-            struct = new ThreadContextStruct(requestHeaders, responseHeaders, Collections.emptyMap(), false);
+            struct = new ThreadContextStruct(requestHeaders, responseHeaders, Collections.emptyMap(), Collections.emptyMap(), false);
         }
         threadLocal.set(struct);
     }
@@ -375,6 +376,13 @@ public String getHeader(String key) {
         return value;
     }
 
+    /**
+     * Returns the persistent header for the given key or <code>null</code> if not present - persistent headers cannot be stashed
+     */
+    public Object getPersistent(String key) {
+        return threadLocal.get().persistentHeaders.get(key);
+    }
+
     /**
      * Returns all of the request headers from the thread's context.<br>
      * <b>Be advised, headers might contain credentials.</b>
@@ -434,6 +442,20 @@ public void putHeader(Map<String, String> header) {
         threadLocal.set(threadLocal.get().putHeaders(header));
     }
 
+    /**
+     * Puts a persistent header into the context - persistent headers cannot be stashed
+     */
+    public void putPersistent(String key, Object value) {
+        threadLocal.set(threadLocal.get().putPersistent(key, value));
+    }
+
+    /**
+     * Puts all of the given headers into this persistent context - persistent headers cannot be stashed
+     */
+    public void putPersistent(Map<String, Object> persistentHeaders) {
+        threadLocal.set(threadLocal.get().putPersistent(persistentHeaders));
+    }
+
     /**
      * Puts a transient header object into this context
      */
@@ -566,12 +588,14 @@ private static final class ThreadContextStruct {
             Collections.emptyMap(),
             Collections.emptyMap(),
             Collections.emptyMap(),
+            Collections.emptyMap(),
             false
         );
 
         private final Map<String, String> requestHeaders;
         private final Map<String, Object> transientHeaders;
         private final Map<String, Set<String>> responseHeaders;
+        private final Map<String, Object> persistentHeaders;
         private final boolean isSystemContext;
         // saving current warning headers' size not to recalculate the size with every new warning header
         private final long warningHeadersSize;
@@ -580,18 +604,20 @@ private ThreadContextStruct setSystemContext() {
             if (isSystemContext) {
                 return this;
             }
-            return new ThreadContextStruct(requestHeaders, responseHeaders, transientHeaders, true);
+            return new ThreadContextStruct(requestHeaders, responseHeaders, transientHeaders, persistentHeaders, true);
         }
 
         private ThreadContextStruct(
             Map<String, String> requestHeaders,
             Map<String, Set<String>> responseHeaders,
             Map<String, Object> transientHeaders,
+            Map<String, Object> persistentHeaders,
             boolean isSystemContext
         ) {
             this.requestHeaders = requestHeaders;
             this.responseHeaders = responseHeaders;
             this.transientHeaders = transientHeaders;
+            this.persistentHeaders = persistentHeaders;
             this.isSystemContext = isSystemContext;
             this.warningHeadersSize = 0L;
         }
@@ -600,12 +626,14 @@ private ThreadContextStruct(
             Map<String, String> requestHeaders,
             Map<String, Set<String>> responseHeaders,
             Map<String, Object> transientHeaders,
+            Map<String, Object> persistentHeaders,
             boolean isSystemContext,
             long warningHeadersSize
         ) {
             this.requestHeaders = requestHeaders;
             this.responseHeaders = responseHeaders;
             this.transientHeaders = transientHeaders;
+            this.persistentHeaders = persistentHeaders;
             this.isSystemContext = isSystemContext;
             this.warningHeadersSize = warningHeadersSize;
         }
@@ -614,13 +642,13 @@ private ThreadContextStruct(
          * This represents the default context and it should only ever be called by {@link #DEFAULT_CONTEXT}.
          */
         private ThreadContextStruct() {
-            this(Collections.emptyMap(), Collections.emptyMap(), Collections.emptyMap(), false);
+            this(Collections.emptyMap(), Collections.emptyMap(), Collections.emptyMap(), Collections.emptyMap(), false);
         }
 
         private ThreadContextStruct putRequest(String key, String value) {
             Map<String, String> newRequestHeaders = new HashMap<>(this.requestHeaders);
             putSingleHeader(key, value, newRequestHeaders);
-            return new ThreadContextStruct(newRequestHeaders, responseHeaders, transientHeaders, isSystemContext);
+            return new ThreadContextStruct(newRequestHeaders, responseHeaders, transientHeaders, persistentHeaders, isSystemContext);
         }
 
         private static <T> void putSingleHeader(String key, T value, Map<String, T> newHeaders) {
@@ -637,7 +665,25 @@ private ThreadContextStruct putHeaders(Map<String, String> headers) {
                 for (Map.Entry<String, String> entry : headers.entrySet()) {
                     putSingleHeader(entry.getKey(), entry.getValue(), newHeaders);
                 }
-                return new ThreadContextStruct(newHeaders, responseHeaders, transientHeaders, isSystemContext);
+                return new ThreadContextStruct(newHeaders, responseHeaders, transientHeaders, persistentHeaders, isSystemContext);
+            }
+        }
+
+        private ThreadContextStruct putPersistent(String key, Object value) {
+            Map<String, Object> newPersistentHeaders = new HashMap<>(this.persistentHeaders);
+            putSingleHeader(key, value, newPersistentHeaders);
+            return new ThreadContextStruct(requestHeaders, responseHeaders, transientHeaders, newPersistentHeaders, isSystemContext);
+        }
+
+        private ThreadContextStruct putPersistent(Map<String, Object> headers) {
+            if (headers.isEmpty()) {
+                return this;
+            } else {
+                final Map<String, Object> newPersistentHeaders = new HashMap<>(this.persistentHeaders);
+                for (Map.Entry<String, Object> entry : headers.entrySet()) {
+                    putSingleHeader(entry.getKey(), entry.getValue(), newPersistentHeaders);
+                }
+                return new ThreadContextStruct(requestHeaders, responseHeaders, transientHeaders, newPersistentHeaders, isSystemContext);
             }
         }
 
@@ -658,7 +704,7 @@ private ThreadContextStruct putResponseHeaders(Map<String, Set<String>> headers)
                     newResponseHeaders.put(key, entry.getValue());
                 }
             }
-            return new ThreadContextStruct(requestHeaders, newResponseHeaders, transientHeaders, isSystemContext);
+            return new ThreadContextStruct(requestHeaders, newResponseHeaders, transientHeaders, persistentHeaders, isSystemContext);
         }
 
         private ThreadContextStruct putResponse(
@@ -695,6 +741,7 @@ private ThreadContextStruct putResponse(
                         requestHeaders,
                         responseHeaders,
                         transientHeaders,
+                        persistentHeaders,
                         isSystemContext,
                         newWarningHeaderSize
                     );
@@ -730,7 +777,14 @@ private ThreadContextStruct putResponse(
                     return this;
                 }
             }
-            return new ThreadContextStruct(requestHeaders, newResponseHeaders, transientHeaders, isSystemContext, newWarningHeaderSize);
+            return new ThreadContextStruct(
+                requestHeaders,
+                newResponseHeaders,
+                transientHeaders,
+                persistentHeaders,
+                isSystemContext,
+                newWarningHeaderSize
+            );
         }
 
         private ThreadContextStruct putTransient(Map<String, Object> values) {
@@ -738,13 +792,13 @@ private ThreadContextStruct putTransient(Map<String, Object> values) {
             for (Map.Entry<String, Object> entry : values.entrySet()) {
                 putSingleHeader(entry.getKey(), entry.getValue(), newTransient);
             }
-            return new ThreadContextStruct(requestHeaders, responseHeaders, newTransient, isSystemContext);
+            return new ThreadContextStruct(requestHeaders, responseHeaders, newTransient, persistentHeaders, isSystemContext);
         }
 
         private ThreadContextStruct putTransient(String key, Object value) {
             Map<String, Object> newTransient = new HashMap<>(this.transientHeaders);
             putSingleHeader(key, value, newTransient);
-            return new ThreadContextStruct(requestHeaders, responseHeaders, newTransient, isSystemContext);
+            return new ThreadContextStruct(requestHeaders, responseHeaders, newTransient, persistentHeaders, isSystemContext);
         }
 
         private ThreadContextStruct copyHeaders(Iterable<Map.Entry<String, String>> headers) {
diff --git a/server/src/main/java/org/opensearch/extensions/ExtensionDependency.java b/server/src/main/java/org/opensearch/extensions/ExtensionDependency.java
index 1423a30bbe307..56c9f0387b13e 100644
--- a/server/src/main/java/org/opensearch/extensions/ExtensionDependency.java
+++ b/server/src/main/java/org/opensearch/extensions/ExtensionDependency.java
@@ -16,10 +16,6 @@
 import org.opensearch.common.io.stream.StreamInput;
 import org.opensearch.common.io.stream.StreamOutput;
 import org.opensearch.common.io.stream.Writeable;
-import org.opensearch.core.common.Strings;
-import org.opensearch.core.xcontent.XContentParser;
-
-import static org.opensearch.common.xcontent.XContentParserUtils.ensureExpectedToken;
 
 /**
  * This class handles the dependent extensions information
@@ -60,39 +56,6 @@ public void writeTo(StreamOutput out) throws IOException {
         out.writeVersion(version);
     }
 
-    public static ExtensionDependency parse(XContentParser parser) throws IOException {
-        String uniqueId = null;
-        Version version = null;
-        ensureExpectedToken(XContentParser.Token.START_OBJECT, parser.currentToken(), parser);
-        while (parser.nextToken() != XContentParser.Token.END_OBJECT) {
-            String fieldName = parser.currentName();
-            parser.nextToken();
-
-            switch (fieldName) {
-                case UNIQUE_ID:
-                    uniqueId = parser.text();
-                    break;
-                case VERSION:
-                    try {
-                        version = Version.fromString(parser.text());
-                    } catch (IllegalArgumentException e) {
-                        throw e;
-                    }
-                    break;
-                default:
-                    parser.skipChildren();
-                    break;
-            }
-        }
-        if (Strings.isNullOrEmpty(uniqueId)) {
-            throw new IOException("Required field [uniqueId] is missing in the request for the dependent extension");
-        } else if (version == null) {
-            throw new IOException("Required field [version] is missing in the request for the dependent extension");
-        }
-        return new ExtensionDependency(uniqueId, version);
-
-    }
-
     /**
     * The uniqueId of the dependency extension
     *
diff --git a/server/src/main/java/org/opensearch/extensions/ExtensionsManager.java b/server/src/main/java/org/opensearch/extensions/ExtensionsManager.java
index 9987497b5fac0..cb22c8d864b1b 100644
--- a/server/src/main/java/org/opensearch/extensions/ExtensionsManager.java
+++ b/server/src/main/java/org/opensearch/extensions/ExtensionsManager.java
@@ -105,7 +105,7 @@ public static enum OpenSearchRequestType {
     /**
      * Instantiate a new ExtensionsManager object to handle requests and responses from extensions. This is called during Node bootstrap.
      *
-     * @param additionalSettings  Additional settings to read in from extensions.yml
+     * @param additionalSettings  Additional settings to read in from extension initialization request
      * @throws IOException  If the extensions discovery file is not properly retrieved.
      */
     public ExtensionsManager(Set<Setting<?>> additionalSettings) throws IOException {
@@ -504,4 +504,8 @@ void setAddSettingsUpdateConsumerRequestHandler(AddSettingsUpdateConsumerRequest
     Settings getEnvironmentSettings() {
         return environmentSettings;
     }
+
+    public Set<Setting<?>> getAdditionalSettings() {
+        return this.additionalSettings;
+    }
 }
diff --git a/server/src/main/java/org/opensearch/extensions/rest/RestInitializeExtensionAction.java b/server/src/main/java/org/opensearch/extensions/rest/RestInitializeExtensionAction.java
index e0806f8172278..878673b77a4a9 100644
--- a/server/src/main/java/org/opensearch/extensions/rest/RestInitializeExtensionAction.java
+++ b/server/src/main/java/org/opensearch/extensions/rest/RestInitializeExtensionAction.java
@@ -8,27 +8,37 @@
 
 package org.opensearch.extensions.rest;
 
+import org.opensearch.Version;
 import org.opensearch.client.node.NodeClient;
+import org.opensearch.common.collect.Tuple;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.xcontent.XContentHelper;
+import org.opensearch.core.common.Strings;
+import org.opensearch.core.xcontent.MediaType;
 import org.opensearch.core.xcontent.XContentBuilder;
-import org.opensearch.core.xcontent.XContentParser;
 import org.opensearch.extensions.ExtensionDependency;
 import org.opensearch.extensions.ExtensionScopedSettings;
 import org.opensearch.extensions.ExtensionsManager;
 import org.opensearch.extensions.ExtensionsSettings.Extension;
 import org.opensearch.rest.BaseRestHandler;
 import org.opensearch.rest.BytesRestResponse;
+import org.opensearch.rest.NamedRoute;
 import org.opensearch.rest.RestRequest;
 import org.opensearch.rest.RestStatus;
 import org.opensearch.transport.ConnectTransportException;
 
 import java.io.IOException;
 import java.util.ArrayList;
-import java.util.Collections;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
+import java.util.Set;
 import java.util.concurrent.CompletionException;
 import java.util.concurrent.TimeoutException;
+import java.util.stream.Collectors;
 
-import static org.opensearch.common.xcontent.XContentParserUtils.ensureExpectedToken;
 import static org.opensearch.rest.RestRequest.Method.POST;
 
 /**
@@ -45,7 +55,7 @@ public String getName() {
 
     @Override
     public List<Route> routes() {
-        return List.of(new Route(POST, "/_extensions/initialize"));
+        return List.of(new NamedRoute.Builder().method(POST).path("/_extensions/initialize").uniqueName("extensions:initialize").build());
     }
 
     public RestInitializeExtensionAction(ExtensionsManager extensionsManager) {
@@ -62,36 +72,79 @@ public RestChannelConsumer prepareRequest(RestRequest request, NodeClient client
         String openSearchVersion = null;
         String minimumCompatibleVersion = null;
         List<ExtensionDependency> dependencies = new ArrayList<>();
+        Set<String> additionalSettingsKeys = extensionsManager.getAdditionalSettings()
+            .stream()
+            .map(s -> s.getKey())
+            .collect(Collectors.toSet());
 
-        try (XContentParser parser = request.contentParser()) {
-            parser.nextToken();
-            ensureExpectedToken(XContentParser.Token.START_OBJECT, parser.currentToken(), parser);
-            while (parser.nextToken() != XContentParser.Token.END_OBJECT) {
-                String currentFieldName = parser.currentName();
-                parser.nextToken();
-                if ("name".equals(currentFieldName)) {
-                    name = parser.text();
-                } else if ("uniqueId".equals(currentFieldName)) {
-                    uniqueId = parser.text();
-                } else if ("hostAddress".equals(currentFieldName)) {
-                    hostAddress = parser.text();
-                } else if ("port".equals(currentFieldName)) {
-                    port = parser.text();
-                } else if ("version".equals(currentFieldName)) {
-                    version = parser.text();
-                } else if ("opensearchVersion".equals(currentFieldName)) {
-                    openSearchVersion = parser.text();
-                } else if ("minimumCompatibleVersion".equals(currentFieldName)) {
-                    minimumCompatibleVersion = parser.text();
-                } else if ("dependencies".equals(currentFieldName)) {
-                    ensureExpectedToken(XContentParser.Token.START_ARRAY, parser.currentToken(), parser);
-                    while (parser.nextToken() != XContentParser.Token.END_ARRAY) {
-                        dependencies.add(ExtensionDependency.parse(parser));
+        Tuple<? extends MediaType, Map<String, Object>> unreadExtensionTuple = XContentHelper.convertToMap(
+            request.content(),
+            false,
+            request.getXContentType().xContent().mediaType()
+        );
+        Map<String, Object> extensionMap = unreadExtensionTuple.v2();
+
+        ExtensionScopedSettings extAdditionalSettings = new ExtensionScopedSettings(extensionsManager.getAdditionalSettings());
+
+        try {
+            // checking to see whether any required fields are missing from extension initialization request or not
+            String[] requiredFields = {
+                "name",
+                "uniqueId",
+                "hostAddress",
+                "port",
+                "version",
+                "opensearchVersion",
+                "minimumCompatibleVersion" };
+            List<String> missingFields = Arrays.stream(requiredFields)
+                .filter(field -> !extensionMap.containsKey(field))
+                .collect(Collectors.toList());
+            if (!missingFields.isEmpty()) {
+                throw new IOException("Extension is missing these required fields : " + missingFields);
+            }
+
+            // Parse extension dependencies
+            List<ExtensionDependency> extensionDependencyList = new ArrayList<ExtensionDependency>();
+            if (extensionMap.get("dependencies") != null) {
+                List<HashMap<String, ?>> extensionDependencies = new ArrayList<>(
+                    (Collection<HashMap<String, ?>>) extensionMap.get("dependencies")
+                );
+                for (HashMap<String, ?> dependency : extensionDependencies) {
+                    if (Strings.isNullOrEmpty((String) dependency.get("uniqueId"))) {
+                        throw new IOException("Required field [uniqueId] is missing in the request for the dependent extension");
+                    } else if (dependency.get("version") == null) {
+                        throw new IOException("Required field [version] is missing in the request for the dependent extension");
                     }
+                    extensionDependencyList.add(
+                        new ExtensionDependency(
+                            dependency.get("uniqueId").toString(),
+                            Version.fromString(dependency.get("version").toString())
+                        )
+                    );
                 }
             }
+
+            Map<String, ?> additionalSettingsMap = extensionMap.entrySet()
+                .stream()
+                .filter(kv -> additionalSettingsKeys.contains(kv.getKey()))
+                .collect(Collectors.toMap(map -> map.getKey(), map -> map.getValue()));
+
+            Settings.Builder output = Settings.builder();
+            output.loadFromMap(additionalSettingsMap);
+            extAdditionalSettings.applySettings(output.build());
+
+            // Create extension read from initialization request
+            name = extensionMap.get("name").toString();
+            uniqueId = extensionMap.get("uniqueId").toString();
+            hostAddress = extensionMap.get("hostAddress").toString();
+            port = extensionMap.get("port").toString();
+            version = extensionMap.get("version").toString();
+            openSearchVersion = extensionMap.get("opensearchVersion").toString();
+            minimumCompatibleVersion = extensionMap.get("minimumCompatibleVersion").toString();
+            dependencies = extensionDependencyList;
         } catch (IOException e) {
-            throw new IOException("Missing attribute", e);
+            logger.warn("loading extension has been failed because of exception : " + e.getMessage());
+            return channel -> channel.sendResponse(new BytesRestResponse(RestStatus.INTERNAL_SERVER_ERROR, e.getMessage()));
         }
 
         Extension extension = new Extension(
@@ -103,8 +156,7 @@ public RestChannelConsumer prepareRequest(RestRequest request, NodeClient client
             openSearchVersion,
             minimumCompatibleVersion,
             dependencies,
-            // TODO add this to the API (https://github.com/opensearch-project/OpenSearch/issues/8032)
-            new ExtensionScopedSettings(Collections.emptySet())
+            extAdditionalSettings
         );
         try {
             extensionsManager.loadExtension(extension);
@@ -136,6 +188,5 @@ public RestChannelConsumer prepareRequest(RestRequest request, NodeClient client
                 channel.sendResponse(new BytesRestResponse(RestStatus.ACCEPTED, builder));
             }
         };
-
     }
 }
diff --git a/server/src/main/java/org/opensearch/extensions/rest/RestSendToExtensionAction.java b/server/src/main/java/org/opensearch/extensions/rest/RestSendToExtensionAction.java
index 073b3f3f45818..3dd6056bb36cf 100644
--- a/server/src/main/java/org/opensearch/extensions/rest/RestSendToExtensionAction.java
+++ b/server/src/main/java/org/opensearch/extensions/rest/RestSendToExtensionAction.java
@@ -33,9 +33,9 @@
 import java.nio.charset.StandardCharsets;
 import java.security.Principal;
 import java.util.ArrayList;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
-import java.util.Optional;
 import java.util.Set;
 import java.util.stream.Collectors;
 import java.util.concurrent.CompletableFuture;
@@ -90,33 +90,43 @@ public RestSendToExtensionAction(
 
         List<Route> restActionsAsRoutes = new ArrayList<>();
         for (String restAction : restActionsRequest.getRestActions()) {
-            Optional<String> name = Optional.empty();
+
+            // TODO Find a better way to parse these to avoid code-smells
+
+            String name;
+            Set<String> actionNames = new HashSet<>();
             String[] parts = restAction.split(" ");
-            if (parts.length < 2) {
-                throw new IllegalArgumentException("REST action must contain at least a REST method and route");
+            if (parts.length < 3) {
+                throw new IllegalArgumentException("REST action must contain at least a REST method, a route and a unique name");
             }
             try {
                 method = RestRequest.Method.valueOf(parts[0].trim());
                 path = pathPrefix + parts[1].trim();
-                if (parts.length > 2) {
-                    name = Optional.of(parts[2].trim());
+                name = parts[2].trim();
+
+                // comma-separated action names
+                if (parts.length > 3) {
+                    String[] actions = parts[3].split(",");
+                    for (String action : actions) {
+                        String trimmed = action.trim();
+                        if (!trimmed.isEmpty()) {
+                            actionNames.add(trimmed);
+                        }
+                    }
                 }
             } catch (IndexOutOfBoundsException | IllegalArgumentException e) {
                 throw new IllegalArgumentException(restAction + " does not begin with a valid REST method");
             }
-            logger.info("Registering: " + method + " " + path);
-            if (name.isPresent()) {
-                NamedRoute nr = new NamedRoute(method, path, name.get());
-                restActionsAsRoutes.add(nr);
-                dynamicActionRegistry.registerDynamicRoute(nr, this);
-            } else {
-                Route r = new Route(method, path);
-                restActionsAsRoutes.add(r);
-                dynamicActionRegistry.registerDynamicRoute(r, this);
-            }
+            logger.info("Registering: " + method + " " + path + " " + name);
+
+            // All extension routes being registered must have a unique name associated with them
+            NamedRoute nr = new NamedRoute.Builder().method(method).path(path).uniqueName(name).legacyActionNames(actionNames).build();
+            restActionsAsRoutes.add(nr);
+            dynamicActionRegistry.registerDynamicRoute(nr, this);
         }
         this.routes = unmodifiableList(restActionsAsRoutes);
 
+        // TODO: Modify {@link NamedRoute} to support deprecated route registration
         List<DeprecatedRoute> restActionsAsDeprecatedRoutes = new ArrayList<>();
         // Iterate in pairs of route / deprecation message
         List<String> deprecatedActions = restActionsRequest.getDeprecatedRestActions();
diff --git a/server/src/main/java/org/opensearch/extensions/rest/RouteHandler.java b/server/src/main/java/org/opensearch/extensions/rest/RouteHandler.java
deleted file mode 100644
index 189d67c120189..0000000000000
--- a/server/src/main/java/org/opensearch/extensions/rest/RouteHandler.java
+++ /dev/null
@@ -1,69 +0,0 @@
-/*
- * SPDX-License-Identifier: Apache-2.0
- *
- * The OpenSearch Contributors require contributions made to
- * this file be licensed under the Apache-2.0 license or a
- * compatible open source license.
- */
-
-package org.opensearch.extensions.rest;
-
-import java.util.function.Function;
-
-import org.opensearch.rest.RestHandler.Route;
-import org.opensearch.rest.RestRequest;
-import org.opensearch.rest.RestRequest.Method;
-
-/**
- * A subclass of {@link Route} that includes a handler method for that route.
- */
-public class RouteHandler extends Route {
-
-    private final String name;
-
-    private final Function<RestRequest, ExtensionRestResponse> responseHandler;
-
-    /**
-     * Handle the method and path with the specified handler.
-     *
-     * @param method The {@link Method} to handle.
-     * @param path The path to handle.
-     * @param handler The method which handles the method and path.
-     */
-    public RouteHandler(Method method, String path, Function<RestRequest, ExtensionRestResponse> handler) {
-        super(method, path);
-        this.responseHandler = handler;
-        this.name = null;
-    }
-
-    /**
-     * Handle the method and path with the specified handler.
-     *
-     * @param name The name of the handler.
-     * @param method The {@link Method} to handle.
-     * @param path The path to handle.
-     * @param handler The method which handles the method and path.
-     */
-    public RouteHandler(String name, Method method, String path, Function<RestRequest, ExtensionRestResponse> handler) {
-        super(method, path);
-        this.responseHandler = handler;
-        this.name = name;
-    }
-
-    /**
-     * Executes the handler for this route.
-     *
-     * @param request The request to handle
-     * @return the {@link ExtensionRestResponse} result from the handler for this route.
-     */
-    public ExtensionRestResponse handleRequest(RestRequest request) {
-        return responseHandler.apply(request);
-    }
-
-    /**
-     * The name of the RouteHandler. Must be unique across route handlers.
-     */
-    public String name() {
-        return this.name;
-    }
-}
diff --git a/server/src/main/java/org/opensearch/index/codec/customcodecs/Lucene95CustomCodec.java b/server/src/main/java/org/opensearch/index/codec/customcodecs/Lucene95CustomCodec.java
index 3c570f9d0566c..8aa422a47a073 100644
--- a/server/src/main/java/org/opensearch/index/codec/customcodecs/Lucene95CustomCodec.java
+++ b/server/src/main/java/org/opensearch/index/codec/customcodecs/Lucene95CustomCodec.java
@@ -23,7 +23,7 @@
  * @opensearch.internal
  */
 public abstract class Lucene95CustomCodec extends FilterCodec {
-    public static final int DEFAULT_COMPRESSION_LEVEL = 6;
+    public static final int DEFAULT_COMPRESSION_LEVEL = 3;
 
     /** Each mode represents a compression algorithm. */
     public enum Mode {
diff --git a/server/src/main/java/org/opensearch/index/mapper/FlatObjectFieldMapper.java b/server/src/main/java/org/opensearch/index/mapper/FlatObjectFieldMapper.java
index e0b37df5c1734..36e0adbbf057f 100644
--- a/server/src/main/java/org/opensearch/index/mapper/FlatObjectFieldMapper.java
+++ b/server/src/main/java/org/opensearch/index/mapper/FlatObjectFieldMapper.java
@@ -85,7 +85,7 @@ public static class Defaults {
 
     @Override
     public MappedFieldType keyedFieldType(String key) {
-        return new FlatObjectFieldType(this.name() + DOT_SYMBOL + key);
+        return new FlatObjectFieldType(this.name() + DOT_SYMBOL + key, this.name());
     }
 
     /**
@@ -186,6 +186,8 @@ public static final class FlatObjectFieldType extends StringFieldType {
         private final int ignoreAbove;
         private final String nullValue;
 
+        private final String mappedFieldTypeName;
+
         private KeywordFieldMapper.KeywordFieldType valueFieldType;
 
         private KeywordFieldMapper.KeywordFieldType valueAndPathFieldType;
@@ -195,10 +197,7 @@ public FlatObjectFieldType(String name, boolean isSearchable, boolean hasDocValu
             setIndexAnalyzer(Lucene.KEYWORD_ANALYZER);
             this.ignoreAbove = Integer.MAX_VALUE;
             this.nullValue = null;
-        }
-
-        public FlatObjectFieldType(String name) {
-            this(name, true, true, Collections.emptyMap());
+            this.mappedFieldTypeName = null;
         }
 
         public FlatObjectFieldType(String name, FieldType fieldType) {
@@ -212,12 +211,28 @@ public FlatObjectFieldType(String name, FieldType fieldType) {
             );
             this.ignoreAbove = Integer.MAX_VALUE;
             this.nullValue = null;
+            this.mappedFieldTypeName = null;
         }
 
         public FlatObjectFieldType(String name, NamedAnalyzer analyzer) {
             super(name, true, false, true, new TextSearchInfo(Defaults.FIELD_TYPE, null, analyzer, analyzer), Collections.emptyMap());
             this.ignoreAbove = Integer.MAX_VALUE;
             this.nullValue = null;
+            this.mappedFieldTypeName = null;
+        }
+
+        public FlatObjectFieldType(String name, String mappedFieldTypeName) {
+            super(
+                name,
+                true,
+                false,
+                true,
+                new TextSearchInfo(Defaults.FIELD_TYPE, null, Lucene.KEYWORD_ANALYZER, Lucene.KEYWORD_ANALYZER),
+                Collections.emptyMap()
+            );
+            this.ignoreAbove = Integer.MAX_VALUE;
+            this.nullValue = null;
+            this.mappedFieldTypeName = mappedFieldTypeName;
         }
 
         void setValueFieldType(KeywordFieldMapper.KeywordFieldType valueFieldType) {
@@ -356,22 +371,21 @@ public Query termsQuery(List<?> values, QueryShardContext context) {
          * @return directedSubFieldName
          */
         public String directSubfield() {
-            if (name().contains(DOT_SYMBOL)) {
-                String[] dotPathList = name().split("\\.");
-                return dotPathList[0] + VALUE_AND_PATH_SUFFIX;
+            if (mappedFieldTypeName == null) {
+                return new StringBuilder().append(this.name()).append(VALUE_SUFFIX).toString();
             } else {
-                return this.valueFieldType.name();
+                return new StringBuilder().append(this.mappedFieldTypeName).append(VALUE_AND_PATH_SUFFIX).toString();
             }
         }
 
         /**
-         * If the search key is assigned with value,
-         * the dot path was used in search query, then
-         * rewrite the searchValueString as the format "dotpath=value",
+         * If the search key has mappedFieldTypeName as prefix,
+         * then the dot path was used in search query,
+         * then rewrite the searchValueString as the format "dotpath=value",
          * @return rewriteSearchValue
          */
         public String rewriteValue(String searchValueString) {
-            if (!name().contains(DOT_SYMBOL)) {
+            if (!hasMappedFieldTyeNameInQueryFieldName(name())) {
                 return searchValueString;
             } else {
                 String rewriteSearchValue = new StringBuilder().append(name()).append(EQUAL_SYMBOL).append(searchValueString).toString();
@@ -380,6 +394,23 @@ public String rewriteValue(String searchValueString) {
 
         }
 
+        private boolean hasMappedFieldTyeNameInQueryFieldName(String input) {
+            String prefix = this.mappedFieldTypeName;
+            if (prefix == null) {
+                return false;
+            }
+            if (!input.startsWith(prefix)) {
+                return false;
+            }
+            String rest = input.substring(prefix.length());
+
+            if (rest.isEmpty()) {
+                return false;
+            } else {
+                return true;
+            }
+        }
+
         private String inputToString(Object inputValue) {
             if (inputValue instanceof Integer) {
                 String inputToString = Integer.toString((Integer) inputValue);
@@ -460,15 +491,15 @@ public Query rangeQuery(Object lowerTerm, Object upperTerm, boolean includeLower
         }
 
         /**
-         * if there is dot path. query the field name in flatObject parent field.
+         * if there is dot path. query the field name in flatObject parent field (mappedFieldTypeName).
          * else query in _field_names system field
          */
         @Override
         public Query existsQuery(QueryShardContext context) {
             String searchKey;
             String searchField;
-            if (name().contains(DOT_SYMBOL)) {
-                searchKey = name().split("\\.")[0];
+            if (hasMappedFieldTyeNameInQueryFieldName(name())) {
+                searchKey = this.mappedFieldTypeName;
                 searchField = name();
             } else {
                 searchKey = FieldNamesFieldMapper.NAME;
diff --git a/server/src/main/java/org/opensearch/index/remote/RemoteStoreUtils.java b/server/src/main/java/org/opensearch/index/remote/RemoteStoreUtils.java
new file mode 100644
index 0000000000000..1eeadfe228a45
--- /dev/null
+++ b/server/src/main/java/org/opensearch/index/remote/RemoteStoreUtils.java
@@ -0,0 +1,51 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.index.remote;
+
+import java.util.Arrays;
+
+/**
+ * Utils for remote store
+ *
+ * @opensearch.internal
+ */
+public class RemoteStoreUtils {
+    public static final int LONG_MAX_LENGTH = String.valueOf(Long.MAX_VALUE).length();
+
+    /**
+     * This method subtracts given numbers from Long.MAX_VALUE and returns a string representation of the result.
+     * The resultant string is guaranteed to be of the same length that of Long.MAX_VALUE. If shorter, we add left padding
+     * of 0s to the string.
+     * @param num number to get the inverted long string for
+     * @return String value of Long.MAX_VALUE - num
+     */
+    public static String invertLong(long num) {
+        if (num < 0) {
+            throw new IllegalArgumentException("Negative long values are not allowed");
+        }
+        String invertedLong = String.valueOf(Long.MAX_VALUE - num);
+        char[] characterArray = new char[LONG_MAX_LENGTH - invertedLong.length()];
+        Arrays.fill(characterArray, '0');
+
+        return new String(characterArray) + invertedLong;
+    }
+
+    /**
+     * This method converts the given string into long and subtracts it from Long.MAX_VALUE
+     * @param str long in string format to be inverted
+     * @return long value of the invert result
+     */
+    public static long invertLong(String str) {
+        long num = Long.parseLong(str);
+        if (num < 0) {
+            throw new IllegalArgumentException("Strings representing negative long values are not allowed");
+        }
+        return Long.MAX_VALUE - num;
+    }
+}
diff --git a/server/src/main/java/org/opensearch/index/shard/IndexShard.java b/server/src/main/java/org/opensearch/index/shard/IndexShard.java
index c2bbead2d9430..80478264049c6 100644
--- a/server/src/main/java/org/opensearch/index/shard/IndexShard.java
+++ b/server/src/main/java/org/opensearch/index/shard/IndexShard.java
@@ -2632,7 +2632,7 @@ public void restoreFromSnapshotAndRemoteStore(
             assert recoveryState.getRecoverySource().getType() == RecoverySource.Type.SNAPSHOT : "invalid recovery type: "
                 + recoveryState.getRecoverySource();
             StoreRecovery storeRecovery = new StoreRecovery(shardId, logger);
-            storeRecovery.recoverFromSnapshotAndRemoteStore(this, repository, repositoriesService, listener);
+            storeRecovery.recoverFromSnapshotAndRemoteStore(this, repository, repositoriesService, listener, threadPool);
         } catch (Exception e) {
             listener.onFailure(e);
         }
diff --git a/server/src/main/java/org/opensearch/index/shard/RemoteStoreRefreshListener.java b/server/src/main/java/org/opensearch/index/shard/RemoteStoreRefreshListener.java
index f3b82b40faa6f..af86a108a670b 100644
--- a/server/src/main/java/org/opensearch/index/shard/RemoteStoreRefreshListener.java
+++ b/server/src/main/java/org/opensearch/index/shard/RemoteStoreRefreshListener.java
@@ -30,6 +30,7 @@
 import org.opensearch.index.seqno.SequenceNumbers;
 import org.opensearch.index.store.RemoteSegmentStoreDirectory;
 import org.opensearch.index.store.remote.metadata.RemoteSegmentMetadata;
+import org.opensearch.index.translog.Translog;
 import org.opensearch.indices.replication.checkpoint.ReplicationCheckpoint;
 import org.opensearch.indices.replication.checkpoint.SegmentReplicationCheckpointPublisher;
 import org.opensearch.threadpool.Scheduler;
@@ -85,7 +86,7 @@ public final class RemoteStoreRefreshListener implements ReferenceManager.Refres
     // Visible for testing
     static final Set<String> EXCLUDE_FILES = Set.of("write.lock");
     // Visible for testing
-    static final int LAST_N_METADATA_FILES_TO_KEEP = 10;
+    public static final int LAST_N_METADATA_FILES_TO_KEEP = 10;
 
     private final IndexShard indexShard;
     private final Directory storeDirectory;
@@ -202,9 +203,8 @@ private synchronized void syncSegments(boolean isRetry) {
                 // if a new segments_N file is present in local that is not uploaded to remote store yet, it
                 // is considered as a first refresh post commit. A cleanup of stale commit files is triggered.
                 // This is done to avoid delete post each refresh.
-                // Ideally, we want this to be done in async flow. (GitHub issue #4315)
                 if (isRefreshAfterCommit()) {
-                    deleteStaleCommits();
+                    remoteDirectory.deleteStaleSegmentsAsync(LAST_N_METADATA_FILES_TO_KEEP);
                 }
 
                 try (GatedCloseable<SegmentInfos> segmentInfosGatedCloseable = indexShard.getSegmentInfosSnapshot()) {
@@ -226,7 +226,17 @@ private synchronized void syncSegments(boolean isRetry) {
                         // Each metadata file in the remote segment store represents a commit and the following
                         // statement keeps sure that each metadata will always contain all the segments from last commit + refreshed
                         // segments.
-                        localSegmentsPostRefresh.addAll(SegmentInfos.readCommit(storeDirectory, latestSegmentInfos.get()).files(true));
+                        SegmentInfos segmentCommitInfos;
+                        try {
+                            segmentCommitInfos = SegmentInfos.readCommit(storeDirectory, latestSegmentInfos.get());
+                        } catch (Exception e) {
+                            // Seeing discrepancy in segment infos and files on disk. SegmentInfosSnapshot is returning
+                            // a segment_N file which does not exist on local disk.
+                            logger.error("Exception occurred while SegmentInfos.readCommit(..)", e);
+                            logger.error("segmentInfosFiles={} diskFiles={}", localSegmentsPostRefresh, storeDirectory.listAll());
+                            throw e;
+                        }
+                        localSegmentsPostRefresh.addAll(segmentCommitInfos.files(true));
                         segmentInfosFiles.stream()
                             .filter(file -> !file.equals(latestSegmentInfos.get()))
                             .forEach(localSegmentsPostRefresh::remove);
@@ -351,12 +361,19 @@ void uploadMetadata(Collection<String> localSegmentsPostRefresh, SegmentInfos se
         userData.put(SequenceNumbers.MAX_SEQ_NO, Long.toString(maxSeqNo));
         segmentInfosSnapshot.setUserData(userData, false);
 
-        remoteDirectory.uploadMetadata(
-            localSegmentsPostRefresh,
-            segmentInfosSnapshot,
-            storeDirectory,
-            indexShard.getOperationPrimaryTerm()
-        );
+        Translog.TranslogGeneration translogGeneration = indexShard.getEngine().translogManager().getTranslogGeneration();
+        if (translogGeneration == null) {
+            throw new UnsupportedOperationException("Encountered null TranslogGeneration while uploading metadata to remote segment store");
+        } else {
+            long translogFileGeneration = translogGeneration.translogFileGeneration;
+            remoteDirectory.uploadMetadata(
+                localSegmentsPostRefresh,
+                segmentInfosSnapshot,
+                storeDirectory,
+                indexShard.getOperationPrimaryTerm(),
+                translogFileGeneration
+            );
+        }
     }
 
     private boolean uploadNewSegments(Collection<String> localSegmentsPostRefresh) throws IOException {
@@ -382,14 +399,6 @@ private String getChecksumOfLocalFile(String file) throws IOException {
         return localSegmentChecksumMap.get(file);
     }
 
-    private void deleteStaleCommits() {
-        try {
-            remoteDirectory.deleteStaleSegments(LAST_N_METADATA_FILES_TO_KEEP);
-        } catch (IOException e) {
-            logger.info("Exception while deleting stale commits from remote segment store, will retry delete post next commit", e);
-        }
-    }
-
     /**
      * Updates the last refresh time and refresh seq no which is seen by local store.
      */
diff --git a/server/src/main/java/org/opensearch/index/shard/StoreRecovery.java b/server/src/main/java/org/opensearch/index/shard/StoreRecovery.java
index 119524e8caf8a..da4e9113143af 100644
--- a/server/src/main/java/org/opensearch/index/shard/StoreRecovery.java
+++ b/server/src/main/java/org/opensearch/index/shard/StoreRecovery.java
@@ -69,6 +69,7 @@
 import org.opensearch.repositories.IndexId;
 import org.opensearch.repositories.RepositoriesService;
 import org.opensearch.repositories.Repository;
+import org.opensearch.threadpool.ThreadPool;
 
 import java.io.IOException;
 import java.nio.channels.FileChannel;
@@ -356,7 +357,8 @@ void recoverFromSnapshotAndRemoteStore(
         final IndexShard indexShard,
         Repository repository,
         RepositoriesService repositoriesService,
-        ActionListener<Boolean> listener
+        ActionListener<Boolean> listener,
+        ThreadPool threadPool
     ) {
         try {
             if (canRecover(indexShard)) {
@@ -384,7 +386,10 @@ void recoverFromSnapshotAndRemoteStore(
                     remoteStoreRepository = shallowCopyShardMetadata.getRemoteStoreRepository();
                 }
 
-                RemoteSegmentStoreDirectoryFactory directoryFactory = new RemoteSegmentStoreDirectoryFactory(() -> repositoriesService);
+                RemoteSegmentStoreDirectoryFactory directoryFactory = new RemoteSegmentStoreDirectoryFactory(
+                    () -> repositoriesService,
+                    threadPool
+                );
                 RemoteSegmentStoreDirectory sourceRemoteDirectory = (RemoteSegmentStoreDirectory) directoryFactory.newDirectory(
                     remoteStoreRepository,
                     indexUUID,
diff --git a/server/src/main/java/org/opensearch/index/snapshots/blobstore/RemoteStoreShardShallowCopySnapshot.java b/server/src/main/java/org/opensearch/index/snapshots/blobstore/RemoteStoreShardShallowCopySnapshot.java
index 8e6ed870c904f..8cb9fd3cd3c63 100644
--- a/server/src/main/java/org/opensearch/index/snapshots/blobstore/RemoteStoreShardShallowCopySnapshot.java
+++ b/server/src/main/java/org/opensearch/index/snapshots/blobstore/RemoteStoreShardShallowCopySnapshot.java
@@ -408,4 +408,29 @@ private void verifyParameters(
             throw new IllegalArgumentException(exceptionStr);
         }
     }
+
+    /**
+     * Creates a new instance which has a different name and zero incremental file counts but is identical to this instance in terms of the files
+     * it references.
+     *
+     * @param targetSnapshotName target snapshot name
+     * @param startTime          time the clone operation on the repository was started
+     * @param time               time it took to create the clone
+     */
+    public RemoteStoreShardShallowCopySnapshot asClone(String targetSnapshotName, long startTime, long time) {
+        return new RemoteStoreShardShallowCopySnapshot(
+            targetSnapshotName,
+            indexVersion,
+            primaryTerm,
+            commitGeneration,
+            startTime,
+            time,
+            totalFileCount,
+            totalSize,
+            indexUUID,
+            remoteStoreRepository,
+            repositoryBasePath,
+            fileNames
+        );
+    }
 }
diff --git a/server/src/main/java/org/opensearch/index/store/RemoteDirectory.java b/server/src/main/java/org/opensearch/index/store/RemoteDirectory.java
index be4b4e910bb4d..8782808c070ab 100644
--- a/server/src/main/java/org/opensearch/index/store/RemoteDirectory.java
+++ b/server/src/main/java/org/opensearch/index/store/RemoteDirectory.java
@@ -13,6 +13,8 @@
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.store.Lock;
+import org.opensearch.action.ActionListener;
+import org.opensearch.action.LatchedActionListener;
 import org.opensearch.common.blobstore.BlobContainer;
 import org.opensearch.common.blobstore.BlobMetadata;
 
@@ -20,10 +22,15 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.file.NoSuchFileException;
+import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.stream.Collectors;
 
 /**
  * A {@code RemoteDirectory} provides an abstraction layer for storing a list of files to a remote store.
@@ -61,6 +68,40 @@ public Collection<String> listFilesByPrefix(String filenamePrefix) throws IOExce
         return blobContainer.listBlobsByPrefix(filenamePrefix).keySet();
     }
 
+    public List<String> listFilesByPrefixInLexicographicOrder(String filenamePrefix, int limit) throws IOException {
+        List<String> sortedBlobList = new ArrayList<>();
+        AtomicReference<Exception> exception = new AtomicReference<>();
+        final CountDownLatch latch = new CountDownLatch(1);
+        LatchedActionListener<List<BlobMetadata>> actionListener = new LatchedActionListener<>(new ActionListener<>() {
+            @Override
+            public void onResponse(List<BlobMetadata> blobMetadata) {
+                sortedBlobList.addAll(blobMetadata.stream().map(BlobMetadata::name).collect(Collectors.toList()));
+            }
+
+            @Override
+            public void onFailure(Exception e) {
+                exception.set(e);
+            }
+        }, latch);
+
+        try {
+            blobContainer.listBlobsByPrefixInSortedOrder(
+                filenamePrefix,
+                limit,
+                BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC,
+                actionListener
+            );
+            latch.await();
+        } catch (InterruptedException e) {
+            throw new IOException("Exception in listFilesByPrefixInLexicographicOrder with prefix: " + filenamePrefix, e);
+        }
+        if (exception.get() != null) {
+            throw new IOException(exception.get());
+        } else {
+            return sortedBlobList;
+        }
+    }
+
     /**
      * Removes an existing file in the directory.
      *
diff --git a/server/src/main/java/org/opensearch/index/store/RemoteSegmentStoreDirectory.java b/server/src/main/java/org/opensearch/index/store/RemoteSegmentStoreDirectory.java
index addd8a24af9c5..e7602203440d2 100644
--- a/server/src/main/java/org/opensearch/index/store/RemoteSegmentStoreDirectory.java
+++ b/server/src/main/java/org/opensearch/index/store/RemoteSegmentStoreDirectory.java
@@ -22,26 +22,27 @@
 import org.opensearch.common.UUIDs;
 import org.opensearch.common.io.VersionedCodecStreamWrapper;
 import org.opensearch.common.lucene.store.ByteArrayIndexInput;
+import org.opensearch.index.remote.RemoteStoreUtils;
 import org.opensearch.index.store.lockmanager.FileLockInfo;
 import org.opensearch.index.store.lockmanager.RemoteStoreCommitLevelLockManager;
 import org.opensearch.index.store.lockmanager.RemoteStoreLockManager;
 import org.opensearch.index.store.remote.metadata.RemoteSegmentMetadata;
 import org.opensearch.index.store.remote.metadata.RemoteSegmentMetadataHandler;
+import org.opensearch.threadpool.ThreadPool;
 
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.nio.file.NoSuchFileException;
 import java.util.Collection;
 import java.util.Collections;
-import java.util.Comparator;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
-import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicLong;
 import java.util.stream.Collectors;
 
 /**
@@ -61,9 +62,6 @@ public final class RemoteSegmentStoreDirectory extends FilterDirectory implement
      */
     public static final String SEGMENT_NAME_UUID_SEPARATOR = "__";
 
-    public static final MetadataFilenameUtils.MetadataFilenameComparator METADATA_FILENAME_COMPARATOR =
-        new MetadataFilenameUtils.MetadataFilenameComparator();
-
     /**
      * remoteDataDirectory is used to store segment files at path: cluster_UUID/index_UUID/shardId/segments/data
      */
@@ -75,11 +73,7 @@ public final class RemoteSegmentStoreDirectory extends FilterDirectory implement
 
     private final RemoteStoreLockManager mdLockManager;
 
-    /**
-     * To prevent explosion of refresh metadata files, we replace refresh files for the given primary term and generation
-     * This is achieved by uploading refresh metadata file with the same UUID suffix.
-     */
-    private String commonFilenameSuffix;
+    private final ThreadPool threadPool;
 
     /**
      * Keeps track of local segment filename to uploaded filename along with other attributes like checksum.
@@ -96,15 +90,25 @@ public final class RemoteSegmentStoreDirectory extends FilterDirectory implement
 
     private static final Logger logger = LogManager.getLogger(RemoteSegmentStoreDirectory.class);
 
+    /**
+     * AtomicBoolean that ensures only one staleCommitDeletion activity is scheduled at a time.
+     * Visible for testing
+     */
+    protected final AtomicBoolean canDeleteStaleCommits = new AtomicBoolean(true);
+
+    private final AtomicLong metadataUploadCounter = new AtomicLong(0);
+
     public RemoteSegmentStoreDirectory(
         RemoteDirectory remoteDataDirectory,
         RemoteDirectory remoteMetadataDirectory,
-        RemoteStoreLockManager mdLockManager
+        RemoteStoreLockManager mdLockManager,
+        ThreadPool threadPool
     ) throws IOException {
         super(remoteDataDirectory);
         this.remoteDataDirectory = remoteDataDirectory;
         this.remoteMetadataDirectory = remoteMetadataDirectory;
         this.mdLockManager = mdLockManager;
+        this.threadPool = threadPool;
         init();
     }
 
@@ -116,7 +120,6 @@ public RemoteSegmentStoreDirectory(
      * @throws IOException if there were any failures in reading the metadata file
      */
     public RemoteSegmentMetadata init() throws IOException {
-        this.commonFilenameSuffix = UUIDs.base64UUID();
         RemoteSegmentMetadata remoteSegmentMetadata = readLatestMetadataFile();
         if (remoteSegmentMetadata != null) {
             this.segmentsUploadedToRemoteStore = new ConcurrentHashMap<>(remoteSegmentMetadata.getMetadata());
@@ -159,12 +162,15 @@ public RemoteSegmentMetadata initializeToSpecificCommit(long primaryTerm, long c
     public RemoteSegmentMetadata readLatestMetadataFile() throws IOException {
         RemoteSegmentMetadata remoteSegmentMetadata = null;
 
-        Collection<String> metadataFiles = remoteMetadataDirectory.listFilesByPrefix(MetadataFilenameUtils.METADATA_PREFIX);
-        Optional<String> latestMetadataFile = metadataFiles.stream().max(METADATA_FILENAME_COMPARATOR);
+        List<String> metadataFiles = remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
+            MetadataFilenameUtils.METADATA_PREFIX,
+            1
+        );
 
-        if (latestMetadataFile.isPresent()) {
-            logger.info("Reading latest Metadata file {}", latestMetadataFile.get());
-            remoteSegmentMetadata = readMetadataFile(latestMetadataFile.get());
+        if (metadataFiles.isEmpty() == false) {
+            String latestMetadataFile = metadataFiles.get(0);
+            logger.info("Reading latest Metadata file {}", latestMetadataFile);
+            remoteSegmentMetadata = readMetadataFile(latestMetadataFile);
         } else {
             logger.info("No metadata file found, this can happen for new index with no data uploaded to remote segment store");
         }
@@ -176,8 +182,7 @@ private RemoteSegmentMetadata readMetadataFile(String metadataFilename) throws I
         try (IndexInput indexInput = remoteMetadataDirectory.openInput(metadataFilename, IOContext.DEFAULT)) {
             byte[] metadataBytes = new byte[(int) indexInput.length()];
             indexInput.readBytes(metadataBytes, 0, (int) indexInput.length());
-            RemoteSegmentMetadata metadata = metadataStreamWrapper.readStream(new ByteArrayIndexInput(metadataFilename, metadataBytes));
-            return metadata;
+            return metadataStreamWrapper.readStream(new ByteArrayIndexInput(metadataFilename, metadataBytes));
         }
     }
 
@@ -231,56 +236,43 @@ static class MetadataFilenameUtils {
         public static final String SEPARATOR = "__";
         public static final String METADATA_PREFIX = "metadata";
 
-        /**
-         * Comparator to sort the metadata filenames. The order of sorting is: Primary Term, Generation, UUID
-         * Even though UUID sort does not provide any info on recency, it provides a consistent way to sort the filenames.
-         */
-        static class MetadataFilenameComparator implements Comparator<String> {
-            @Override
-            public int compare(String first, String second) {
-                String[] firstTokens = first.split(SEPARATOR);
-                String[] secondTokens = second.split(SEPARATOR);
-                if (!firstTokens[0].equals(secondTokens[0])) {
-                    return firstTokens[0].compareTo(secondTokens[0]);
-                }
-                long firstPrimaryTerm = getPrimaryTerm(firstTokens);
-                long secondPrimaryTerm = getPrimaryTerm(secondTokens);
-                if (firstPrimaryTerm != secondPrimaryTerm) {
-                    return firstPrimaryTerm > secondPrimaryTerm ? 1 : -1;
-                } else {
-                    long firstGeneration = getGeneration(firstTokens);
-                    long secondGeneration = getGeneration(secondTokens);
-                    if (firstGeneration != secondGeneration) {
-                        return firstGeneration > secondGeneration ? 1 : -1;
-                    } else {
-                        return getUuid(firstTokens).compareTo(getUuid(secondTokens));
-                    }
-                }
-            }
-        }
-
         static String getMetadataFilePrefixForCommit(long primaryTerm, long generation) {
-            return String.join(SEPARATOR, METADATA_PREFIX, Long.toString(primaryTerm), Long.toString(generation, Character.MAX_RADIX));
+            return String.join(
+                SEPARATOR,
+                METADATA_PREFIX,
+                RemoteStoreUtils.invertLong(primaryTerm),
+                RemoteStoreUtils.invertLong(generation)
+            );
         }
 
         // Visible for testing
-        static String getMetadataFilename(long primaryTerm, long generation, String uuid) {
-            return String.join(SEPARATOR, getMetadataFilePrefixForCommit(primaryTerm, generation), uuid);
+        static String getMetadataFilename(
+            long primaryTerm,
+            long generation,
+            long translogGeneration,
+            long uploadCounter,
+            int metadataVersion
+        ) {
+            return String.join(
+                SEPARATOR,
+                METADATA_PREFIX,
+                RemoteStoreUtils.invertLong(primaryTerm),
+                RemoteStoreUtils.invertLong(generation),
+                RemoteStoreUtils.invertLong(translogGeneration),
+                RemoteStoreUtils.invertLong(uploadCounter),
+                RemoteStoreUtils.invertLong(System.currentTimeMillis()),
+                String.valueOf(metadataVersion)
+            );
         }
 
         // Visible for testing
         static long getPrimaryTerm(String[] filenameTokens) {
-            return Long.parseLong(filenameTokens[1]);
+            return RemoteStoreUtils.invertLong(filenameTokens[1]);
         }
 
         // Visible for testing
         static long getGeneration(String[] filenameTokens) {
-            return Long.parseLong(filenameTokens[2], Character.MAX_RADIX);
-        }
-
-        // Visible for testing
-        static String getUuid(String[] filenameTokens) {
-            return filenameTokens[3];
+            return RemoteStoreUtils.invertLong(filenameTokens[2]);
         }
     }
 
@@ -368,7 +360,6 @@ public IndexInput openInput(String name, IOContext context) throws IOException {
     @Override
     public void acquireLock(long primaryTerm, long generation, String acquirerId) throws IOException {
         String metadataFile = getMetadataFileForCommit(primaryTerm, generation);
-
         mdLockManager.acquire(FileLockInfo.getLockInfoBuilder().withFileToLock(metadataFile).withAcquirerId(acquirerId).build());
     }
 
@@ -397,13 +388,19 @@ public void releaseLock(long primaryTerm, long generation, String acquirerId) th
     @Override
     public Boolean isLockAcquired(long primaryTerm, long generation) throws IOException {
         String metadataFile = getMetadataFileForCommit(primaryTerm, generation);
+        return isLockAcquired(metadataFile);
+    }
+
+    // Visible for testing
+    Boolean isLockAcquired(String metadataFile) throws IOException {
         return mdLockManager.isAcquired(FileLockInfo.getLockInfoBuilder().withFileToLock(metadataFile).build());
     }
 
     // Visible for testing
     String getMetadataFileForCommit(long primaryTerm, long generation) throws IOException {
-        Collection<String> metadataFiles = remoteMetadataDirectory.listFilesByPrefix(
-            MetadataFilenameUtils.getMetadataFilePrefixForCommit(primaryTerm, generation)
+        List<String> metadataFiles = remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
+            MetadataFilenameUtils.getMetadataFilePrefixForCommit(primaryTerm, generation),
+            1
         );
 
         if (metadataFiles.isEmpty()) {
@@ -421,33 +418,24 @@ String getMetadataFileForCommit(long primaryTerm, long generation) throws IOExce
                     + metadataFiles.size()
             );
         }
-        return metadataFiles.iterator().next();
+        return metadataFiles.get(0);
     }
 
-    public void copyFrom(Directory from, String src, String dest, IOContext context, boolean useCommonSuffix, String checksum)
-        throws IOException {
+    public void copyFrom(Directory from, String src, String dest, IOContext context, String checksum) throws IOException {
         String remoteFilename;
-        if (useCommonSuffix) {
-            remoteFilename = dest + SEGMENT_NAME_UUID_SEPARATOR + this.commonFilenameSuffix;
-        } else {
-            remoteFilename = getNewRemoteSegmentFilename(dest);
-        }
+        remoteFilename = getNewRemoteSegmentFilename(dest);
         remoteDataDirectory.copyFrom(from, src, remoteFilename, context);
         UploadedSegmentMetadata segmentMetadata = new UploadedSegmentMetadata(src, remoteFilename, checksum, from.fileLength(src));
         segmentsUploadedToRemoteStore.put(src, segmentMetadata);
     }
 
-    public void copyFrom(Directory from, String src, String dest, IOContext context, boolean useCommonSuffix) throws IOException {
-        copyFrom(from, src, dest, context, useCommonSuffix, getChecksumOfLocalFile(from, src));
-    }
-
     /**
      * Copies an existing src file from directory from to a non-existent file dest in this directory.
      * Once the segment is uploaded to remote segment store, update the cache accordingly.
      */
     @Override
     public void copyFrom(Directory from, String src, String dest, IOContext context) throws IOException {
-        copyFrom(from, src, dest, context, false);
+        copyFrom(from, src, dest, context, getChecksumOfLocalFile(from, src));
     }
 
     /**
@@ -475,13 +463,16 @@ public void uploadMetadata(
         Collection<String> segmentFiles,
         SegmentInfos segmentInfosSnapshot,
         Directory storeDirectory,
-        long primaryTerm
+        long primaryTerm,
+        long translogGeneration
     ) throws IOException {
         synchronized (this) {
             String metadataFilename = MetadataFilenameUtils.getMetadataFilename(
                 primaryTerm,
                 segmentInfosSnapshot.getGeneration(),
-                this.commonFilenameSuffix
+                translogGeneration,
+                metadataUploadCounter.incrementAndGet(),
+                RemoteSegmentMetadata.CURRENT_VERSION
             );
             try {
                 IndexOutput indexOutput = storeDirectory.createOutput(metadataFilename, IOContext.DEFAULT);
@@ -558,15 +549,6 @@ public Map<String, UploadedSegmentMetadata> getSegmentsUploadedToRemoteStore() {
         return Collections.unmodifiableMap(this.segmentsUploadedToRemoteStore);
     }
 
-    public Map<String, UploadedSegmentMetadata> getSegmentsUploadedToRemoteStore(long primaryTerm, long generation) throws IOException {
-        String metadataFile = getMetadataFileForCommit(primaryTerm, generation);
-
-        Map<String, UploadedSegmentMetadata> segmentsUploadedToRemoteStore = new ConcurrentHashMap<>(
-            readMetadataFile(metadataFile).getMetadata()
-        );
-        return Collections.unmodifiableMap(segmentsUploadedToRemoteStore);
-    }
-
     /**
      * Delete stale segment and metadata files
      * One metadata file is kept per commit (refresh updates the same file). To read segments uploaded to remote store,
@@ -575,8 +557,10 @@ public Map<String, UploadedSegmentMetadata> getSegmentsUploadedToRemoteStore(lon
      * @throws IOException in case of I/O error while reading from / writing to remote segment store
      */
     public void deleteStaleSegments(int lastNMetadataFilesToKeep) throws IOException {
-        Collection<String> metadataFiles = remoteMetadataDirectory.listFilesByPrefix(MetadataFilenameUtils.METADATA_PREFIX);
-        List<String> sortedMetadataFileList = metadataFiles.stream().sorted(METADATA_FILENAME_COMPARATOR).collect(Collectors.toList());
+        List<String> sortedMetadataFileList = remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
+            MetadataFilenameUtils.METADATA_PREFIX,
+            Integer.MAX_VALUE
+        );
         if (sortedMetadataFileList.size() <= lastNMetadataFilesToKeep) {
             logger.info(
                 "Number of commits in remote segment store={}, lastNMetadataFilesToKeep={}",
@@ -587,21 +571,12 @@ public void deleteStaleSegments(int lastNMetadataFilesToKeep) throws IOException
         }
 
         List<String> metadataFilesEligibleToDelete = sortedMetadataFileList.subList(
-            0,
-            sortedMetadataFileList.size() - lastNMetadataFilesToKeep
+            lastNMetadataFilesToKeep,
+            sortedMetadataFileList.size()
         );
         List<String> metadataFilesToBeDeleted = metadataFilesEligibleToDelete.stream().filter(metadataFile -> {
             try {
-                // TODO: add snapshot interop feature flag here as that will be the first feature to use lock
-                // manager.
-                boolean lockManagerEnabled = false;
-                if (!lockManagerEnabled) {
-                    return true;
-                }
-                return !isLockAcquired(
-                    MetadataFilenameUtils.getPrimaryTerm(metadataFile.split(MetadataFilenameUtils.SEPARATOR)),
-                    MetadataFilenameUtils.getGeneration(metadataFile.split(MetadataFilenameUtils.SEPARATOR))
-                );
+                return !isLockAcquired(metadataFile);
             } catch (IOException e) {
                 logger.error(
                     "skipping metadata file ("
@@ -656,12 +631,42 @@ public void deleteStaleSegments(int lastNMetadataFilesToKeep) throws IOException
         }
     }
 
+    /**
+     * Delete stale segment and metadata files asynchronously.
+     * This method calls {@link RemoteSegmentStoreDirectory#deleteStaleSegments(int)} in an async manner.
+     * @param lastNMetadataFilesToKeep number of metadata files to keep
+     */
+    public void deleteStaleSegmentsAsync(int lastNMetadataFilesToKeep) {
+        if (canDeleteStaleCommits.compareAndSet(true, false)) {
+            try {
+                threadPool.executor(ThreadPool.Names.REMOTE_PURGE).execute(() -> {
+                    try {
+                        deleteStaleSegments(lastNMetadataFilesToKeep);
+                    } catch (Exception e) {
+                        logger.info(
+                            "Exception while deleting stale commits from remote segment store, will retry delete post next commit",
+                            e
+                        );
+                    } finally {
+                        canDeleteStaleCommits.set(true);
+                    }
+                });
+            } catch (Exception e) {
+                logger.info("Exception occurred while scheduling deleteStaleCommits", e);
+                canDeleteStaleCommits.set(true);
+            }
+        }
+    }
+
     /*
     Tries to delete shard level directory if it is empty
     Return true if it deleted it successfully
      */
     private boolean deleteIfEmpty() throws IOException {
-        Collection<String> metadataFiles = remoteMetadataDirectory.listFilesByPrefix(MetadataFilenameUtils.METADATA_PREFIX);
+        Collection<String> metadataFiles = remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
+            MetadataFilenameUtils.METADATA_PREFIX,
+            1
+        );
         if (metadataFiles.size() != 0) {
             logger.info("Remote directory still has files , not deleting the path");
             return false;
@@ -680,7 +685,7 @@ private boolean deleteIfEmpty() throws IOException {
     }
 
     public void close() throws IOException {
-        deleteStaleSegments(0);
+        deleteStaleSegmentsAsync(0);
         deleteIfEmpty();
     }
 }
diff --git a/server/src/main/java/org/opensearch/index/store/RemoteSegmentStoreDirectoryFactory.java b/server/src/main/java/org/opensearch/index/store/RemoteSegmentStoreDirectoryFactory.java
index 03995d5913fb3..3bec84f287ce4 100644
--- a/server/src/main/java/org/opensearch/index/store/RemoteSegmentStoreDirectoryFactory.java
+++ b/server/src/main/java/org/opensearch/index/store/RemoteSegmentStoreDirectoryFactory.java
@@ -20,6 +20,7 @@
 import org.opensearch.repositories.Repository;
 import org.opensearch.repositories.RepositoryMissingException;
 import org.opensearch.repositories.blobstore.BlobStoreRepository;
+import org.opensearch.threadpool.ThreadPool;
 
 import java.io.IOException;
 import java.util.function.Supplier;
@@ -34,8 +35,11 @@ public class RemoteSegmentStoreDirectoryFactory implements IndexStorePlugin.Dire
 
     private final Supplier<RepositoriesService> repositoriesService;
 
-    public RemoteSegmentStoreDirectoryFactory(Supplier<RepositoriesService> repositoriesService) {
+    private final ThreadPool threadPool;
+
+    public RemoteSegmentStoreDirectoryFactory(Supplier<RepositoriesService> repositoriesService, ThreadPool threadPool) {
         this.repositoriesService = repositoriesService;
+        this.threadPool = threadPool;
     }
 
     @Override
@@ -62,7 +66,7 @@ public Directory newDirectory(String repositoryName, String indexUUID, String sh
                 shardId
             );
 
-            return new RemoteSegmentStoreDirectory(dataDirectory, metadataDirectory, mdLockManager);
+            return new RemoteSegmentStoreDirectory(dataDirectory, metadataDirectory, mdLockManager, threadPool);
         } catch (RepositoryMissingException e) {
             throw new IllegalArgumentException("Repository should be created before creating index with remote_store enabled setting", e);
         }
diff --git a/server/src/main/java/org/opensearch/index/store/lockmanager/FileLockInfo.java b/server/src/main/java/org/opensearch/index/store/lockmanager/FileLockInfo.java
index a8fb7bf20c393..24f42743e1a04 100644
--- a/server/src/main/java/org/opensearch/index/store/lockmanager/FileLockInfo.java
+++ b/server/src/main/java/org/opensearch/index/store/lockmanager/FileLockInfo.java
@@ -8,6 +8,7 @@
 
 package org.opensearch.index.store.lockmanager;
 
+import java.nio.file.NoSuchFileException;
 import java.util.Arrays;
 import java.util.List;
 import java.util.stream.Collectors;
@@ -50,13 +51,21 @@ String getLockPrefix() {
         return fileToLock + RemoteStoreLockManagerUtils.SEPARATOR;
     }
 
-    List<String> getLocksForAcquirer(String[] lockFiles) {
+    String getLockForAcquirer(String[] lockFiles) throws NoSuchFileException {
         if (acquirerId == null || acquirerId.isBlank()) {
             throw new IllegalArgumentException("Acquirer ID should be provided");
         }
-        return Arrays.stream(lockFiles)
+        List<String> locksForAcquirer = Arrays.stream(lockFiles)
             .filter(lockFile -> acquirerId.equals(LockFileUtils.getAcquirerIdFromLock(lockFile)))
             .collect(Collectors.toList());
+
+        if (locksForAcquirer.isEmpty()) {
+            throw new NoSuchFileException("No lock file found for the acquirer: " + acquirerId);
+        }
+        if (locksForAcquirer.size() != 1) {
+            throw new IllegalStateException("Expected single lock file but found [" + locksForAcquirer.size() + "] lock files");
+        }
+        return locksForAcquirer.get(0);
     }
 
     public static LockInfoBuilder getLockInfoBuilder() {
diff --git a/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreLockManager.java b/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreLockManager.java
index c30be082b4795..9eb066d9e955e 100644
--- a/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreLockManager.java
+++ b/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreLockManager.java
@@ -39,6 +39,16 @@ public interface RemoteStoreLockManager {
      */
     Boolean isAcquired(LockInfo lockInfo) throws IOException;
 
+    /**
+     * Acquires lock on the file mentioned in originalLockInfo for acquirer mentioned in clonedLockInfo.
+     * There can occur a race condition where the original file is deleted before we can use it to acquire lock for the new acquirer. Until we have a
+     * fix on LockManager side, Implementors must ensure thread safety for this operation.
+     * @param originalLockInfo lock info instance for original lock.
+     * @param clonedLockInfo lock info instance for which lock needs to be cloned.
+     * @throws IOException throws IOException if originalResource itself do not have any lock.
+     */
+    void cloneLock(LockInfo originalLockInfo, LockInfo clonedLockInfo) throws IOException;
+
     /*
     Deletes all lock related files and directories
      */
diff --git a/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreMetadataLockManager.java b/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreMetadataLockManager.java
index 7df20cae10664..fd7906729e314 100644
--- a/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreMetadataLockManager.java
+++ b/server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreMetadataLockManager.java
@@ -15,8 +15,9 @@
 import org.opensearch.index.store.RemoteBufferedOutputDirectory;
 
 import java.io.IOException;
+import java.nio.file.NoSuchFileException;
 import java.util.Collection;
-import java.util.List;
+import java.util.Objects;
 
 /**
  * A Class that implements Remote Store Lock Manager by creating lock files for the remote store files that needs to
@@ -48,6 +49,7 @@ public void acquire(LockInfo lockInfo) throws IOException {
 
     /**
      * Releases Locks acquired by a given acquirer which is passed in LockInfo Instance.
+     * If the lock file doesn't exist for the acquirer, release will be a no-op.
      * Right now this method is only used to release locks for a given acquirer,
      * This can be extended in future to handle other cases as well, like:
      * - release lock for given fileToLock and AcquirerId
@@ -59,15 +61,12 @@ public void acquire(LockInfo lockInfo) throws IOException {
     public void release(LockInfo lockInfo) throws IOException {
         assert lockInfo instanceof FileLockInfo : "lockInfo should be instance of FileLockInfo";
         String[] lockFiles = lockDirectory.listAll();
-
-        // ideally there should be only one lock per acquirer, but just to handle any stale locks,
-        // we try to release all the locks for the acquirer.
-        List<String> locksToRelease = ((FileLockInfo) lockInfo).getLocksForAcquirer(lockFiles);
-        if (locksToRelease.size() > 1) {
-            logger.warn(locksToRelease.size() + " locks found for acquirer " + ((FileLockInfo) lockInfo).getAcquirerId());
-        }
-        for (String lock : locksToRelease) {
-            lockDirectory.deleteFile(lock);
+        try {
+            String lockToRelease = ((FileLockInfo) lockInfo).getLockForAcquirer(lockFiles);
+            lockDirectory.deleteFile(lockToRelease);
+        } catch (NoSuchFileException e) {
+            // Ignoring if the file to be deleted is not present.
+            logger.info("No lock file found for acquirerId: {}", ((FileLockInfo) lockInfo).getAcquirerId());
         }
     }
 
@@ -84,6 +83,27 @@ public Boolean isAcquired(LockInfo lockInfo) throws IOException {
         return !lockFiles.isEmpty();
     }
 
+    /**
+     * Acquires lock on the file mentioned in originalLockInfo for acquirer mentioned in clonedLockInfo.
+     * Snapshot layer enforces thread safety by having checks in place to ensure that the source snapshot is not being deleted before proceeding
+     * with the clone operation. Hence, the original lock file would always be present while acquiring the lock for cloned snapshot.
+     * @param originalLockInfo lock info instance for original lock.
+     * @param clonedLockInfo lock info instance for which lock needs to be cloned.
+     * @throws IOException throws IOException if originalResource itself do not have any lock.
+     */
+    @Override
+    public void cloneLock(LockInfo originalLockInfo, LockInfo clonedLockInfo) throws IOException {
+        assert originalLockInfo instanceof FileLockInfo : "originalLockInfo should be instance of FileLockInfo";
+        assert clonedLockInfo instanceof FileLockInfo : "clonedLockInfo should be instance of FileLockInfo";
+        String originalResourceId = Objects.requireNonNull(((FileLockInfo) originalLockInfo).getAcquirerId());
+        String clonedResourceId = Objects.requireNonNull(((FileLockInfo) clonedLockInfo).getAcquirerId());
+        assert originalResourceId != null && clonedResourceId != null : "provided resourceIds should not be null";
+        String[] lockFiles = lockDirectory.listAll();
+        String lockNameForAcquirer = ((FileLockInfo) originalLockInfo).getLockForAcquirer(lockFiles);
+        String fileToLockName = FileLockInfo.LockFileUtils.getFileToLockNameFromLock(lockNameForAcquirer);
+        acquire(FileLockInfo.getLockInfoBuilder().withFileToLock(fileToLockName).withAcquirerId(clonedResourceId).build());
+    }
+
     public void delete() throws IOException {
         lockDirectory.delete();
     }
diff --git a/server/src/main/java/org/opensearch/index/translog/InternalTranslogManager.java b/server/src/main/java/org/opensearch/index/translog/InternalTranslogManager.java
index 7eaab67ddb5a5..9b3240823f368 100644
--- a/server/src/main/java/org/opensearch/index/translog/InternalTranslogManager.java
+++ b/server/src/main/java/org/opensearch/index/translog/InternalTranslogManager.java
@@ -300,6 +300,11 @@ public void onDelete() {
         translog.onDelete();
     }
 
+    @Override
+    public Translog.TranslogGeneration getTranslogGeneration() {
+        return translog.getGeneration();
+    }
+
     /**
      * Reads operations from the translog
      * @param location location of translog
diff --git a/server/src/main/java/org/opensearch/index/translog/NoOpTranslogManager.java b/server/src/main/java/org/opensearch/index/translog/NoOpTranslogManager.java
index 58ee8c0fd39e7..dd5593b6d79cd 100644
--- a/server/src/main/java/org/opensearch/index/translog/NoOpTranslogManager.java
+++ b/server/src/main/java/org/opensearch/index/translog/NoOpTranslogManager.java
@@ -122,4 +122,9 @@ public Translog.Snapshot newChangesSnapshot(long fromSeqNo, long toSeqNo, boolea
     }
 
     public void onDelete() {}
+
+    @Override
+    public Translog.TranslogGeneration getTranslogGeneration() {
+        return null;
+    }
 }
diff --git a/server/src/main/java/org/opensearch/index/translog/TranslogManager.java b/server/src/main/java/org/opensearch/index/translog/TranslogManager.java
index 420d6cdc43bbf..78aaa1bc13a00 100644
--- a/server/src/main/java/org/opensearch/index/translog/TranslogManager.java
+++ b/server/src/main/java/org/opensearch/index/translog/TranslogManager.java
@@ -131,4 +131,6 @@ public interface TranslogManager {
     Clean up if any needed on deletion of index
      */
     void onDelete();
+
+    Translog.TranslogGeneration getTranslogGeneration();
 }
diff --git a/server/src/main/java/org/opensearch/node/Node.java b/server/src/main/java/org/opensearch/node/Node.java
index 3742c817118da..aecf5659de7fe 100644
--- a/server/src/main/java/org/opensearch/node/Node.java
+++ b/server/src/main/java/org/opensearch/node/Node.java
@@ -717,7 +717,8 @@ protected Node(
             clusterService.setRerouteService(rerouteService);
 
             final IndexStorePlugin.DirectoryFactory remoteDirectoryFactory = new RemoteSegmentStoreDirectoryFactory(
-                repositoriesServiceReference::get
+                repositoriesServiceReference::get,
+                threadPool
             );
 
             final IndicesService indicesService = new IndicesService(
@@ -1500,7 +1501,7 @@ public synchronized void close() throws IOException {
         toClose.add(injector.getInstance(NodeEnvironment.class));
         toClose.add(stopWatch::stop);
         if (FeatureFlags.isEnabled(TELEMETRY)) {
-            toClose.add(() -> injector.getInstance(TracerFactory.class));
+            toClose.add(injector.getInstance(TracerFactory.class));
         }
 
         if (logger.isTraceEnabled()) {
diff --git a/server/src/main/java/org/opensearch/plugins/SearchPipelinePlugin.java b/server/src/main/java/org/opensearch/plugins/SearchPipelinePlugin.java
index 3d76bab93a60c..d2ef2b65c5944 100644
--- a/server/src/main/java/org/opensearch/plugins/SearchPipelinePlugin.java
+++ b/server/src/main/java/org/opensearch/plugins/SearchPipelinePlugin.java
@@ -8,13 +8,24 @@
 
 package org.opensearch.plugins;
 
+import org.opensearch.client.Client;
+import org.opensearch.common.util.concurrent.ThreadContext;
+import org.opensearch.core.xcontent.NamedXContentRegistry;
+import org.opensearch.env.Environment;
+import org.opensearch.index.analysis.AnalysisRegistry;
+import org.opensearch.script.ScriptService;
 import org.opensearch.search.pipeline.Processor;
 import org.opensearch.search.pipeline.SearchPhaseResultsProcessor;
+import org.opensearch.search.pipeline.SearchPipelineService;
 import org.opensearch.search.pipeline.SearchRequestProcessor;
 import org.opensearch.search.pipeline.SearchResponseProcessor;
+import org.opensearch.threadpool.Scheduler;
 
 import java.util.Collections;
 import java.util.Map;
+import java.util.function.BiFunction;
+import java.util.function.Consumer;
+import java.util.function.LongSupplier;
 
 /**
  * An extension point for {@link Plugin} implementation to add custom search pipeline processors.
@@ -29,7 +40,7 @@ public interface SearchPipelinePlugin {
      * in pipeline configurations, and the value is a {@link org.opensearch.search.pipeline.Processor.Factory}
      * to create the processor from a given pipeline configuration.
      */
-    default Map<String, Processor.Factory<SearchRequestProcessor>> getRequestProcessors(Processor.Parameters parameters) {
+    default Map<String, Processor.Factory<SearchRequestProcessor>> getRequestProcessors(Parameters parameters) {
         return Collections.emptyMap();
     }
 
@@ -40,7 +51,7 @@ default Map<String, Processor.Factory<SearchRequestProcessor>> getRequestProcess
      * in pipeline configurations, and the value is a {@link org.opensearch.search.pipeline.Processor.Factory}
      * to create the processor from a given pipeline configuration.
      */
-    default Map<String, Processor.Factory<SearchResponseProcessor>> getResponseProcessors(Processor.Parameters parameters) {
+    default Map<String, Processor.Factory<SearchResponseProcessor>> getResponseProcessors(Parameters parameters) {
         return Collections.emptyMap();
     }
 
@@ -51,7 +62,78 @@ default Map<String, Processor.Factory<SearchResponseProcessor>> getResponseProce
      * in pipeline configurations, and the value is a {@link org.opensearch.search.pipeline.Processor.Factory}
      * to create the processor from a given pipeline configuration.
      */
-    default Map<String, Processor.Factory<SearchPhaseResultsProcessor>> getSearchPhaseResultsProcessors(Processor.Parameters parameters) {
+    default Map<String, Processor.Factory<SearchPhaseResultsProcessor>> getSearchPhaseResultsProcessors(Parameters parameters) {
         return Collections.emptyMap();
     }
+
+    /**
+     * Infrastructure class that holds services that can be used by processor factories to create processor instances
+     * and that gets passed around to all {@link SearchPipelinePlugin}s.
+     */
+    class Parameters {
+
+        /**
+         * Useful to provide access to the node's environment like config directory to processor factories.
+         */
+        public final Environment env;
+
+        /**
+         * Provides processors script support.
+         */
+        public final ScriptService scriptService;
+
+        /**
+         * Provide analyzer support
+         */
+        public final AnalysisRegistry analysisRegistry;
+
+        /**
+         * Allows processors to read headers set by {@link org.opensearch.action.support.ActionFilter}
+         * instances that have run while handling the current search.
+         */
+        public final ThreadContext threadContext;
+
+        public final LongSupplier relativeTimeSupplier;
+
+        public final SearchPipelineService searchPipelineService;
+
+        public final Consumer<Runnable> genericExecutor;
+
+        public final NamedXContentRegistry namedXContentRegistry;
+
+        /**
+         * Provides scheduler support
+         */
+        public final BiFunction<Long, Runnable, Scheduler.ScheduledCancellable> scheduler;
+
+        /**
+         * Provides access to the node's cluster client
+         */
+        public final Client client;
+
+        public Parameters(
+            Environment env,
+            ScriptService scriptService,
+            AnalysisRegistry analysisRegistry,
+            ThreadContext threadContext,
+            LongSupplier relativeTimeSupplier,
+            BiFunction<Long, Runnable, Scheduler.ScheduledCancellable> scheduler,
+            SearchPipelineService searchPipelineService,
+            Client client,
+            Consumer<Runnable> genericExecutor,
+            NamedXContentRegistry namedXContentRegistry
+        ) {
+            this.env = env;
+            this.scriptService = scriptService;
+            this.threadContext = threadContext;
+            this.analysisRegistry = analysisRegistry;
+            this.relativeTimeSupplier = relativeTimeSupplier;
+            this.scheduler = scheduler;
+            this.searchPipelineService = searchPipelineService;
+            this.client = client;
+            this.genericExecutor = genericExecutor;
+            this.namedXContentRegistry = namedXContentRegistry;
+        }
+
+    }
 }
diff --git a/server/src/main/java/org/opensearch/repositories/FilterRepository.java b/server/src/main/java/org/opensearch/repositories/FilterRepository.java
index b108e2da1ab04..764f36df6d337 100644
--- a/server/src/main/java/org/opensearch/repositories/FilterRepository.java
+++ b/server/src/main/java/org/opensearch/repositories/FilterRepository.java
@@ -47,6 +47,7 @@
 import org.opensearch.index.snapshots.IndexShardSnapshotStatus;
 import org.opensearch.index.snapshots.blobstore.RemoteStoreShardShallowCopySnapshot;
 import org.opensearch.index.store.Store;
+import org.opensearch.index.store.lockmanager.RemoteStoreLockManagerFactory;
 import org.opensearch.indices.recovery.RecoveryState;
 import org.opensearch.snapshots.SnapshotId;
 import org.opensearch.snapshots.SnapshotInfo;
@@ -248,6 +249,18 @@ public void executeConsistentStateUpdate(
         in.executeConsistentStateUpdate(createUpdateTask, source, onFailure);
     }
 
+    @Override
+    public void cloneRemoteStoreIndexShardSnapshot(
+        SnapshotId source,
+        SnapshotId target,
+        RepositoryShardId shardId,
+        String shardGeneration,
+        RemoteStoreLockManagerFactory remoteStoreLockManagerFactory,
+        ActionListener<String> listener
+    ) {
+        in.cloneRemoteStoreIndexShardSnapshot(source, target, shardId, shardGeneration, remoteStoreLockManagerFactory, listener);
+    }
+
     @Override
     public void cloneShardSnapshot(
         SnapshotId source,
diff --git a/server/src/main/java/org/opensearch/repositories/Repository.java b/server/src/main/java/org/opensearch/repositories/Repository.java
index c08369b79452d..793b3d317e1bd 100644
--- a/server/src/main/java/org/opensearch/repositories/Repository.java
+++ b/server/src/main/java/org/opensearch/repositories/Repository.java
@@ -48,6 +48,7 @@
 import org.opensearch.index.snapshots.IndexShardSnapshotStatus;
 import org.opensearch.index.snapshots.blobstore.RemoteStoreShardShallowCopySnapshot;
 import org.opensearch.index.store.Store;
+import org.opensearch.index.store.lockmanager.RemoteStoreLockManagerFactory;
 import org.opensearch.indices.recovery.RecoveryState;
 import org.opensearch.snapshots.SnapshotId;
 import org.opensearch.snapshots.SnapshotInfo;
@@ -375,6 +376,27 @@ void cloneShardSnapshot(
         ActionListener<String> listener
     );
 
+    /**
+     * Clones a remote store index shard snapshot.
+     *
+     * @param source                        source snapshot
+     * @param target                        target snapshot
+     * @param shardId                       shard id
+     * @param shardGeneration               shard generation in repo
+     * @param remoteStoreLockManagerFactory remoteStoreLockManagerFactory for cloning metadata lock file
+     * @param listener                      listener to complete with new shard generation once clone has completed
+     */
+    default void cloneRemoteStoreIndexShardSnapshot(
+        SnapshotId source,
+        SnapshotId target,
+        RepositoryShardId shardId,
+        @Nullable String shardGeneration,
+        RemoteStoreLockManagerFactory remoteStoreLockManagerFactory,
+        ActionListener<String> listener
+    ) {
+        throw new UnsupportedOperationException();
+    }
+
     /**
      * Hook that allows a repository to filter the user supplied snapshot metadata in {@link SnapshotsInProgress.Entry#userMetadata()}
      * during snapshot initialization.
diff --git a/server/src/main/java/org/opensearch/repositories/blobstore/BlobStoreRepository.java b/server/src/main/java/org/opensearch/repositories/blobstore/BlobStoreRepository.java
index f04bf83c2f1d1..be5fbf2ab6a51 100644
--- a/server/src/main/java/org/opensearch/repositories/blobstore/BlobStoreRepository.java
+++ b/server/src/main/java/org/opensearch/repositories/blobstore/BlobStoreRepository.java
@@ -114,6 +114,9 @@
 import org.opensearch.index.snapshots.blobstore.SnapshotFiles;
 import org.opensearch.index.store.Store;
 import org.opensearch.index.store.StoreFileMetadata;
+import org.opensearch.index.store.lockmanager.FileLockInfo;
+import org.opensearch.index.store.lockmanager.RemoteStoreLockManagerFactory;
+import org.opensearch.index.store.lockmanager.RemoteStoreMetadataLockManager;
 import org.opensearch.indices.recovery.RecoverySettings;
 import org.opensearch.indices.recovery.RecoveryState;
 import org.opensearch.repositories.IndexId;
@@ -506,8 +509,8 @@ public void cloneShardSnapshot(
         executor.execute(ActionRunnable.supply(listener, () -> {
             final long startTime = threadPool.absoluteTimeInMillis();
             final BlobContainer shardContainer = shardContainer(index, shardNum);
-            final BlobStoreIndexShardSnapshots existingSnapshots;
             final String newGen;
+            final BlobStoreIndexShardSnapshots existingSnapshots;
             final String existingShardGen;
             if (shardGeneration == null) {
                 Tuple<BlobStoreIndexShardSnapshots, Long> tuple = buildBlobStoreIndexShardSnapshots(
@@ -560,6 +563,9 @@ public void cloneShardSnapshot(
                         + "]. A snapshot by that name already exists for this shard."
                 );
             }
+            // We don't need to check if there exists a shallow snapshot with the same name as we have the check before starting the clone
+            // operation ensuring that the snapshot name is available by checking the repository data. Also, the new clone snapshot would
+            // have a different UUID and hence a new unique snap-N file will be created.
             final BlobStoreIndexShardSnapshot sourceMeta = loadShardSnapshot(shardContainer, source);
             logger.trace("[{}] [{}] writing shard snapshot file for clone", shardId, target);
             INDEX_SHARD_SNAPSHOT_FORMAT.write(
@@ -578,6 +584,50 @@ public void cloneShardSnapshot(
         }));
     }
 
+    @Override
+    public void cloneRemoteStoreIndexShardSnapshot(
+        SnapshotId source,
+        SnapshotId target,
+        RepositoryShardId shardId,
+        @Nullable String shardGeneration,
+        RemoteStoreLockManagerFactory remoteStoreLockManagerFactory,
+        ActionListener<String> listener
+    ) {
+        if (isReadOnly()) {
+            listener.onFailure(new RepositoryException(metadata.name(), "cannot clone shard snapshot on a readonly repository"));
+            return;
+        }
+        final IndexId index = shardId.index();
+        final int shardNum = shardId.shardId();
+        final Executor executor = threadPool.executor(ThreadPool.Names.SNAPSHOT);
+        executor.execute(ActionRunnable.supply(listener, () -> {
+            final long startTime = threadPool.relativeTimeInMillis();
+            final BlobContainer shardContainer = shardContainer(index, shardNum);
+            // We don't need to check if there exists a shallow/full copy snapshot with the same name as we have the check before starting
+            // the clone operation ensuring that the snapshot name is available by checking the repository data. Also, the new clone shallow
+            // snapshot would have a different UUID and hence a new unique shallow-snap-N file will be created.
+            RemoteStoreShardShallowCopySnapshot remStoreBasedShardMetadata = loadShallowCopyShardSnapshot(shardContainer, source);
+            String indexUUID = remStoreBasedShardMetadata.getIndexUUID();
+            String remoteStoreRepository = remStoreBasedShardMetadata.getRemoteStoreRepository();
+            RemoteStoreMetadataLockManager remoteStoreMetadataLockManger = remoteStoreLockManagerFactory.newLockManager(
+                remoteStoreRepository,
+                indexUUID,
+                String.valueOf(shardId.shardId())
+            );
+            remoteStoreMetadataLockManger.cloneLock(
+                FileLockInfo.getLockInfoBuilder().withAcquirerId(source.getUUID()).build(),
+                FileLockInfo.getLockInfoBuilder().withAcquirerId(target.getUUID()).build()
+            );
+            REMOTE_STORE_SHARD_SHALLOW_COPY_SNAPSHOT_FORMAT.write(
+                remStoreBasedShardMetadata.asClone(target.getName(), startTime, threadPool.absoluteTimeInMillis() - startTime),
+                shardContainer,
+                target.getUUID(),
+                compressor
+            );
+            return shardGeneration;
+        }));
+    }
+
     // Inspects all cluster state elements that contain a hint about what the current repository generation is and updates
     // #latestKnownRepoGen if a newer than currently known generation is found
     @Override
diff --git a/server/src/main/java/org/opensearch/rest/NamedRoute.java b/server/src/main/java/org/opensearch/rest/NamedRoute.java
index f5eaafcd04056..109f688a4924e 100644
--- a/server/src/main/java/org/opensearch/rest/NamedRoute.java
+++ b/server/src/main/java/org/opensearch/rest/NamedRoute.java
@@ -9,6 +9,13 @@
 package org.opensearch.rest;
 
 import org.opensearch.OpenSearchException;
+import org.opensearch.transport.TransportService;
+
+import java.util.HashSet;
+import java.util.Set;
+import java.util.function.Function;
+
+import static java.util.Objects.requireNonNull;
 
 /**
  * A named Route
@@ -16,21 +23,123 @@
  * @opensearch.internal
  */
 public class NamedRoute extends RestHandler.Route {
+
     private static final String VALID_ACTION_NAME_PATTERN = "^[a-zA-Z0-9:/*_]*$";
     static final int MAX_LENGTH_OF_ACTION_NAME = 250;
 
-    private final String name;
+    private final String uniqueName;
+    private final Set<String> actionNames;
 
-    public boolean isValidRouteName(String routeName) {
-        if (routeName == null || routeName.isBlank() || routeName.length() > MAX_LENGTH_OF_ACTION_NAME) {
-            return false;
+    private Function<RestRequest, RestResponse> handler;
+
+    /**
+     * Builder class for constructing instances of {@link NamedRoute}.
+     */
+    public static class Builder {
+        private RestRequest.Method method;
+        private String path;
+        private String uniqueName;
+        private final Set<String> legacyActionNames = new HashSet<>();
+        private Function<RestRequest, RestResponse> handler;
+
+        /**
+         * Sets the REST method for the route.
+         *
+         * @param method the REST method for the route
+         * @return the builder instance
+         */
+        public Builder method(RestRequest.Method method) {
+            requireNonNull(method, "REST method must not be null.");
+            this.method = method;
+            return this;
+        }
+
+        /**
+         * Sets the URL path for the route.
+         *
+         * @param path the URL path for the route
+         * @return the builder instance
+         */
+        public Builder path(String path) {
+            requireNonNull(path, "REST path must not be null.");
+            this.path = path;
+            return this;
+        }
+
+        /**
+         * Sets the name for the route.
+         *
+         * @param name the name for the route
+         * @return the builder instance
+         */
+        public Builder uniqueName(String name) {
+            requireNonNull(name, "REST route name must not be null.");
+            this.uniqueName = name;
+            return this;
+        }
+
+        /**
+         * Sets the legacy action names for the route.
+         *
+         * @param legacyActionNames the legacy action names for the route
+         * @return the builder instance
+         */
+        public Builder legacyActionNames(Set<String> legacyActionNames) {
+            this.legacyActionNames.addAll(validateLegacyActionNames(legacyActionNames));
+            return this;
+        }
+
+        /**
+         * Sets the handler for this route
+         *
+         * @param handler the handler for this route
+         * @return the builder instance
+         */
+        public Builder handler(Function<RestRequest, RestResponse> handler) {
+            requireNonNull(handler, "Route handler must not be null.");
+            this.handler = handler;
+            return this;
+        }
+
+        /**
+         * Builds a new instance of {@link NamedRoute} based on the provided parameters.
+         *
+         * @return a new instance of {@link NamedRoute}
+         * @throws OpenSearchException if the route name is invalid
+         */
+        public NamedRoute build() {
+            checkIfFieldsAreSet();
+            return new NamedRoute(this);
+        }
+
+        /**
+         * Checks if all builder fields are set before creating a new NamedRoute object
+         */
+        private void checkIfFieldsAreSet() {
+            if (method == null || path == null || uniqueName == null) {
+                throw new IllegalStateException("REST method, path and uniqueName are required.");
+            }
+        }
+
+        private Set<String> validateLegacyActionNames(Set<String> legacyActionNames) {
+            if (legacyActionNames == null) {
+                return new HashSet<>();
+            }
+            for (String actionName : legacyActionNames) {
+                if (!TransportService.isValidActionName(actionName)) {
+                    throw new OpenSearchException(
+                        "Invalid action name [" + actionName + "]. It must start with one of: " + TransportService.VALID_ACTION_PREFIXES
+                    );
+                }
+            }
+            return legacyActionNames;
         }
-        return routeName.matches(VALID_ACTION_NAME_PATTERN);
+
     }
 
-    public NamedRoute(RestRequest.Method method, String path, String name) {
-        super(method, path);
-        if (!isValidRouteName(name)) {
+    private NamedRoute(Builder builder) {
+        super(builder.method, builder.path);
+        if (!isValidRouteName(builder.uniqueName)) {
             throw new OpenSearchException(
                 "Invalid route name specified. The route name may include the following characters"
                     + " 'a-z', 'A-Z', '0-9', ':', '/', '*', '_' and be less than "
@@ -38,18 +147,43 @@ public NamedRoute(RestRequest.Method method, String path, String name) {
                     + " characters"
             );
         }
-        this.name = name;
+        this.uniqueName = builder.uniqueName;
+        this.actionNames = Set.copyOf(builder.legacyActionNames);
+        this.handler = builder.handler;
+    }
+
+    public boolean isValidRouteName(String routeName) {
+        return routeName != null
+            && !routeName.isBlank()
+            && routeName.length() <= MAX_LENGTH_OF_ACTION_NAME
+            && routeName.matches(VALID_ACTION_NAME_PATTERN);
     }
 
     /**
      * The name of the Route. Must be unique across Route.
      */
     public String name() {
-        return this.name;
+        return this.uniqueName;
+    }
+
+    /**
+     * The legacy transport Action name to match against this route to support authorization in REST layer.
+     * MUST be unique across all Routes
+     */
+    public Set<String> actionNames() {
+        return this.actionNames;
+    }
+
+    /**
+     * The handler associated with this route
+     * @return the handler associated with this route
+     */
+    public Function<RestRequest, RestResponse> handler() {
+        return handler;
     }
 
     @Override
     public String toString() {
-        return "NamedRoute [method=" + method + ", path=" + path + ", name=" + name + "]";
+        return "NamedRoute [method=" + method + ", path=" + path + ", name=" + uniqueName + ", actionNames=" + actionNames + "]";
     }
 }
diff --git a/server/src/main/java/org/opensearch/search/SearchService.java b/server/src/main/java/org/opensearch/search/SearchService.java
index 7d67c6c3b45f4..9daad9112e473 100644
--- a/server/src/main/java/org/opensearch/search/SearchService.java
+++ b/server/src/main/java/org/opensearch/search/SearchService.java
@@ -1550,7 +1550,9 @@ private CanMatchResponse canMatch(ShardSearchRequest request, boolean checkRefre
     }
 
     public static boolean canMatchSearchAfter(FieldDoc searchAfter, MinAndMax<?> minMax, FieldSortBuilder primarySortField) {
-        if (searchAfter != null && minMax != null && primarySortField != null) {
+        // Check for sort.missing == null, since in case of missing values sort queries, if segment/shard's min/max
+        // is out of search_after range, it still should be printed and hence we should not skip segment/shard.
+        if (searchAfter != null && minMax != null && primarySortField != null && primarySortField.missing() == null) {
             final Object searchAfterPrimary = searchAfter.fields[0];
             if (primarySortField.order() == SortOrder.DESC) {
                 if (minMax.compareMin(searchAfterPrimary) > 0) {
diff --git a/server/src/main/java/org/opensearch/search/pipeline/PipelineWithMetrics.java b/server/src/main/java/org/opensearch/search/pipeline/PipelineWithMetrics.java
index 612e979e56070..060894a37e5ed 100644
--- a/server/src/main/java/org/opensearch/search/pipeline/PipelineWithMetrics.java
+++ b/server/src/main/java/org/opensearch/search/pipeline/PipelineWithMetrics.java
@@ -77,19 +77,28 @@ static PipelineWithMetrics create(
         Map<String, Processor.Factory<SearchPhaseResultsProcessor>> phaseResultsProcessorFactories,
         NamedWriteableRegistry namedWriteableRegistry,
         OperationMetrics totalRequestProcessingMetrics,
-        OperationMetrics totalResponseProcessingMetrics
+        OperationMetrics totalResponseProcessingMetrics,
+        Processor.PipelineContext pipelineContext
     ) throws Exception {
         String description = ConfigurationUtils.readOptionalStringProperty(null, null, config, DESCRIPTION_KEY);
         Integer version = ConfigurationUtils.readIntProperty(null, null, config, VERSION_KEY, null);
         List<Map<String, Object>> requestProcessorConfigs = ConfigurationUtils.readOptionalList(null, null, config, REQUEST_PROCESSORS_KEY);
-        List<SearchRequestProcessor> requestProcessors = readProcessors(requestProcessorFactories, requestProcessorConfigs);
+        List<SearchRequestProcessor> requestProcessors = readProcessors(
+            requestProcessorFactories,
+            requestProcessorConfigs,
+            pipelineContext
+        );
         List<Map<String, Object>> responseProcessorConfigs = ConfigurationUtils.readOptionalList(
             null,
             null,
             config,
             RESPONSE_PROCESSORS_KEY
         );
-        List<SearchResponseProcessor> responseProcessors = readProcessors(responseProcessorFactories, responseProcessorConfigs);
+        List<SearchResponseProcessor> responseProcessors = readProcessors(
+            responseProcessorFactories,
+            responseProcessorConfigs,
+            pipelineContext
+        );
         List<Map<String, Object>> phaseResultsProcessorConfigs = ConfigurationUtils.readOptionalList(
             null,
             null,
@@ -98,7 +107,8 @@ static PipelineWithMetrics create(
         );
         List<SearchPhaseResultsProcessor> phaseResultsProcessors = readProcessors(
             phaseResultsProcessorFactories,
-            phaseResultsProcessorConfigs
+            phaseResultsProcessorConfigs,
+            pipelineContext
         );
         if (config.isEmpty() == false) {
             throw new OpenSearchParseException(
@@ -125,7 +135,8 @@ static PipelineWithMetrics create(
 
     private static <T extends Processor> List<T> readProcessors(
         Map<String, Processor.Factory<T>> processorFactories,
-        List<Map<String, Object>> requestProcessorConfigs
+        List<Map<String, Object>> requestProcessorConfigs,
+        Processor.PipelineContext pipelineContext
     ) throws Exception {
         List<T> processors = new ArrayList<>();
         if (requestProcessorConfigs == null) {
@@ -140,7 +151,19 @@ private static <T extends Processor> List<T> readProcessors(
                 Map<String, Object> config = (Map<String, Object>) entry.getValue();
                 String tag = ConfigurationUtils.readOptionalStringProperty(null, null, config, TAG_KEY);
                 String description = ConfigurationUtils.readOptionalStringProperty(null, tag, config, DESCRIPTION_KEY);
-                processors.add(processorFactories.get(type).create(processorFactories, tag, description, config));
+                processors.add(processorFactories.get(type).create(processorFactories, tag, description, config, pipelineContext));
+                if (config.isEmpty() == false) {
+                    String processorName = type;
+                    if (tag != null) {
+                        processorName = processorName + ":" + tag;
+                    }
+                    throw new OpenSearchParseException(
+                        "processor ["
+                            + processorName
+                            + "] doesn't support one or more provided configuration parameters: "
+                            + Arrays.toString(config.keySet().toArray())
+                    );
+                }
             }
         }
         return Collections.unmodifiableList(processors);
diff --git a/server/src/main/java/org/opensearch/search/pipeline/Processor.java b/server/src/main/java/org/opensearch/search/pipeline/Processor.java
index ee28db1cc334d..cc96132479c74 100644
--- a/server/src/main/java/org/opensearch/search/pipeline/Processor.java
+++ b/server/src/main/java/org/opensearch/search/pipeline/Processor.java
@@ -8,19 +8,7 @@
 
 package org.opensearch.search.pipeline;
 
-import org.opensearch.client.Client;
-import org.opensearch.common.util.concurrent.ThreadContext;
-import org.opensearch.core.xcontent.NamedXContentRegistry;
-import org.opensearch.env.Environment;
-import org.opensearch.index.analysis.AnalysisRegistry;
-import org.opensearch.plugins.SearchPipelinePlugin;
-import org.opensearch.script.ScriptService;
-import org.opensearch.threadpool.Scheduler;
-
 import java.util.Map;
-import java.util.function.BiFunction;
-import java.util.function.Consumer;
-import java.util.function.LongSupplier;
 
 /**
  * A processor implementation may modify the request or response from a search call.
@@ -33,6 +21,12 @@
  * @opensearch.internal
  */
 public interface Processor {
+    /**
+     * Processor configuration key to let the factory know the context for pipeline creation.
+     * <p>
+     * See {@link PipelineSource}.
+     */
+    String PIPELINE_SOURCE = "pipeline_source";
 
     /**
      * Gets the type of processor
@@ -61,81 +55,45 @@ interface Factory<T extends Processor> {
          * @param tag                The tag for the processor
          * @param description        A short description of what this processor does
          * @param config             The configuration for the processor
-         *
          *                           <b>Note:</b> Implementations are responsible for removing the used configuration
          *                           keys, so that after creation the config map should be empty.
+         * @param pipelineContext    Contextual information about the enclosing pipeline.
          */
-        T create(Map<String, Factory<T>> processorFactories, String tag, String description, Map<String, Object> config) throws Exception;
+        T create(
+            Map<String, Factory<T>> processorFactories,
+            String tag,
+            String description,
+            Map<String, Object> config,
+            PipelineContext pipelineContext
+        ) throws Exception;
     }
 
     /**
-     * Infrastructure class that holds services that can be used by processor factories to create processor instances
-     * and that gets passed around to all {@link SearchPipelinePlugin}s.
+     * Contextual information about the enclosing pipeline. A processor factory may change processor initialization behavior or
+     * pass this information to the created processor instance.
      */
-    class Parameters {
+    class PipelineContext {
+        private final PipelineSource pipelineSource;
 
-        /**
-         * Useful to provide access to the node's environment like config directory to processor factories.
-         */
-        public final Environment env;
-
-        /**
-         * Provides processors script support.
-         */
-        public final ScriptService scriptService;
-
-        /**
-         * Provide analyzer support
-         */
-        public final AnalysisRegistry analysisRegistry;
-
-        /**
-         * Allows processors to read headers set by {@link org.opensearch.action.support.ActionFilter}
-         * instances that have run while handling the current search.
-         */
-        public final ThreadContext threadContext;
-
-        public final LongSupplier relativeTimeSupplier;
-
-        public final SearchPipelineService searchPipelineService;
-
-        public final Consumer<Runnable> genericExecutor;
-
-        public final NamedXContentRegistry namedXContentRegistry;
-
-        /**
-         * Provides scheduler support
-         */
-        public final BiFunction<Long, Runnable, Scheduler.ScheduledCancellable> scheduler;
-
-        /**
-         * Provides access to the node's cluster client
-         */
-        public final Client client;
+        public PipelineContext(PipelineSource pipelineSource) {
+            this.pipelineSource = pipelineSource;
+        }
 
-        public Parameters(
-            Environment env,
-            ScriptService scriptService,
-            AnalysisRegistry analysisRegistry,
-            ThreadContext threadContext,
-            LongSupplier relativeTimeSupplier,
-            BiFunction<Long, Runnable, Scheduler.ScheduledCancellable> scheduler,
-            SearchPipelineService searchPipelineService,
-            Client client,
-            Consumer<Runnable> genericExecutor,
-            NamedXContentRegistry namedXContentRegistry
-        ) {
-            this.env = env;
-            this.scriptService = scriptService;
-            this.threadContext = threadContext;
-            this.analysisRegistry = analysisRegistry;
-            this.relativeTimeSupplier = relativeTimeSupplier;
-            this.scheduler = scheduler;
-            this.searchPipelineService = searchPipelineService;
-            this.client = client;
-            this.genericExecutor = genericExecutor;
-            this.namedXContentRegistry = namedXContentRegistry;
+        public PipelineSource getPipelineSource() {
+            return pipelineSource;
         }
+    }
 
+    /**
+     * A processor factory may change the processor initialization behavior based on the creation context (e.g. avoiding
+     * creating expensive resources during validation or in a request-scoped pipeline.)
+     */
+    enum PipelineSource {
+        // A named pipeline is being created or updated
+        UPDATE_PIPELINE,
+        // Pipeline is defined within a search request
+        SEARCH_REQUEST,
+        // A named pipeline is being validated before being written to cluster state
+        VALIDATE_PIPELINE
     }
 }
diff --git a/server/src/main/java/org/opensearch/search/pipeline/SearchPipelineService.java b/server/src/main/java/org/opensearch/search/pipeline/SearchPipelineService.java
index 70dc8546a077f..83a7a0564467e 100644
--- a/server/src/main/java/org/opensearch/search/pipeline/SearchPipelineService.java
+++ b/server/src/main/java/org/opensearch/search/pipeline/SearchPipelineService.java
@@ -103,7 +103,7 @@ public SearchPipelineService(
         this.scriptService = scriptService;
         this.threadPool = threadPool;
         this.namedWriteableRegistry = namedWriteableRegistry;
-        Processor.Parameters parameters = new Processor.Parameters(
+        SearchPipelinePlugin.Parameters parameters = new SearchPipelinePlugin.Parameters(
             env,
             scriptService,
             analysisRegistry,
@@ -189,7 +189,8 @@ void innerUpdatePipelines(SearchPipelineMetadata newSearchPipelineMetadata) {
                     phaseInjectorProcessorFactories,
                     namedWriteableRegistry,
                     totalRequestProcessingMetrics,
-                    totalResponseProcessingMetrics
+                    totalResponseProcessingMetrics,
+                    new Processor.PipelineContext(Processor.PipelineSource.UPDATE_PIPELINE)
                 );
                 newPipelines.put(newConfiguration.getId(), new PipelineHolder(newConfiguration, newPipeline));
 
@@ -289,7 +290,8 @@ void validatePipeline(Map<DiscoveryNode, SearchPipelineInfo> searchPipelineInfos
             phaseInjectorProcessorFactories,
             namedWriteableRegistry,
             new OperationMetrics(), // Use ephemeral metrics for validation
-            new OperationMetrics()
+            new OperationMetrics(),
+            new Processor.PipelineContext(Processor.PipelineSource.VALIDATE_PIPELINE)
         );
         List<Exception> exceptions = new ArrayList<>();
         for (SearchRequestProcessor processor : pipeline.getSearchRequestProcessors()) {
@@ -388,7 +390,8 @@ public PipelinedRequest resolvePipeline(SearchRequest searchRequest) {
                     phaseInjectorProcessorFactories,
                     namedWriteableRegistry,
                     totalRequestProcessingMetrics,
-                    totalResponseProcessingMetrics
+                    totalResponseProcessingMetrics,
+                    new Processor.PipelineContext(Processor.PipelineSource.SEARCH_REQUEST)
                 );
             } catch (Exception e) {
                 throw new SearchPipelineProcessingException(e);
diff --git a/server/src/main/java/org/opensearch/snapshots/SnapshotInfo.java b/server/src/main/java/org/opensearch/snapshots/SnapshotInfo.java
index 1619f36738f7b..6bdbcfee29a9a 100644
--- a/server/src/main/java/org/opensearch/snapshots/SnapshotInfo.java
+++ b/server/src/main/java/org/opensearch/snapshots/SnapshotInfo.java
@@ -532,6 +532,7 @@ public Boolean includeGlobalState() {
         return includeGlobalState;
     }
 
+    @Nullable
     public Boolean isRemoteStoreIndexShallowCopyEnabled() {
         return remoteStoreIndexShallowCopy;
     }
diff --git a/server/src/main/java/org/opensearch/snapshots/SnapshotsService.java b/server/src/main/java/org/opensearch/snapshots/SnapshotsService.java
index b523c1ba12b05..0a455c376f62d 100644
--- a/server/src/main/java/org/opensearch/snapshots/SnapshotsService.java
+++ b/server/src/main/java/org/opensearch/snapshots/SnapshotsService.java
@@ -88,8 +88,10 @@
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.concurrent.AbstractRunnable;
 import org.opensearch.index.Index;
 import org.opensearch.index.shard.ShardId;
+import org.opensearch.index.store.lockmanager.RemoteStoreLockManagerFactory;
 import org.opensearch.repositories.IndexId;
 import org.opensearch.repositories.RepositoriesService;
 import org.opensearch.repositories.Repository;
@@ -151,6 +153,8 @@ public class SnapshotsService extends AbstractLifecycleComponent implements Clus
 
     private final RepositoriesService repositoriesService;
 
+    private final RemoteStoreLockManagerFactory remoteStoreLockManagerFactory;
+
     private final ThreadPool threadPool;
 
     private final Map<Snapshot, List<ActionListener<Tuple<RepositoryData, SnapshotInfo>>>> snapshotCompletionListeners =
@@ -206,6 +210,7 @@ public SnapshotsService(
         this.clusterService = clusterService;
         this.indexNameExpressionResolver = indexNameExpressionResolver;
         this.repositoriesService = repositoriesService;
+        this.remoteStoreLockManagerFactory = new RemoteStoreLockManagerFactory(() -> repositoriesService);
         this.threadPool = transportService.getThreadPool();
         this.transportService = transportService;
 
@@ -621,7 +626,11 @@ public ClusterState execute(ClusterState currentState) {
                                 }
                             }
                         }
-                        updatedEntry = cloneEntry.withClones(clonesBuilder);
+                        updatedEntry = cloneEntry.withClones(clonesBuilder)
+                            .withRemoteStoreIndexShallowCopy(
+                                Boolean.TRUE.equals(snapshotInfoListener.result().isRemoteStoreIndexShallowCopyEnabled())
+                            );
+                        ;
                         updatedEntries.set(i, updatedEntry);
                         changed = true;
                         break;
@@ -649,7 +658,8 @@ public void clusterStateProcessed(String source, ClusterState oldState, ClusterS
                             continue;
                         }
                         final RepositoryShardId repoShardId = indexClone.getKey();
-                        runReadyClone(target, sourceSnapshot, shardStatusBefore, repoShardId, repository);
+                        final boolean remoteStoreIndexShallowCopy = Boolean.TRUE.equals(updatedEntry.remoteStoreIndexShallowCopy());
+                        runReadyClone(target, sourceSnapshot, shardStatusBefore, repoShardId, repository, remoteStoreIndexShallowCopy);
                     }
                 } else {
                     // Extremely unlikely corner case of cluster-manager failing over between between starting the clone and
@@ -667,60 +677,112 @@ private void runReadyClone(
         SnapshotId sourceSnapshot,
         ShardSnapshotStatus shardStatusBefore,
         RepositoryShardId repoShardId,
-        Repository repository
+        Repository repository,
+        boolean remoteStoreIndexShallowCopy
     ) {
-        final SnapshotId targetSnapshot = target.getSnapshotId();
-        final String localNodeId = clusterService.localNode().getId();
-        if (currentlyCloning.add(repoShardId)) {
-            repository.cloneShardSnapshot(
-                sourceSnapshot,
-                targetSnapshot,
-                repoShardId,
-                shardStatusBefore.generation(),
-                ActionListener.wrap(
-                    generation -> innerUpdateSnapshotState(
-                        new ShardSnapshotUpdate(target, repoShardId, new ShardSnapshotStatus(localNodeId, ShardState.SUCCESS, generation)),
-                        ActionListener.runBefore(
-                            ActionListener.wrap(
-                                v -> logger.trace(
-                                    "Marked [{}] as successfully cloned from [{}] to [{}]",
+        final Executor executor = threadPool.executor(ThreadPool.Names.SNAPSHOT);
+        executor.execute(new AbstractRunnable() {
+            @Override
+            public void onFailure(Exception e) {
+                logger.warn(
+                    "Failed to get repository data while cloning shard [{}] from [{}] to [{}]",
+                    repoShardId,
+                    sourceSnapshot,
+                    target.getSnapshotId()
+                );
+                failCloneShardAndUpdateClusterState(target, sourceSnapshot, repoShardId);
+            }
+
+            @Override
+            protected void doRun() {
+                final String localNodeId = clusterService.localNode().getId();
+                repository.getRepositoryData(ActionListener.wrap(repositoryData -> {
+                    try {
+                        final IndexMetadata indexMetadata = repository.getSnapshotIndexMetaData(
+                            repositoryData,
+                            sourceSnapshot,
+                            repoShardId.index()
+                        );
+                        final boolean cloneRemoteStoreIndexShardSnapshot = remoteStoreIndexShallowCopy
+                            && indexMetadata.getSettings().getAsBoolean(IndexMetadata.SETTING_REMOTE_STORE_ENABLED, false);
+                        final SnapshotId targetSnapshot = target.getSnapshotId();
+                        final ActionListener<String> listener = ActionListener.wrap(
+                            generation -> innerUpdateSnapshotState(
+                                new ShardSnapshotUpdate(
+                                    target,
                                     repoShardId,
-                                    sourceSnapshot,
-                                    targetSnapshot
+                                    new ShardSnapshotStatus(localNodeId, ShardState.SUCCESS, generation)
                                 ),
-                                e -> {
-                                    logger.warn("Cluster state update after successful shard clone [{}] failed", repoShardId);
-                                    failAllListenersOnMasterFailOver(e);
-                                }
+                                ActionListener.runBefore(
+                                    ActionListener.wrap(
+                                        v -> logger.trace(
+                                            "Marked [{}] as successfully cloned from [{}] to [{}]",
+                                            repoShardId,
+                                            sourceSnapshot,
+                                            targetSnapshot
+                                        ),
+                                        e -> {
+                                            logger.warn("Cluster state update after successful shard clone [{}] failed", repoShardId);
+                                            failAllListenersOnMasterFailOver(e);
+                                        }
+                                    ),
+                                    () -> currentlyCloning.remove(repoShardId)
+                                )
                             ),
-                            () -> currentlyCloning.remove(repoShardId)
-                        )
-                    ),
-                    e -> innerUpdateSnapshotState(
-                        new ShardSnapshotUpdate(
-                            target,
-                            repoShardId,
-                            new ShardSnapshotStatus(localNodeId, ShardState.FAILED, "failed to clone shard snapshot", null)
-                        ),
-                        ActionListener.runBefore(
-                            ActionListener.wrap(
-                                v -> logger.trace(
-                                    "Marked [{}] as failed clone from [{}] to [{}]",
+                            e -> {
+                                logger.warn("Exception [{}] while trying to clone shard [{}]", e, repoShardId);
+                                failCloneShardAndUpdateClusterState(target, sourceSnapshot, repoShardId);
+                            }
+                        );
+                        if (currentlyCloning.add(repoShardId)) {
+                            if (cloneRemoteStoreIndexShardSnapshot) {
+                                repository.cloneRemoteStoreIndexShardSnapshot(
+                                    sourceSnapshot,
+                                    targetSnapshot,
                                     repoShardId,
+                                    shardStatusBefore.generation(),
+                                    remoteStoreLockManagerFactory,
+                                    listener
+                                );
+                            } else {
+                                repository.cloneShardSnapshot(
                                     sourceSnapshot,
-                                    targetSnapshot
-                                ),
-                                ex -> {
-                                    logger.warn("Cluster state update after failed shard clone [{}] failed", repoShardId);
-                                    failAllListenersOnMasterFailOver(ex);
-                                }
-                            ),
-                            () -> currentlyCloning.remove(repoShardId)
-                        )
-                    )
-                )
-            );
-        }
+                                    targetSnapshot,
+                                    repoShardId,
+                                    shardStatusBefore.generation(),
+                                    listener
+                                );
+                            }
+                        }
+                    } catch (IOException e) {
+                        logger.warn("Failed to get index-metadata from repository data for index [{}]", repoShardId.index().getName());
+                        failCloneShardAndUpdateClusterState(target, sourceSnapshot, repoShardId);
+                    }
+                }, this::onFailure));
+            }
+        });
+    }
+
+    private void failCloneShardAndUpdateClusterState(Snapshot target, SnapshotId sourceSnapshot, RepositoryShardId repoShardId) {
+        // Stale blobs/lock-files will be cleaned up during delete/cleanup operation.
+        final String localNodeId = clusterService.localNode().getId();
+        innerUpdateSnapshotState(
+            new ShardSnapshotUpdate(
+                target,
+                repoShardId,
+                new ShardSnapshotStatus(localNodeId, ShardState.FAILED, "failed to clone shard snapshot", null)
+            ),
+            ActionListener.runBefore(
+                ActionListener.wrap(
+                    v -> logger.trace("Marked [{}] as failed clone from [{}] to [{}]", repoShardId, sourceSnapshot, target.getSnapshotId()),
+                    ex -> {
+                        logger.warn("Cluster state update after failed shard clone [{}] failed", repoShardId);
+                        failAllListenersOnMasterFailOver(ex);
+                    }
+                ),
+                () -> currentlyCloning.remove(repoShardId)
+            )
+        );
     }
 
     private void ensureBelowConcurrencyLimit(
@@ -3077,12 +3139,14 @@ private void startExecutableClones(SnapshotsInProgress snapshotsInProgress, @Nul
                 // this is a clone, see if new work is ready
                 for (final Map.Entry<RepositoryShardId, ShardSnapshotStatus> clone : entry.clones().entrySet()) {
                     if (clone.getValue().state() == ShardState.INIT) {
+                        final boolean remoteStoreIndexShallowCopy = Boolean.TRUE.equals(entry.remoteStoreIndexShallowCopy());
                         runReadyClone(
                             entry.snapshot(),
                             entry.source(),
                             clone.getValue(),
                             clone.getKey(),
-                            repositoriesService.repository(entry.repository())
+                            repositoriesService.repository(entry.repository()),
+                            remoteStoreIndexShallowCopy
                         );
                     }
                 }
diff --git a/server/src/test/java/org/opensearch/action/DynamicActionRegistryTests.java b/server/src/test/java/org/opensearch/action/DynamicActionRegistryTests.java
index 963d47df3baff..17e424ee81e7e 100644
--- a/server/src/test/java/org/opensearch/action/DynamicActionRegistryTests.java
+++ b/server/src/test/java/org/opensearch/action/DynamicActionRegistryTests.java
@@ -26,6 +26,7 @@
 import java.io.IOException;
 import java.util.Collections;
 import java.util.Map;
+import java.util.Set;
 
 import static org.mockito.Mockito.mock;
 
@@ -80,8 +81,8 @@ public void testDynamicActionRegistry() {
     public void testDynamicActionRegistryWithNamedRoutes() {
         RestSendToExtensionAction action = mock(RestSendToExtensionAction.class);
         RestSendToExtensionAction action2 = mock(RestSendToExtensionAction.class);
-        NamedRoute r1 = new NamedRoute(RestRequest.Method.GET, "/foo", "foo");
-        NamedRoute r2 = new NamedRoute(RestRequest.Method.GET, "/bar", "bar");
+        NamedRoute r1 = new NamedRoute.Builder().method(RestRequest.Method.GET).path("/foo").uniqueName("foo").build();
+        NamedRoute r2 = new NamedRoute.Builder().method(RestRequest.Method.PUT).path("/bar").uniqueName("bar").build();
 
         DynamicActionRegistry registry = new DynamicActionRegistry();
         registry.registerDynamicRoute(r1, action);
@@ -89,22 +90,38 @@ public void testDynamicActionRegistryWithNamedRoutes() {
 
         assertTrue(registry.isActionRegistered("foo"));
         assertTrue(registry.isActionRegistered("bar"));
+
+        registry.unregisterDynamicRoute(r2);
+
+        assertTrue(registry.isActionRegistered("foo"));
+        assertFalse(registry.isActionRegistered("bar"));
     }
 
-    public void testDynamicActionRegistryRegisterAndUnregisterWithNamedRoutes() {
+    public void testDynamicActionRegistryWithNamedRoutesAndLegacyActionNames() {
         RestSendToExtensionAction action = mock(RestSendToExtensionAction.class);
         RestSendToExtensionAction action2 = mock(RestSendToExtensionAction.class);
-        NamedRoute r1 = new NamedRoute(RestRequest.Method.GET, "/foo", "foo");
-        NamedRoute r2 = new NamedRoute(RestRequest.Method.GET, "/bar", "bar");
+        NamedRoute r1 = new NamedRoute.Builder().method(RestRequest.Method.GET)
+            .path("/foo")
+            .uniqueName("foo")
+            .legacyActionNames(Set.of("cluster:admin/opensearch/abc/foo"))
+            .build();
+        NamedRoute r2 = new NamedRoute.Builder().method(RestRequest.Method.PUT)
+            .path("/bar")
+            .uniqueName("bar")
+            .legacyActionNames(Set.of("cluster:admin/opensearch/xyz/bar"))
+            .build();
 
         DynamicActionRegistry registry = new DynamicActionRegistry();
         registry.registerDynamicRoute(r1, action);
         registry.registerDynamicRoute(r2, action2);
 
+        assertTrue(registry.isActionRegistered("cluster:admin/opensearch/abc/foo"));
+        assertTrue(registry.isActionRegistered("cluster:admin/opensearch/xyz/bar"));
+
         registry.unregisterDynamicRoute(r2);
 
-        assertTrue(registry.isActionRegistered("foo"));
-        assertFalse(registry.isActionRegistered("bar"));
+        assertTrue(registry.isActionRegistered("cluster:admin/opensearch/abc/foo"));
+        assertFalse(registry.isActionRegistered("cluster:admin/opensearch/xyz/bar"));
     }
 
     private static final class TestAction extends ActionType<ActionResponse> {
diff --git a/server/src/test/java/org/opensearch/cluster/metadata/MetadataCreateIndexServiceTests.java b/server/src/test/java/org/opensearch/cluster/metadata/MetadataCreateIndexServiceTests.java
index 94a1ca9992cb6..c70fedbaf24bd 100644
--- a/server/src/test/java/org/opensearch/cluster/metadata/MetadataCreateIndexServiceTests.java
+++ b/server/src/test/java/org/opensearch/cluster/metadata/MetadataCreateIndexServiceTests.java
@@ -817,8 +817,7 @@ public void testAggregateSettingsAppliesSettingsFromTemplatesAndRequest() {
             Settings.EMPTY,
             IndexScopedSettings.DEFAULT_SCOPED_SETTINGS,
             randomShardLimitService(),
-            Collections.emptySet(),
-            false
+            Collections.emptySet()
         );
 
         assertThat(aggregatedIndexSettings.get("template_setting"), equalTo("value1"));
@@ -880,8 +879,7 @@ public void testRequestDataHavePriorityOverTemplateData() throws Exception {
             Settings.EMPTY,
             IndexScopedSettings.DEFAULT_SCOPED_SETTINGS,
             randomShardLimitService(),
-            Collections.emptySet(),
-            false
+            Collections.emptySet()
         );
 
         assertThat(resolvedAliases.get(0).getSearchRouting(), equalTo("fromRequest"));
@@ -903,8 +901,7 @@ public void testDefaultSettings() {
             Settings.EMPTY,
             IndexScopedSettings.DEFAULT_SCOPED_SETTINGS,
             randomShardLimitService(),
-            Collections.emptySet(),
-            false
+            Collections.emptySet()
         );
 
         assertThat(aggregatedIndexSettings.get(SETTING_NUMBER_OF_SHARDS), equalTo("1"));
@@ -919,8 +916,7 @@ public void testSettingsFromClusterState() {
             Settings.builder().put(SETTING_NUMBER_OF_SHARDS, 15).build(),
             IndexScopedSettings.DEFAULT_SCOPED_SETTINGS,
             randomShardLimitService(),
-            Collections.emptySet(),
-            false
+            Collections.emptySet()
         );
 
         assertThat(aggregatedIndexSettings.get(SETTING_NUMBER_OF_SHARDS), equalTo("15"));
@@ -957,8 +953,7 @@ public void testTemplateOrder() throws Exception {
             Settings.EMPTY,
             IndexScopedSettings.DEFAULT_SCOPED_SETTINGS,
             randomShardLimitService(),
-            Collections.emptySet(),
-            false
+            Collections.emptySet()
         );
         List<AliasMetadata> resolvedAliases = resolveAndValidateAliases(
             request.index(),
@@ -997,8 +992,7 @@ public void testAggregateIndexSettingsIgnoresTemplatesOnCreateFromSourceIndex()
             Settings.EMPTY,
             IndexScopedSettings.DEFAULT_SCOPED_SETTINGS,
             randomShardLimitService(),
-            Collections.emptySet(),
-            false
+            Collections.emptySet()
         );
 
         assertThat(aggregatedIndexSettings.get("templateSetting"), is(nullValue()));
@@ -1220,8 +1214,7 @@ public void testRemoteStoreNoUserOverrideConflictingReplicationTypeIndexSettings
                 settings,
                 IndexScopedSettings.DEFAULT_SCOPED_SETTINGS,
                 randomShardLimitService(),
-                Collections.emptySet(),
-                false
+                Collections.emptySet()
             )
         );
         assertThat(
@@ -1252,8 +1245,7 @@ public void testRemoteStoreNoUserOverrideExceptReplicationTypeSegmentIndexSettin
             settings,
             IndexScopedSettings.DEFAULT_SCOPED_SETTINGS,
             randomShardLimitService(),
-            Collections.emptySet(),
-            false
+            Collections.emptySet()
         );
         verifyRemoteStoreIndexSettings(
             indexSettings,
@@ -1285,8 +1277,7 @@ public void testRemoteStoreNoUserOverrideIndexSettings() {
             settings,
             IndexScopedSettings.DEFAULT_SCOPED_SETTINGS,
             randomShardLimitService(),
-            Collections.emptySet(),
-            false
+            Collections.emptySet()
         );
         verifyRemoteStoreIndexSettings(
             indexSettings,
@@ -1320,8 +1311,7 @@ public void testRemoteStoreDisabledByUserIndexSettings() {
             settings,
             IndexScopedSettings.DEFAULT_SCOPED_SETTINGS,
             randomShardLimitService(),
-            Collections.emptySet(),
-            false
+            Collections.emptySet()
         );
         verifyRemoteStoreIndexSettings(
             indexSettings,
@@ -1355,8 +1345,7 @@ public void testRemoteStoreTranslogDisabledByUserIndexSettings() {
             settings,
             IndexScopedSettings.DEFAULT_SCOPED_SETTINGS,
             randomShardLimitService(),
-            Collections.emptySet(),
-            false
+            Collections.emptySet()
         );
         verifyRemoteStoreIndexSettings(
             indexSettings,
@@ -1393,8 +1382,7 @@ public void testRemoteStoreOverrideSegmentRepoIndexSettings() {
             settings,
             IndexScopedSettings.DEFAULT_SCOPED_SETTINGS,
             randomShardLimitService(),
-            Collections.emptySet(),
-            false
+            Collections.emptySet()
         );
         verifyRemoteStoreIndexSettings(
             indexSettings,
@@ -1428,8 +1416,7 @@ public void testRemoteStoreOverrideTranslogRepoIndexSettings() {
             settings,
             IndexScopedSettings.DEFAULT_SCOPED_SETTINGS,
             randomShardLimitService(),
-            Collections.emptySet(),
-            false
+            Collections.emptySet()
         );
         verifyRemoteStoreIndexSettings(
             indexSettings,
@@ -1463,8 +1450,7 @@ public void testRemoteStoreOverrideReplicationTypeIndexSettings() {
             settings,
             IndexScopedSettings.DEFAULT_SCOPED_SETTINGS,
             randomShardLimitService(),
-            Collections.emptySet(),
-            false
+            Collections.emptySet()
         );
         verifyRemoteStoreIndexSettings(
             indexSettings,
@@ -1546,8 +1532,7 @@ public void testSoftDeletesDisabledIsRejected() {
                 Settings.EMPTY,
                 IndexScopedSettings.DEFAULT_SCOPED_SETTINGS,
                 randomShardLimitService(),
-                Collections.emptySet(),
-                false
+                Collections.emptySet()
             );
         });
         assertThat(
@@ -1576,8 +1561,7 @@ public void testValidateTranslogRetentionSettings() {
             Settings.EMPTY,
             IndexScopedSettings.DEFAULT_SCOPED_SETTINGS,
             randomShardLimitService(),
-            Collections.emptySet(),
-            false
+            Collections.emptySet()
         );
         assertWarnings(
             "Translog retention settings [index.translog.retention.age] "
@@ -1624,8 +1608,7 @@ public void testDeprecatedSimpleFSStoreSettings() {
             Settings.EMPTY,
             IndexScopedSettings.DEFAULT_SCOPED_SETTINGS,
             randomShardLimitService(),
-            Collections.emptySet(),
-            false
+            Collections.emptySet()
         );
         assertWarnings(
             "[simplefs] is deprecated and will be removed in 2.0. Use [niofs], which offers equal "
@@ -1644,8 +1627,7 @@ public void testClusterReplicationSetting() {
             settings,
             IndexScopedSettings.DEFAULT_SCOPED_SETTINGS,
             randomShardLimitService(),
-            Collections.emptySet(),
-            false
+            Collections.emptySet()
         );
         assertEquals(ReplicationType.SEGMENT.toString(), indexSettings.get(SETTING_REPLICATION_TYPE));
     }
@@ -1665,86 +1647,12 @@ public void testIndexSettingOverridesClusterReplicationSetting() {
             settings,
             IndexScopedSettings.DEFAULT_SCOPED_SETTINGS,
             randomShardLimitService(),
-            Collections.emptySet(),
-            false
+            Collections.emptySet()
         );
         // Verify if index setting overrides cluster replication setting
         assertEquals(ReplicationType.DOCUMENT.toString(), indexSettings.get(SETTING_REPLICATION_TYPE));
     }
 
-    public void testHiddenIndexUsesDocumentReplication() {
-        Settings settings = Settings.builder().put(CLUSTER_REPLICATION_TYPE_SETTING.getKey(), ReplicationType.SEGMENT).build();
-        request = new CreateIndexClusterStateUpdateRequest("create index", "test", "test");
-        final Settings.Builder requestSettings = Settings.builder();
-        // Set index setting replication type as DOCUMENT
-        requestSettings.put("index.hidden", true);
-        request.settings(requestSettings.build());
-        Settings indexSettings = aggregateIndexSettings(
-            ClusterState.EMPTY_STATE,
-            request,
-            Settings.EMPTY,
-            null,
-            settings,
-            IndexScopedSettings.DEFAULT_SCOPED_SETTINGS,
-            randomShardLimitService(),
-            Collections.emptySet(),
-            false
-        );
-        // Verify replication type is Document Replication
-        assertEquals(ReplicationType.DOCUMENT.toString(), indexSettings.get(SETTING_REPLICATION_TYPE));
-    }
-
-    public void testSystemIndexUsesDocumentReplication() {
-        Settings settings = Settings.builder().put(CLUSTER_REPLICATION_TYPE_SETTING.getKey(), ReplicationType.SEGMENT).build();
-        request = new CreateIndexClusterStateUpdateRequest("create index", "test", "test");
-        final Settings.Builder requestSettings = Settings.builder();
-        request.settings(requestSettings.build());
-        // set isSystemIndex parameter as true
-        Settings indexSettings = aggregateIndexSettings(
-            ClusterState.EMPTY_STATE,
-            request,
-            Settings.EMPTY,
-            null,
-            settings,
-            IndexScopedSettings.DEFAULT_SCOPED_SETTINGS,
-            randomShardLimitService(),
-            Collections.emptySet(),
-            true
-        );
-        // Verify replication type is Document Replication
-        assertEquals(ReplicationType.DOCUMENT.toString(), indexSettings.get(SETTING_REPLICATION_TYPE));
-    }
-
-    public void testRemoteStoreDisabledForSystemIndices() {
-        Settings settings = Settings.builder()
-            .put(CLUSTER_REPLICATION_TYPE_SETTING.getKey(), ReplicationType.SEGMENT)
-            .put(CLUSTER_REMOTE_STORE_ENABLED_SETTING.getKey(), true)
-            .put(CLUSTER_REMOTE_STORE_REPOSITORY_SETTING.getKey(), "my-segment-repo-1")
-            .put(CLUSTER_REMOTE_TRANSLOG_STORE_ENABLED_SETTING.getKey(), true)
-            .put(CLUSTER_REMOTE_TRANSLOG_REPOSITORY_SETTING.getKey(), "my-translog-repo-1")
-            .build();
-        FeatureFlagSetter.set(FeatureFlags.REMOTE_STORE);
-
-        request = new CreateIndexClusterStateUpdateRequest("create index", "test", "test");
-        final Settings.Builder requestSettings = Settings.builder();
-        request.settings(requestSettings.build());
-        // set isSystemIndex parameter as true
-        Settings indexSettings = aggregateIndexSettings(
-            ClusterState.EMPTY_STATE,
-            request,
-            Settings.EMPTY,
-            null,
-            settings,
-            IndexScopedSettings.DEFAULT_SCOPED_SETTINGS,
-            randomShardLimitService(),
-            Collections.emptySet(),
-            true
-        );
-        // Verify that remote store is disabled.
-        assertEquals(indexSettings.get(SETTING_REMOTE_STORE_ENABLED), "false");
-        assertEquals(ReplicationType.DOCUMENT.toString(), indexSettings.get(SETTING_REPLICATION_TYPE));
-    }
-
     private IndexTemplateMetadata addMatchingTemplate(Consumer<IndexTemplateMetadata.Builder> configurator) {
         IndexTemplateMetadata.Builder builder = templateMetadataBuilder("template1", "te*");
         configurator.accept(builder);
diff --git a/server/src/test/java/org/opensearch/common/blobstore/fs/FsBlobContainerTests.java b/server/src/test/java/org/opensearch/common/blobstore/fs/FsBlobContainerTests.java
index 6c36368bfe446..4a2eeabeb7e58 100644
--- a/server/src/test/java/org/opensearch/common/blobstore/fs/FsBlobContainerTests.java
+++ b/server/src/test/java/org/opensearch/common/blobstore/fs/FsBlobContainerTests.java
@@ -34,6 +34,9 @@
 import org.apache.lucene.tests.mockfile.FilterFileSystemProvider;
 import org.apache.lucene.tests.mockfile.FilterSeekableByteChannel;
 import org.apache.lucene.tests.util.LuceneTestCase;
+import org.opensearch.action.ActionListener;
+import org.opensearch.common.blobstore.BlobContainer;
+import org.opensearch.common.blobstore.BlobMetadata;
 import org.opensearch.common.blobstore.BlobPath;
 import org.opensearch.common.io.PathUtils;
 import org.opensearch.common.io.PathUtilsForTesting;
@@ -54,10 +57,14 @@
 import java.nio.file.Path;
 import java.nio.file.attribute.FileAttribute;
 import java.nio.file.spi.FileSystemProvider;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
 import java.util.Locale;
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.function.Consumer;
+import java.util.stream.Collectors;
 
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.equalTo;
@@ -118,6 +125,79 @@ public void testIsTempBlobName() {
         assertThat(FsBlobContainer.isTempBlobName(tempBlobName), is(true));
     }
 
+    private void testListBlobsByPrefixInSortedOrder(int limit, BlobContainer.BlobNameSortOrder blobNameSortOrder) throws IOException {
+
+        final Path path = PathUtils.get(createTempDir().toString());
+
+        List<String> blobsInFileSystem = new ArrayList<>();
+        for (int i = 0; i < 10; i++) {
+            final String blobName = randomAlphaOfLengthBetween(10, 20).toLowerCase(Locale.ROOT);
+            final byte[] blobData = randomByteArrayOfLength(randomIntBetween(1, frequently() ? 512 : 1 << 20)); // rarely up to 1mb
+            Files.write(path.resolve(blobName), blobData);
+            blobsInFileSystem.add(blobName);
+        }
+
+        final FsBlobContainer container = new FsBlobContainer(
+            new FsBlobStore(randomIntBetween(1, 8) * 1024, path, false),
+            BlobPath.cleanPath(),
+            path
+        );
+
+        if (limit >= 0) {
+            container.listBlobsByPrefixInSortedOrder(null, limit, blobNameSortOrder, new ActionListener<>() {
+                @Override
+                public void onResponse(List<BlobMetadata> blobMetadata) {
+                    int actualLimit = Math.min(limit, 10);
+                    assertEquals(actualLimit, blobMetadata.size());
+
+                    if (blobNameSortOrder == BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC) {
+                        blobsInFileSystem.sort(String::compareTo);
+                    } else {
+                        blobsInFileSystem.sort(Collections.reverseOrder(String::compareTo));
+                    }
+                    List<String> keys = blobsInFileSystem.subList(0, actualLimit);
+                    assertEquals(keys, blobMetadata.stream().map(BlobMetadata::name).collect(Collectors.toList()));
+                }
+
+                @Override
+                public void onFailure(Exception e) {
+                    fail("blobContainer.listBlobsByPrefixInLexicographicOrder failed with exception: " + e.getMessage());
+                }
+            });
+        } else {
+            assertThrows(
+                IllegalArgumentException.class,
+                () -> container.listBlobsByPrefixInSortedOrder(null, limit, blobNameSortOrder, new ActionListener<>() {
+                    @Override
+                    public void onResponse(List<BlobMetadata> blobMetadata) {}
+
+                    @Override
+                    public void onFailure(Exception e) {}
+                })
+            );
+        }
+    }
+
+    public void testListBlobsByPrefixInLexicographicOrderWithNegativeLimit() throws IOException {
+        testListBlobsByPrefixInSortedOrder(-5, BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC);
+    }
+
+    public void testListBlobsByPrefixInLexicographicOrderWithZeroLimit() throws IOException {
+        testListBlobsByPrefixInSortedOrder(0, BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC);
+    }
+
+    public void testListBlobsByPrefixInLexicographicOrderWithLimitLessThanNumberOfRecords() throws IOException {
+        testListBlobsByPrefixInSortedOrder(8, BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC);
+    }
+
+    public void testListBlobsByPrefixInLexicographicOrderWithLimitNumberOfRecords() throws IOException {
+        testListBlobsByPrefixInSortedOrder(10, BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC);
+    }
+
+    public void testListBlobsByPrefixInLexicographicOrderWithLimitGreaterThanNumberOfRecords() throws IOException {
+        testListBlobsByPrefixInSortedOrder(12, BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC);
+    }
+
     static class MockFileSystemProvider extends FilterFileSystemProvider {
 
         final Consumer<Long> onRead;
diff --git a/server/src/test/java/org/opensearch/common/util/concurrent/ThreadContextTests.java b/server/src/test/java/org/opensearch/common/util/concurrent/ThreadContextTests.java
index 64286e47b4966..dfa239757513e 100644
--- a/server/src/test/java/org/opensearch/common/util/concurrent/ThreadContextTests.java
+++ b/server/src/test/java/org/opensearch/common/util/concurrent/ThreadContextTests.java
@@ -71,6 +71,35 @@ public void testStashContext() {
         assertEquals("1", threadContext.getHeader("default"));
     }
 
+    public void testStashContextWithPersistentHeaders() {
+        Settings build = Settings.builder().put("request.headers.default", "1").build();
+        ThreadContext threadContext = new ThreadContext(build);
+        threadContext.putHeader("foo", "bar");
+        threadContext.putTransient("ctx.foo", 1);
+        threadContext.putPersistent("persistent_foo", "baz");
+        threadContext.putPersistent("ctx.persistent_foo", 10);
+        assertEquals("bar", threadContext.getHeader("foo"));
+        assertEquals(Integer.valueOf(1), threadContext.getTransient("ctx.foo"));
+        assertEquals("1", threadContext.getHeader("default"));
+        try (ThreadContext.StoredContext ctx = threadContext.stashContext()) {
+            assertNull(threadContext.getHeader("foo"));
+            assertNull(threadContext.getTransient("ctx.foo"));
+            assertEquals("1", threadContext.getHeader("default"));
+
+            assertEquals("baz", threadContext.getPersistent("persistent_foo"));
+            assertEquals(Integer.valueOf(10), threadContext.getPersistent("ctx.persistent_foo"));
+            assertNull(threadContext.getPersistent("default"));
+        }
+
+        assertEquals("bar", threadContext.getHeader("foo"));
+        assertEquals(Integer.valueOf(1), threadContext.getTransient("ctx.foo"));
+        assertEquals("1", threadContext.getHeader("default"));
+
+        assertEquals("baz", threadContext.getPersistent("persistent_foo"));
+        assertEquals(Integer.valueOf(10), threadContext.getPersistent("ctx.persistent_foo"));
+        assertNull(threadContext.getPersistent("default"));
+    }
+
     public void testNewContextWithClearedTransients() {
         ThreadContext threadContext = new ThreadContext(Settings.EMPTY);
         threadContext.putTransient("foo", "bar");
diff --git a/server/src/test/java/org/opensearch/extensions/ExtensionsManagerTests.java b/server/src/test/java/org/opensearch/extensions/ExtensionsManagerTests.java
index f8ec138d8eff2..3f61d01166fb9 100644
--- a/server/src/test/java/org/opensearch/extensions/ExtensionsManagerTests.java
+++ b/server/src/test/java/org/opensearch/extensions/ExtensionsManagerTests.java
@@ -45,8 +45,6 @@
 import org.opensearch.client.node.NodeClient;
 import org.opensearch.cluster.ClusterSettingsResponse;
 import org.opensearch.common.util.FeatureFlags;
-import org.opensearch.common.xcontent.json.JsonXContent;
-import org.opensearch.core.xcontent.XContentParser;
 import org.opensearch.env.EnvironmentSettingsResponse;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.cluster.node.DiscoveryNode;
@@ -398,16 +396,6 @@ public void testExtensionDependency() throws Exception {
         }
     }
 
-    public void testParseExtensionDependency() throws Exception {
-        XContentParser parser = createParser(JsonXContent.jsonXContent, "{\"uniqueId\": \"test1\", \"version\": \"2.0.0\"}");
-
-        assertEquals(XContentParser.Token.START_OBJECT, parser.nextToken());
-        ExtensionDependency dependency = ExtensionDependency.parse(parser);
-
-        assertEquals("test1", dependency.getUniqueId());
-        assertEquals(Version.fromString("2.0.0"), dependency.getVersion());
-    }
-
     public void testInitialize() throws Exception {
         ExtensionsManager extensionsManager = new ExtensionsManager(Set.of());
 
@@ -455,8 +443,8 @@ public void testHandleRegisterRestActionsRequest() throws Exception {
         initialize(extensionsManager);
 
         String uniqueIdStr = "uniqueid1";
-        List<String> actionsList = List.of("GET /foo", "PUT /bar", "POST /baz");
-        List<String> deprecatedActionsList = List.of("GET /deprecated/foo", "It's deprecated!");
+        List<String> actionsList = List.of("GET /foo foo", "PUT /bar bar", "POST /baz baz");
+        List<String> deprecatedActionsList = List.of("GET /deprecated/foo foo_deprecated", "It's deprecated!");
         RegisterRestActionsRequest registerActionsRequest = new RegisterRestActionsRequest(uniqueIdStr, actionsList, deprecatedActionsList);
         TransportResponse response = extensionsManager.getRestActionsRequestHandler()
             .handleRegisterRestActionsRequest(registerActionsRequest, actionModule.getDynamicActionRegistry());
diff --git a/server/src/test/java/org/opensearch/extensions/rest/RestInitializeExtensionActionTests.java b/server/src/test/java/org/opensearch/extensions/rest/RestInitializeExtensionActionTests.java
index 8d027b7fca9c2..7dd616c678e74 100644
--- a/server/src/test/java/org/opensearch/extensions/rest/RestInitializeExtensionActionTests.java
+++ b/server/src/test/java/org/opensearch/extensions/rest/RestInitializeExtensionActionTests.java
@@ -9,24 +9,33 @@
 package org.opensearch.extensions.rest;
 
 import java.util.Collections;
+import java.util.List;
+import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.TimeUnit;
+import java.util.function.Function;
 
 import static java.util.Collections.emptyMap;
 import static java.util.Collections.emptySet;
+import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.when;
 
 import org.junit.After;
 import org.junit.Before;
+import org.mockito.Mockito;
 import org.opensearch.Version;
 import org.opensearch.cluster.node.DiscoveryNode;
 import org.opensearch.common.bytes.BytesArray;
 import org.opensearch.common.io.stream.NamedWriteableRegistry;
 import org.opensearch.common.network.NetworkService;
+import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.util.PageCacheRecycler;
 import org.opensearch.common.xcontent.XContentType;
 import org.opensearch.extensions.ExtensionsManager;
+import org.opensearch.extensions.ExtensionsSettings;
 import org.opensearch.indices.breaker.NoneCircuitBreakerService;
 import org.opensearch.rest.RestRequest;
 import org.opensearch.rest.RestStatus;
@@ -88,8 +97,12 @@ public void testRestInitializeExtensionActionResponse() throws Exception {
         ExtensionsManager extensionsManager = mock(ExtensionsManager.class);
         RestInitializeExtensionAction restInitializeExtensionAction = new RestInitializeExtensionAction(extensionsManager);
         final String content = "{\"name\":\"ad-extension\",\"uniqueId\":\"ad-extension\",\"hostAddress\":\"127.0.0.1\","
-            + "\"port\":\"4532\",\"version\":\"1.0\",\"opensearchVersion\":\"3.0.0\","
-            + "\"minimumCompatibleVersion\":\"3.0.0\"}";
+            + "\"port\":\"4532\",\"version\":\"1.0\",\"opensearchVersion\":\""
+            + Version.CURRENT.toString()
+            + "\","
+            + "\"minimumCompatibleVersion\":\""
+            + Version.CURRENT.minimumCompatibilityVersion().toString()
+            + "\"}";
         RestRequest request = new FakeRestRequest.Builder(xContentRegistry()).withContent(new BytesArray(content), XContentType.JSON)
             .withMethod(RestRequest.Method.POST)
             .build();
@@ -106,8 +119,12 @@ public void testRestInitializeExtensionActionFailure() throws Exception {
         RestInitializeExtensionAction restInitializeExtensionAction = new RestInitializeExtensionAction(extensionsManager);
 
         final String content = "{\"name\":\"ad-extension\",\"uniqueId\":\"\",\"hostAddress\":\"127.0.0.1\","
-            + "\"port\":\"4532\",\"version\":\"1.0\",\"opensearchVersion\":\"3.0.0\","
-            + "\"minimumCompatibleVersion\":\"3.0.0\"}";
+            + "\"port\":\"4532\",\"version\":\"1.0\",\"opensearchVersion\":\""
+            + Version.CURRENT.toString()
+            + "\","
+            + "\"minimumCompatibleVersion\":\""
+            + Version.CURRENT.minimumCompatibilityVersion().toString()
+            + "\"}";
         RestRequest request = new FakeRestRequest.Builder(xContentRegistry()).withContent(new BytesArray(content), XContentType.JSON)
             .withMethod(RestRequest.Method.POST)
             .build();
@@ -121,4 +138,98 @@ public void testRestInitializeExtensionActionFailure() throws Exception {
         );
     }
 
+    public void testRestInitializeExtensionActionResponseWithAdditionalSettings() throws Exception {
+        Setting boolSetting = Setting.boolSetting("boolSetting", false, Setting.Property.ExtensionScope);
+        Setting stringSetting = Setting.simpleString("stringSetting", "default", Setting.Property.ExtensionScope);
+        Setting intSetting = Setting.intSetting("intSetting", 0, Setting.Property.ExtensionScope);
+        Setting listSetting = Setting.listSetting(
+            "listSetting",
+            List.of("first", "second", "third"),
+            Function.identity(),
+            Setting.Property.ExtensionScope
+        );
+        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of(boolSetting, stringSetting, intSetting, listSetting));
+        ExtensionsManager spy = spy(extensionsManager);
+
+        // optionally, you can stub out some methods:
+        when(spy.getAdditionalSettings()).thenCallRealMethod();
+        Mockito.doCallRealMethod().when(spy).loadExtension(any(ExtensionsSettings.Extension.class));
+        Mockito.doNothing().when(spy).initialize();
+        RestInitializeExtensionAction restInitializeExtensionAction = new RestInitializeExtensionAction(spy);
+        final String content = "{\"name\":\"ad-extension\",\"uniqueId\":\"ad-extension\",\"hostAddress\":\"127.0.0.1\","
+            + "\"port\":\"4532\",\"version\":\"1.0\",\"opensearchVersion\":\""
+            + Version.CURRENT.toString()
+            + "\","
+            + "\"minimumCompatibleVersion\":\""
+            + Version.CURRENT.minimumCompatibilityVersion().toString()
+            + "\",\"boolSetting\":true,\"stringSetting\":\"customSetting\",\"intSetting\":5,\"listSetting\":[\"one\",\"two\",\"three\"]}";
+        RestRequest request = new FakeRestRequest.Builder(xContentRegistry()).withContent(new BytesArray(content), XContentType.JSON)
+            .withMethod(RestRequest.Method.POST)
+            .build();
+
+        FakeRestChannel channel = new FakeRestChannel(request, false, 0);
+        restInitializeExtensionAction.handleRequest(request, channel, null);
+
+        assertEquals(channel.capturedResponse().status(), RestStatus.ACCEPTED);
+        assertTrue(channel.capturedResponse().content().utf8ToString().contains("A request to initialize an extension has been sent."));
+
+        Optional<ExtensionsSettings.Extension> extension = spy.lookupExtensionSettingsById("ad-extension");
+        assertTrue(extension.isPresent());
+        assertEquals(true, extension.get().getAdditionalSettings().get(boolSetting));
+        assertEquals("customSetting", extension.get().getAdditionalSettings().get(stringSetting));
+        assertEquals(5, extension.get().getAdditionalSettings().get(intSetting));
+
+        List<String> listSettingValue = (List<String>) extension.get().getAdditionalSettings().get(listSetting);
+        assertTrue(listSettingValue.contains("one"));
+        assertTrue(listSettingValue.contains("two"));
+        assertTrue(listSettingValue.contains("three"));
+    }
+
+    public void testRestInitializeExtensionActionResponseWithAdditionalSettingsUsingDefault() throws Exception {
+        Setting boolSetting = Setting.boolSetting("boolSetting", false, Setting.Property.ExtensionScope);
+        Setting stringSetting = Setting.simpleString("stringSetting", "default", Setting.Property.ExtensionScope);
+        Setting intSetting = Setting.intSetting("intSetting", 0, Setting.Property.ExtensionScope);
+        Setting listSetting = Setting.listSetting(
+            "listSetting",
+            List.of("first", "second", "third"),
+            Function.identity(),
+            Setting.Property.ExtensionScope
+        );
+        ExtensionsManager extensionsManager = new ExtensionsManager(Set.of(boolSetting, stringSetting, intSetting, listSetting));
+        ExtensionsManager spy = spy(extensionsManager);
+
+        // optionally, you can stub out some methods:
+        when(spy.getAdditionalSettings()).thenCallRealMethod();
+        Mockito.doCallRealMethod().when(spy).loadExtension(any(ExtensionsSettings.Extension.class));
+        Mockito.doNothing().when(spy).initialize();
+        RestInitializeExtensionAction restInitializeExtensionAction = new RestInitializeExtensionAction(spy);
+        final String content = "{\"name\":\"ad-extension\",\"uniqueId\":\"ad-extension\",\"hostAddress\":\"127.0.0.1\","
+            + "\"port\":\"4532\",\"version\":\"1.0\",\"opensearchVersion\":\""
+            + Version.CURRENT.toString()
+            + "\","
+            + "\"minimumCompatibleVersion\":\""
+            + Version.CURRENT.minimumCompatibilityVersion().toString()
+            + "\"}";
+        RestRequest request = new FakeRestRequest.Builder(xContentRegistry()).withContent(new BytesArray(content), XContentType.JSON)
+            .withMethod(RestRequest.Method.POST)
+            .build();
+
+        FakeRestChannel channel = new FakeRestChannel(request, false, 0);
+        restInitializeExtensionAction.handleRequest(request, channel, null);
+
+        assertEquals(channel.capturedResponse().status(), RestStatus.ACCEPTED);
+        assertTrue(channel.capturedResponse().content().utf8ToString().contains("A request to initialize an extension has been sent."));
+
+        Optional<ExtensionsSettings.Extension> extension = spy.lookupExtensionSettingsById("ad-extension");
+        assertTrue(extension.isPresent());
+        assertEquals(false, extension.get().getAdditionalSettings().get(boolSetting));
+        assertEquals("default", extension.get().getAdditionalSettings().get(stringSetting));
+        assertEquals(0, extension.get().getAdditionalSettings().get(intSetting));
+
+        List<String> listSettingValue = (List<String>) extension.get().getAdditionalSettings().get(listSetting);
+        assertTrue(listSettingValue.contains("first"));
+        assertTrue(listSettingValue.contains("second"));
+        assertTrue(listSettingValue.contains("third"));
+    }
+
 }
diff --git a/server/src/test/java/org/opensearch/extensions/rest/RestSendToExtensionActionTests.java b/server/src/test/java/org/opensearch/extensions/rest/RestSendToExtensionActionTests.java
index fe8792b36f048..23a9169b91e21 100644
--- a/server/src/test/java/org/opensearch/extensions/rest/RestSendToExtensionActionTests.java
+++ b/server/src/test/java/org/opensearch/extensions/rest/RestSendToExtensionActionTests.java
@@ -135,8 +135,8 @@ public void tearDown() throws Exception {
     public void testRestSendToExtensionAction() throws Exception {
         RegisterRestActionsRequest registerRestActionRequest = new RegisterRestActionsRequest(
             "uniqueid1",
-            List.of("GET /foo", "PUT /bar", "POST /baz"),
-            List.of("GET /deprecated/foo", "It's deprecated!")
+            List.of("GET /foo foo", "PUT /bar bar", "POST /baz baz"),
+            List.of("GET /deprecated/foo foo_deprecated", "Its deprecated")
         );
         RestSendToExtensionAction restSendToExtensionAction = new RestSendToExtensionAction(
             registerRestActionRequest,
@@ -180,9 +180,70 @@ public void testRestSendToExtensionActionWithNamedRoute() throws Exception {
         assertEquals("send_to_extension_action", restSendToExtensionAction.getName());
         List<NamedRoute> expected = new ArrayList<>();
         String uriPrefix = "/_extensions/_uniqueid1";
-        expected.add(new NamedRoute(Method.GET, uriPrefix + "/foo", "foo"));
-        expected.add(new NamedRoute(Method.PUT, uriPrefix + "/bar", "bar"));
-        expected.add(new NamedRoute(Method.POST, uriPrefix + "/baz", "baz"));
+        NamedRoute nr1 = new NamedRoute.Builder().method(Method.GET).path(uriPrefix + "/foo").uniqueName("foo").build();
+
+        NamedRoute nr2 = new NamedRoute.Builder().method(Method.PUT).path(uriPrefix + "/bar").uniqueName("bar").build();
+
+        NamedRoute nr3 = new NamedRoute.Builder().method(Method.POST).path(uriPrefix + "/baz").uniqueName("baz").build();
+
+        expected.add(nr1);
+        expected.add(nr2);
+        expected.add(nr3);
+
+        List<Route> routes = restSendToExtensionAction.routes();
+        assertEquals(expected.size(), routes.size());
+        List<String> expectedPaths = expected.stream().map(Route::getPath).collect(Collectors.toList());
+        List<String> paths = routes.stream().map(Route::getPath).collect(Collectors.toList());
+        List<Method> expectedMethods = expected.stream().map(Route::getMethod).collect(Collectors.toList());
+        List<Method> methods = routes.stream().map(Route::getMethod).collect(Collectors.toList());
+        List<String> expectedNames = expected.stream().map(NamedRoute::name).collect(Collectors.toList());
+        List<String> names = routes.stream().map(r -> ((NamedRoute) r).name()).collect(Collectors.toList());
+        assertTrue(paths.containsAll(expectedPaths));
+        assertTrue(expectedPaths.containsAll(paths));
+        assertTrue(methods.containsAll(expectedMethods));
+        assertTrue(expectedMethods.containsAll(methods));
+        assertTrue(expectedNames.containsAll(names));
+    }
+
+    public void testRestSendToExtensionActionWithNamedRouteAndLegacyActionName() throws Exception {
+        RegisterRestActionsRequest registerRestActionRequest = new RegisterRestActionsRequest(
+            "uniqueid1",
+            List.of(
+                "GET /foo foo cluster:admin/opensearch/abc/foo",
+                "PUT /bar bar cluster:admin/opensearch/jkl/bar,cluster:admin/opendistro/mno/bar*",
+                "POST /baz baz cluster:admin/opensearch/xyz/baz"
+            ),
+            List.of("GET /deprecated/foo foo_deprecated cluster:admin/opensearch/abc/foo_deprecated", "It's deprecated!")
+        );
+        RestSendToExtensionAction restSendToExtensionAction = new RestSendToExtensionAction(
+            registerRestActionRequest,
+            discoveryExtensionNode,
+            transportService,
+            dynamicActionRegistry
+        );
+
+        assertEquals("send_to_extension_action", restSendToExtensionAction.getName());
+        List<NamedRoute> expected = new ArrayList<>();
+        String uriPrefix = "/_extensions/_uniqueid1";
+        NamedRoute nr1 = new NamedRoute.Builder().method(Method.GET)
+            .path(uriPrefix + "/foo")
+            .uniqueName("foo")
+            .legacyActionNames(Set.of("cluster:admin/opensearch/abc/foo"))
+            .build();
+        NamedRoute nr2 = new NamedRoute.Builder().method(Method.PUT)
+            .path(uriPrefix + "/bar")
+            .uniqueName("bar")
+            .legacyActionNames(Set.of("cluster:admin/opensearch/jkl/bar", "cluster:admin/opendistro/mno/bar*"))
+            .build();
+        NamedRoute nr3 = new NamedRoute.Builder().method(Method.POST)
+            .path(uriPrefix + "/baz")
+            .uniqueName("baz")
+            .legacyActionNames(Set.of("cluster:admin/opensearch/xyz/baz"))
+            .build();
+
+        expected.add(nr1);
+        expected.add(nr2);
+        expected.add(nr3);
 
         List<Route> routes = restSendToExtensionAction.routes();
         assertEquals(expected.size(), routes.size());
@@ -192,11 +253,26 @@ public void testRestSendToExtensionActionWithNamedRoute() throws Exception {
         List<Method> methods = routes.stream().map(Route::getMethod).collect(Collectors.toList());
         List<String> expectedNames = expected.stream().map(NamedRoute::name).collect(Collectors.toList());
         List<String> names = routes.stream().map(r -> ((NamedRoute) r).name()).collect(Collectors.toList());
+        Set<String> expectedActionNames = expected.stream().flatMap(nr -> nr.actionNames().stream()).collect(Collectors.toSet());
+        Set<String> actionNames = routes.stream().flatMap(nr -> ((NamedRoute) nr).actionNames().stream()).collect(Collectors.toSet());
         assertTrue(paths.containsAll(expectedPaths));
         assertTrue(expectedPaths.containsAll(paths));
         assertTrue(methods.containsAll(expectedMethods));
         assertTrue(expectedMethods.containsAll(methods));
         assertTrue(expectedNames.containsAll(names));
+        assertTrue(expectedActionNames.containsAll(actionNames));
+    }
+
+    public void testRestSendToExtensionActionWithoutUniqueNameShouldFail() {
+        RegisterRestActionsRequest registerRestActionRequest = new RegisterRestActionsRequest(
+            "uniqueid1",
+            List.of("GET /foo", "PUT /bar"),
+            List.of()
+        );
+        expectThrows(
+            IllegalArgumentException.class,
+            () -> new RestSendToExtensionAction(registerRestActionRequest, discoveryExtensionNode, transportService, dynamicActionRegistry)
+        );
     }
 
     public void testRestSendToExtensionMultipleNamedRoutesWithSameName() throws Exception {
@@ -211,6 +287,18 @@ public void testRestSendToExtensionMultipleNamedRoutesWithSameName() throws Exce
         );
     }
 
+    public void testRestSendToExtensionMultipleNamedRoutesWithSameLegacyActionName() throws Exception {
+        RegisterRestActionsRequest registerRestActionRequest = new RegisterRestActionsRequest(
+            "uniqueid1",
+            List.of("GET /foo foo cluster:admin/opensearch/abc/foo", "PUT /bar bar cluster:admin/opensearch/abc/foo"),
+            List.of()
+        );
+        expectThrows(
+            IllegalArgumentException.class,
+            () -> new RestSendToExtensionAction(registerRestActionRequest, discoveryExtensionNode, transportService, dynamicActionRegistry)
+        );
+    }
+
     public void testRestSendToExtensionMultipleRoutesWithSameMethodAndPath() throws Exception {
         RegisterRestActionsRequest registerRestActionRequest = new RegisterRestActionsRequest(
             "uniqueid1",
@@ -226,7 +314,7 @@ public void testRestSendToExtensionMultipleRoutesWithSameMethodAndPath() throws
     public void testRestSendToExtensionMultipleRoutesWithSameMethodAndPathWithDifferentPathParams() throws Exception {
         RegisterRestActionsRequest registerRestActionRequest = new RegisterRestActionsRequest(
             "uniqueid1",
-            List.of("GET /foo/{path_param1}", "GET /foo/{path_param2}"),
+            List.of("GET /foo/{path_param1} fooWithParam", "GET /foo/{path_param2} listFooWithParam"),
             List.of()
         );
         expectThrows(
@@ -235,12 +323,13 @@ public void testRestSendToExtensionMultipleRoutesWithSameMethodAndPathWithDiffer
         );
     }
 
-    public void testRestSendToExtensionMultipleRoutesWithSameMethodAndPathWithPathParams() throws Exception {
+    public void testRestSendToExtensionMultipleRoutesWithSameMethodAndPathWithPathParams() {
         RegisterRestActionsRequest registerRestActionRequest = new RegisterRestActionsRequest(
             "uniqueid1",
-            List.of("GET /foo/{path_param}", "GET /foo/{path_param}/list"),
+            List.of("GET /foo/{path_param} fooWithParam", "GET /foo/{path_param}/list listFooWithParam"),
             List.of()
         );
+
         try {
             new RestSendToExtensionAction(registerRestActionRequest, discoveryExtensionNode, transportService, dynamicActionRegistry);
         } catch (IllegalArgumentException e) {
@@ -285,8 +374,8 @@ public void testRestSendToExtensionWithNamedRouteCollidingWithNativeTransportAct
     public void testRestSendToExtensionActionFilterHeaders() throws Exception {
         RegisterRestActionsRequest registerRestActionRequest = new RegisterRestActionsRequest(
             "uniqueid1",
-            List.of("GET /foo", "PUT /bar", "POST /baz"),
-            List.of("GET /deprecated/foo", "It's deprecated!")
+            List.of("GET /foo foo", "PUT /bar bar", "POST /baz baz"),
+            List.of("GET /deprecated/foo foo_deprecated", "It's deprecated!")
         );
         RestSendToExtensionAction restSendToExtensionAction = new RestSendToExtensionAction(
             registerRestActionRequest,
diff --git a/server/src/test/java/org/opensearch/extensions/rest/RouteHandlerTests.java b/server/src/test/java/org/opensearch/extensions/rest/RouteHandlerTests.java
deleted file mode 100644
index 855296b2038f0..0000000000000
--- a/server/src/test/java/org/opensearch/extensions/rest/RouteHandlerTests.java
+++ /dev/null
@@ -1,36 +0,0 @@
-/*
- * SPDX-License-Identifier: Apache-2.0
- *
- * The OpenSearch Contributors require contributions made to
- * this file be licensed under the Apache-2.0 license or a
- * compatible open source license.
- */
-
-package org.opensearch.extensions.rest;
-
-import org.opensearch.rest.RestRequest;
-import org.opensearch.rest.RestStatus;
-import org.opensearch.test.OpenSearchTestCase;
-
-public class RouteHandlerTests extends OpenSearchTestCase {
-    public void testUnnamedRouteHandler() {
-        RouteHandler rh = new RouteHandler(
-            RestRequest.Method.GET,
-            "/foo/bar",
-            req -> new ExtensionRestResponse(req, RestStatus.OK, "content")
-        );
-
-        assertEquals(null, rh.name());
-    }
-
-    public void testNamedRouteHandler() {
-        RouteHandler rh = new RouteHandler(
-            "foo",
-            RestRequest.Method.GET,
-            "/foo/bar",
-            req -> new ExtensionRestResponse(req, RestStatus.OK, "content")
-        );
-
-        assertEquals("foo", rh.name());
-    }
-}
diff --git a/server/src/test/java/org/opensearch/index/IndexModuleTests.java b/server/src/test/java/org/opensearch/index/IndexModuleTests.java
index d9d87196ca289..32b8fb5a4dc62 100644
--- a/server/src/test/java/org/opensearch/index/IndexModuleTests.java
+++ b/server/src/test/java/org/opensearch/index/IndexModuleTests.java
@@ -252,7 +252,7 @@ private IndexService newIndexService(IndexModule module) throws IOException {
             writableRegistry(),
             () -> false,
             null,
-            new RemoteSegmentStoreDirectoryFactory(() -> repositoriesService),
+            new RemoteSegmentStoreDirectoryFactory(() -> repositoriesService, threadPool),
             translogFactorySupplier
         );
     }
diff --git a/server/src/test/java/org/opensearch/index/mapper/FlatObjectFieldTypeTests.java b/server/src/test/java/org/opensearch/index/mapper/FlatObjectFieldTypeTests.java
new file mode 100644
index 0000000000000..9ec053dc59d10
--- /dev/null
+++ b/server/src/test/java/org/opensearch/index/mapper/FlatObjectFieldTypeTests.java
@@ -0,0 +1,134 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.index.mapper;
+
+import org.apache.lucene.index.Term;
+import org.apache.lucene.search.TermQuery;
+import org.opensearch.Version;
+import org.opensearch.cluster.metadata.IndexMetadata;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.index.analysis.AnalyzerScope;
+import org.opensearch.index.analysis.NamedAnalyzer;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+public class FlatObjectFieldTypeTests extends FieldTypeTestCase {
+    private static MappedFieldType getFlatParentFieldType(String fieldName) {
+        Settings settings = Settings.builder().put(IndexMetadata.SETTING_VERSION_CREATED, Version.CURRENT.id).build();
+        Mapper.BuilderContext context = new Mapper.BuilderContext(settings, new ContentPath());
+        MappedFieldType flatParentFieldType = new FlatObjectFieldMapper.Builder(fieldName).build(context).fieldType();
+        return flatParentFieldType;
+    }
+
+    public void testFetchSourceValue() throws IOException {
+        MappedFieldType mapper = getFlatParentFieldType("field");
+
+        Map<String, Object> jsonPoint = new HashMap<>();
+        jsonPoint.put("type", "flat_object");
+        jsonPoint.put("coordinates", Arrays.asList(42.0, 27.1));
+        Map<String, Object> otherJsonPoint = new HashMap<>();
+        otherJsonPoint.put("type", "Point");
+        otherJsonPoint.put("coordinates", Arrays.asList(30.0, 50.0));
+
+        ArrayList<String> jsonPointList = new ArrayList<>();
+        jsonPointList.add(jsonPoint.toString());
+
+        ArrayList<String> otherJsonPointList = new ArrayList<>();
+        otherJsonPointList.add(otherJsonPoint.toString());
+
+        assertEquals(jsonPointList, fetchSourceValue(mapper, jsonPoint, null));
+        assertEquals(otherJsonPointList, fetchSourceValue(mapper, otherJsonPoint, null));
+
+    }
+
+    public void testDirectSubfield() {
+        {
+            MappedFieldType flatParentFieldType = getFlatParentFieldType("field");
+
+            // when searching for "foo" in "field", the directSubfield is field._value field
+            String searchFieldName = ((FlatObjectFieldMapper.FlatObjectFieldType) flatParentFieldType).directSubfield();
+            assertEquals("field._value", searchFieldName);
+
+            MappedFieldType dynamicMappedFieldType = new FlatObjectFieldMapper.FlatObjectFieldType("bar", flatParentFieldType.name());
+            // when searching for "foo" in "field.bar", the directSubfield is field._valueAndPath field
+            String searchFieldNameDocPath = ((FlatObjectFieldMapper.FlatObjectFieldType) dynamicMappedFieldType).directSubfield();
+            assertEquals("field._valueAndPath", searchFieldNameDocPath);
+        }
+        {
+            NamedAnalyzer analyzer = new NamedAnalyzer("default", AnalyzerScope.INDEX, null);
+            MappedFieldType ft = new FlatObjectFieldMapper.FlatObjectFieldType("field", analyzer);
+            assertEquals("field._value", ((FlatObjectFieldMapper.FlatObjectFieldType) ft).directSubfield());
+        }
+    }
+
+    public void testRewriteValue() {
+        MappedFieldType flatParentFieldType = getFlatParentFieldType("field");
+
+        // when searching for "foo" in "field", the rewrite value is "foo"
+        String searchValues = ((FlatObjectFieldMapper.FlatObjectFieldType) flatParentFieldType).rewriteValue("foo");
+        assertEquals("foo", searchValues);
+
+        MappedFieldType dynamicMappedFieldType = new FlatObjectFieldMapper.FlatObjectFieldType("field.bar", flatParentFieldType.name());
+
+        // when searching for "foo" in "field.bar", the rewrite value is "field.bar=foo"
+        String searchFieldNameDocPath = ((FlatObjectFieldMapper.FlatObjectFieldType) dynamicMappedFieldType).directSubfield();
+        String searchValuesDocPath = ((FlatObjectFieldMapper.FlatObjectFieldType) dynamicMappedFieldType).rewriteValue("foo");
+        assertEquals("field.bar=foo", searchValuesDocPath);
+    }
+
+    public void testTermQuery() {
+
+        MappedFieldType flatParentFieldType = getFlatParentFieldType("field");
+
+        // when searching for "foo" in "field", the term query is directed to search "foo" in field._value field
+        String searchFieldName = ((FlatObjectFieldMapper.FlatObjectFieldType) flatParentFieldType).directSubfield();
+        String searchValues = ((FlatObjectFieldMapper.FlatObjectFieldType) flatParentFieldType).rewriteValue("foo");
+        assertEquals("foo", searchValues);
+        assertEquals(new TermQuery(new Term(searchFieldName, searchValues)), flatParentFieldType.termQuery(searchValues, null));
+
+        MappedFieldType dynamicMappedFieldType = new FlatObjectFieldMapper.FlatObjectFieldType("field.bar", flatParentFieldType.name());
+
+        // when searching for "foo" in "field.bar", the term query is directed to search in field._valueAndPath field
+        String searchFieldNameDocPath = ((FlatObjectFieldMapper.FlatObjectFieldType) dynamicMappedFieldType).directSubfield();
+        String searchValuesDocPath = ((FlatObjectFieldMapper.FlatObjectFieldType) dynamicMappedFieldType).rewriteValue("foo");
+        assertEquals("field.bar=foo", searchValuesDocPath);
+        assertEquals(new TermQuery(new Term(searchFieldNameDocPath, searchValuesDocPath)), dynamicMappedFieldType.termQuery("foo", null));
+
+        MappedFieldType unsearchable = new FlatObjectFieldMapper.FlatObjectFieldType("field", false, true, Collections.emptyMap());
+        IllegalArgumentException e = expectThrows(IllegalArgumentException.class, () -> unsearchable.termQuery("bar", null));
+        assertEquals("Cannot search on field [field] since it is not indexed.", e.getMessage());
+    }
+
+    public void testExistsQuery() {
+        {
+            MappedFieldType ft = getFlatParentFieldType("field");
+            // when checking on the flat_object field name "field", check if exist in the field mapper names
+            assertEquals(new TermQuery(new Term(FieldNamesFieldMapper.NAME, "field")), ft.existsQuery(null));
+
+            // when checking if a subfield within the flat_object, for example, "field.bar", use term query in the flat_object field
+            MappedFieldType dynamicMappedFieldType = new FlatObjectFieldMapper.FlatObjectFieldType("field.bar", ft.name());
+            assertEquals(new TermQuery(new Term("field", "field.bar")), dynamicMappedFieldType.existsQuery(null));
+
+        }
+        {
+            FlatObjectFieldMapper.FlatObjectFieldType ft = new FlatObjectFieldMapper.FlatObjectFieldType(
+                "field",
+                true,
+                false,
+                Collections.emptyMap()
+            );
+            assertEquals(new TermQuery(new Term(FieldNamesFieldMapper.NAME, "field")), ft.existsQuery(null));
+        }
+    }
+}
diff --git a/server/src/test/java/org/opensearch/index/remote/RemoteStoreUtilsTests.java b/server/src/test/java/org/opensearch/index/remote/RemoteStoreUtilsTests.java
new file mode 100644
index 0000000000000..5b9135afb66f3
--- /dev/null
+++ b/server/src/test/java/org/opensearch/index/remote/RemoteStoreUtilsTests.java
@@ -0,0 +1,41 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.index.remote;
+
+import org.opensearch.test.OpenSearchTestCase;
+
+public class RemoteStoreUtilsTests extends OpenSearchTestCase {
+
+    public void testInvertToStrInvalid() {
+        assertThrows(IllegalArgumentException.class, () -> RemoteStoreUtils.invertLong(-1));
+    }
+
+    public void testInvertToStrValid() {
+        assertEquals("9223372036854774573", RemoteStoreUtils.invertLong(1234));
+        assertEquals("0000000000000001234", RemoteStoreUtils.invertLong(9223372036854774573L));
+    }
+
+    public void testInvertToLongInvalid() {
+        assertThrows(IllegalArgumentException.class, () -> RemoteStoreUtils.invertLong("-5"));
+    }
+
+    public void testInvertToLongValid() {
+        assertEquals(1234, RemoteStoreUtils.invertLong("9223372036854774573"));
+        assertEquals(9223372036854774573L, RemoteStoreUtils.invertLong("0000000000000001234"));
+    }
+
+    public void testinvert() {
+        assertEquals(0, RemoteStoreUtils.invertLong(RemoteStoreUtils.invertLong(0)));
+        assertEquals(Long.MAX_VALUE, RemoteStoreUtils.invertLong(RemoteStoreUtils.invertLong(Long.MAX_VALUE)));
+        for (int i = 0; i < 10; i++) {
+            long num = randomLongBetween(1, Long.MAX_VALUE);
+            assertEquals(num, RemoteStoreUtils.invertLong(RemoteStoreUtils.invertLong(num)));
+        }
+    }
+}
diff --git a/server/src/test/java/org/opensearch/index/store/RemoteDirectoryTests.java b/server/src/test/java/org/opensearch/index/store/RemoteDirectoryTests.java
index 15f1585bd1477..8ee5fcf0da9d7 100644
--- a/server/src/test/java/org/opensearch/index/store/RemoteDirectoryTests.java
+++ b/server/src/test/java/org/opensearch/index/store/RemoteDirectoryTests.java
@@ -12,6 +12,8 @@
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.IndexOutput;
 import org.junit.Before;
+import org.opensearch.action.ActionListener;
+import org.opensearch.action.LatchedActionListener;
 import org.opensearch.common.blobstore.BlobContainer;
 import org.opensearch.common.blobstore.BlobMetadata;
 import org.opensearch.common.blobstore.support.PlainBlobMetadata;
@@ -23,15 +25,19 @@
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
-import static org.mockito.Mockito.mock;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.when;
+import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.doThrow;
+import static org.mockito.Mockito.doAnswer;
 
 public class RemoteDirectoryTests extends OpenSearchTestCase {
     private BlobContainer blobContainer;
@@ -146,6 +152,54 @@ public void testFileLengthIOException() throws IOException {
         assertThrows(IOException.class, () -> remoteDirectory.fileLength("segment_1"));
     }
 
+    public void testListFilesByPrefixInLexicographicOrder() throws IOException {
+        doAnswer(invocation -> {
+            LatchedActionListener<List<BlobMetadata>> latchedActionListener = invocation.getArgument(3);
+            latchedActionListener.onResponse(List.of(new PlainBlobMetadata("metadata_1", 1)));
+            return null;
+        }).when(blobContainer)
+            .listBlobsByPrefixInSortedOrder(
+                eq("metadata"),
+                eq(1),
+                eq(BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC),
+                any(ActionListener.class)
+            );
+
+        assertEquals(List.of("metadata_1"), remoteDirectory.listFilesByPrefixInLexicographicOrder("metadata", 1));
+    }
+
+    public void testListFilesByPrefixInLexicographicOrderEmpty() throws IOException {
+        doAnswer(invocation -> {
+            LatchedActionListener<List<BlobMetadata>> latchedActionListener = invocation.getArgument(3);
+            latchedActionListener.onResponse(List.of());
+            return null;
+        }).when(blobContainer)
+            .listBlobsByPrefixInSortedOrder(
+                eq("metadata"),
+                eq(1),
+                eq(BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC),
+                any(ActionListener.class)
+            );
+
+        assertEquals(List.of(), remoteDirectory.listFilesByPrefixInLexicographicOrder("metadata", 1));
+    }
+
+    public void testListFilesByPrefixInLexicographicOrderException() {
+        doAnswer(invocation -> {
+            LatchedActionListener<List<BlobMetadata>> latchedActionListener = invocation.getArgument(3);
+            latchedActionListener.onFailure(new IOException("Error"));
+            return null;
+        }).when(blobContainer)
+            .listBlobsByPrefixInSortedOrder(
+                eq("metadata"),
+                eq(1),
+                eq(BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC),
+                any(ActionListener.class)
+            );
+
+        assertThrows(IOException.class, () -> remoteDirectory.listFilesByPrefixInLexicographicOrder("metadata", 1));
+    }
+
     public void testGetPendingDeletions() {
         assertThrows(UnsupportedOperationException.class, () -> remoteDirectory.getPendingDeletions());
     }
@@ -165,5 +219,4 @@ public void testRename() {
     public void testObtainLock() {
         assertThrows(UnsupportedOperationException.class, () -> remoteDirectory.obtainLock("segment_1"));
     }
-
 }
diff --git a/server/src/test/java/org/opensearch/index/store/RemoteSegmentStoreDirectoryFactoryTests.java b/server/src/test/java/org/opensearch/index/store/RemoteSegmentStoreDirectoryFactoryTests.java
index 7a9cbc12d823b..bf4b2a14f2567 100644
--- a/server/src/test/java/org/opensearch/index/store/RemoteSegmentStoreDirectoryFactoryTests.java
+++ b/server/src/test/java/org/opensearch/index/store/RemoteSegmentStoreDirectoryFactoryTests.java
@@ -11,8 +11,11 @@
 import org.apache.lucene.store.Directory;
 import org.junit.Before;
 import org.mockito.ArgumentCaptor;
+import org.opensearch.action.ActionListener;
+import org.opensearch.action.LatchedActionListener;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.common.blobstore.BlobContainer;
+import org.opensearch.common.blobstore.BlobMetadata;
 import org.opensearch.common.blobstore.BlobPath;
 import org.opensearch.common.blobstore.BlobStore;
 import org.opensearch.common.settings.Settings;
@@ -24,31 +27,35 @@
 import org.opensearch.repositories.blobstore.BlobStoreRepository;
 import org.opensearch.test.IndexSettingsModule;
 import org.opensearch.test.OpenSearchTestCase;
+import org.opensearch.threadpool.ThreadPool;
 
 import java.io.IOException;
 import java.nio.file.Path;
-import java.util.Collections;
 import java.util.List;
 import java.util.function.Supplier;
 
 import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.doAnswer;
 
 public class RemoteSegmentStoreDirectoryFactoryTests extends OpenSearchTestCase {
 
     private Supplier<RepositoriesService> repositoriesServiceSupplier;
     private RepositoriesService repositoriesService;
+    private ThreadPool threadPool;
     private RemoteSegmentStoreDirectoryFactory remoteSegmentStoreDirectoryFactory;
 
     @Before
     public void setup() {
         repositoriesServiceSupplier = mock(Supplier.class);
         repositoriesService = mock(RepositoriesService.class);
+        threadPool = mock(ThreadPool.class);
         when(repositoriesServiceSupplier.get()).thenReturn(repositoriesService);
-        remoteSegmentStoreDirectoryFactory = new RemoteSegmentStoreDirectoryFactory(repositoriesServiceSupplier);
+        remoteSegmentStoreDirectoryFactory = new RemoteSegmentStoreDirectoryFactory(repositoriesServiceSupplier, threadPool);
     }
 
     public void testNewDirectory() throws IOException {
@@ -65,7 +72,12 @@ public void testNewDirectory() throws IOException {
         when(repository.blobStore()).thenReturn(blobStore);
         when(repository.basePath()).thenReturn(new BlobPath().add("base_path"));
         when(blobStore.blobContainer(any())).thenReturn(blobContainer);
-        when(blobContainer.listBlobs()).thenReturn(Collections.emptyMap());
+        doAnswer(invocation -> {
+            LatchedActionListener<List<BlobMetadata>> latchedActionListener = invocation.getArgument(3);
+            latchedActionListener.onResponse(List.of());
+            return null;
+        }).when(blobContainer)
+            .listBlobsByPrefixInSortedOrder(any(), eq(1), eq(BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC), any(ActionListener.class));
 
         when(repositoriesService.repository("remote_store_repository")).thenReturn(repository);
 
@@ -78,7 +90,12 @@ public void testNewDirectory() throws IOException {
             assertEquals("base_path/uuid_1/0/segments/metadata/", blobPaths.get(1).buildAsString());
             assertEquals("base_path/uuid_1/0/segments/lock_files/", blobPaths.get(2).buildAsString());
 
-            verify(blobContainer).listBlobsByPrefix(RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX);
+            verify(blobContainer).listBlobsByPrefixInSortedOrder(
+                eq(RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX),
+                eq(1),
+                eq(BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC),
+                any()
+            );
             verify(repositoriesService, times(2)).repository("remote_store_repository");
         }
     }
diff --git a/server/src/test/java/org/opensearch/index/store/RemoteSegmentStoreDirectoryTests.java b/server/src/test/java/org/opensearch/index/store/RemoteSegmentStoreDirectoryTests.java
index 3417e7b0aee04..c37893877253e 100644
--- a/server/src/test/java/org/opensearch/index/store/RemoteSegmentStoreDirectoryTests.java
+++ b/server/src/test/java/org/opensearch/index/store/RemoteSegmentStoreDirectoryTests.java
@@ -30,12 +30,15 @@
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.common.lucene.store.ByteArrayIndexInput;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.concurrent.OpenSearchExecutors;
 import org.opensearch.index.engine.NRTReplicationEngineFactory;
+import org.opensearch.index.remote.RemoteStoreUtils;
 import org.opensearch.index.shard.IndexShard;
 import org.opensearch.index.shard.IndexShardTestCase;
 import org.opensearch.index.store.lockmanager.RemoteStoreMetadataLockManager;
 import org.opensearch.index.store.remote.metadata.RemoteSegmentMetadata;
 import org.opensearch.index.store.remote.metadata.RemoteSegmentMetadataHandler;
+import org.opensearch.threadpool.ThreadPool;
 
 import java.io.IOException;
 import java.nio.file.NoSuchFileException;
@@ -45,6 +48,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.ExecutorService;
 
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
@@ -56,6 +60,7 @@
 import static org.mockito.Mockito.doThrow;
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.doReturn;
+import static org.hamcrest.CoreMatchers.is;
 
 public class RemoteSegmentStoreDirectoryTests extends IndexShardTestCase {
     private RemoteDirectory remoteDataDirectory;
@@ -65,21 +70,35 @@ public class RemoteSegmentStoreDirectoryTests extends IndexShardTestCase {
     private RemoteSegmentStoreDirectory remoteSegmentStoreDirectory;
     private IndexShard indexShard;
     private SegmentInfos segmentInfos;
+    private ThreadPool threadPool;
+
+    private final String metadataFilename = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(12, 23, 34, 1, 1);
+    private final String metadataFilename2 = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(12, 13, 34, 1, 1);
+    private final String metadataFilename3 = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(10, 38, 34, 1, 1);
 
     @Before
     public void setup() throws IOException {
         remoteDataDirectory = mock(RemoteDirectory.class);
         remoteMetadataDirectory = mock(RemoteDirectory.class);
         mdLockManager = mock(RemoteStoreMetadataLockManager.class);
+        threadPool = mock(ThreadPool.class);
 
-        remoteSegmentStoreDirectory = new RemoteSegmentStoreDirectory(remoteDataDirectory, remoteMetadataDirectory, mdLockManager);
+        remoteSegmentStoreDirectory = new RemoteSegmentStoreDirectory(
+            remoteDataDirectory,
+            remoteMetadataDirectory,
+            mdLockManager,
+            threadPool
+        );
 
         Settings indexSettings = Settings.builder().put(IndexMetadata.SETTING_VERSION_CREATED, org.opensearch.Version.CURRENT).build();
+        ExecutorService executorService = OpenSearchExecutors.newDirectExecutorService();
 
         indexShard = newStartedShard(false, indexSettings, new NRTReplicationEngineFactory());
         try (Store store = indexShard.store()) {
             segmentInfos = store.readLastCommittedSegmentsInfo();
         }
+
+        when(threadPool.executor(ThreadPool.Names.REMOTE_PURGE)).thenReturn(executorService);
     }
 
     @After
@@ -105,50 +124,16 @@ public void testUploadedSegmentMetadataFromString() {
         assertEquals("_0.cfe::_0.cfe__uuidxyz::4567::372000", metadata.toString());
     }
 
-    public void testGetMetadataFilename() {
-        // Generation 23 is replaced by n due to radix 32
-        assertEquals(
-            RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX + "__12__n__uuid1",
-            RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(12, 23, "uuid1")
-        );
-    }
-
     public void testGetPrimaryTermGenerationUuid() {
-        String[] filenameTokens = "abc__12__n__uuid_xyz".split(RemoteSegmentStoreDirectory.MetadataFilenameUtils.SEPARATOR);
+        String[] filenameTokens = "abc__9223372036854775795__9223372036854775784__uuid_xyz".split(
+            RemoteSegmentStoreDirectory.MetadataFilenameUtils.SEPARATOR
+        );
         assertEquals(12, RemoteSegmentStoreDirectory.MetadataFilenameUtils.getPrimaryTerm(filenameTokens));
         assertEquals(23, RemoteSegmentStoreDirectory.MetadataFilenameUtils.getGeneration(filenameTokens));
-        assertEquals("uuid_xyz", RemoteSegmentStoreDirectory.MetadataFilenameUtils.getUuid(filenameTokens));
-    }
-
-    public void testMetadataFilenameComparator() {
-        List<String> metadataFilenames = new ArrayList<>(
-            List.of(
-                "abc__10__20__uuid1",
-                "abc__12__2__uuid2",
-                "pqr__1__1__uuid0",
-                "abc__3__n__uuid3",
-                "abc__10__8__uuid8",
-                "abc__3__a__uuid4",
-                "abc__3__a__uuid5"
-            )
-        );
-        metadataFilenames.sort(RemoteSegmentStoreDirectory.METADATA_FILENAME_COMPARATOR);
-        assertEquals(
-            List.of(
-                "abc__3__a__uuid4",
-                "abc__3__a__uuid5",
-                "abc__3__n__uuid3",
-                "abc__10__8__uuid8",
-                "abc__10__20__uuid1",
-                "abc__12__2__uuid2",
-                "pqr__1__1__uuid0"
-            ),
-            metadataFilenames
-        );
     }
 
     public void testInitException() throws IOException {
-        when(remoteMetadataDirectory.listFilesByPrefix(RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX)).thenThrow(
+        when(remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX, 1)).thenThrow(
             new IOException("Error")
         );
 
@@ -248,29 +233,42 @@ private ByteArrayIndexInput createMetadataFileBytes(Map<String, String> segmentF
     }
 
     private Map<String, Map<String, String>> populateMetadata() throws IOException {
-        List<String> metadataFiles = List.of("metadata__1__5__abc", "metadata__1__6__pqr", "metadata__2__1__zxv");
-        when(remoteMetadataDirectory.listFilesByPrefix(RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX)).thenReturn(
-            metadataFiles
-        );
+        List<String> metadataFiles = new ArrayList<>();
+
+        metadataFiles.add(metadataFilename);
+        metadataFiles.add(metadataFilename2);
+        metadataFiles.add(metadataFilename3);
+
+        when(
+            remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
+                RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX,
+                1
+            )
+        ).thenReturn(List.of(metadataFilename));
+        when(
+            remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
+                RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX,
+                Integer.MAX_VALUE
+            )
+        ).thenReturn(metadataFiles);
 
         Map<String, Map<String, String>> metadataFilenameContentMapping = Map.of(
-            "metadata__1__5__abc",
+            metadataFilename,
             getDummyMetadata("_0", 1),
-            "metadata__1__6__pqr",
+            metadataFilename2,
             getDummyMetadata("_0", 1),
-            "metadata__2__1__zxv",
+            metadataFilename3,
             getDummyMetadata("_0", 1)
         );
 
-        when(remoteMetadataDirectory.openInput("metadata__1__5__abc", IOContext.DEFAULT)).thenReturn(
-            createMetadataFileBytes(metadataFilenameContentMapping.get("metadata__1__5__abc"), 1, 5)
+        when(remoteMetadataDirectory.openInput(metadataFilename, IOContext.DEFAULT)).thenAnswer(
+            I -> createMetadataFileBytes(metadataFilenameContentMapping.get(metadataFilename), 23, 12)
         );
-        when(remoteMetadataDirectory.openInput("metadata__1__6__pqr", IOContext.DEFAULT)).thenReturn(
-            createMetadataFileBytes(metadataFilenameContentMapping.get("metadata__1__6__pqr"), 1, 6)
+        when(remoteMetadataDirectory.openInput(metadataFilename2, IOContext.DEFAULT)).thenAnswer(
+            I -> createMetadataFileBytes(metadataFilenameContentMapping.get(metadataFilename2), 13, 12)
         );
-        when(remoteMetadataDirectory.openInput("metadata__2__1__zxv", IOContext.DEFAULT)).thenReturn(
-            createMetadataFileBytes(metadataFilenameContentMapping.get("metadata__2__1__zxv"), 1, 2),
-            createMetadataFileBytes(metadataFilenameContentMapping.get("metadata__2__1__zxv"), 1, 2)
+        when(remoteMetadataDirectory.openInput(metadataFilename3, IOContext.DEFAULT)).thenAnswer(
+            I -> createMetadataFileBytes(metadataFilenameContentMapping.get(metadataFilename3), 38, 10)
         );
 
         return metadataFilenameContentMapping;
@@ -279,9 +277,12 @@ private Map<String, Map<String, String>> populateMetadata() throws IOException {
     public void testInit() throws IOException {
         populateMetadata();
 
-        when(remoteMetadataDirectory.listFilesByPrefix(RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX)).thenReturn(
-            List.of("metadata__1__5__abc", "metadata__1__6__pqr", "metadata__2__1__zxv")
-        );
+        when(
+            remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
+                RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX,
+                1
+            )
+        ).thenReturn(List.of(metadataFilename));
 
         remoteSegmentStoreDirectory.init();
 
@@ -385,15 +386,15 @@ public void testOpenInputException() throws IOException {
     public void testAcquireLock() throws IOException {
         populateMetadata();
         remoteSegmentStoreDirectory.init();
-        String mdFile = "xyz";
         String acquirerId = "test-acquirer";
         long testPrimaryTerm = 1;
         long testGeneration = 5;
 
         List<String> metadataFiles = List.of("metadata__1__5__abc");
         when(
-            remoteMetadataDirectory.listFilesByPrefix(
-                RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilePrefixForCommit(testPrimaryTerm, testGeneration)
+            remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
+                RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilePrefixForCommit(testPrimaryTerm, testGeneration),
+                1
             )
         ).thenReturn(metadataFiles);
 
@@ -423,8 +424,9 @@ public void testReleaseLock() throws IOException {
 
         List<String> metadataFiles = List.of("metadata__1__5__abc");
         when(
-            remoteMetadataDirectory.listFilesByPrefix(
-                RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilePrefixForCommit(testPrimaryTerm, testGeneration)
+            remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
+                RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilePrefixForCommit(testPrimaryTerm, testGeneration),
+                1
             )
         ).thenReturn(metadataFiles);
 
@@ -440,8 +442,9 @@ public void testIsAcquired() throws IOException {
 
         List<String> metadataFiles = List.of("metadata__1__5__abc");
         when(
-            remoteMetadataDirectory.listFilesByPrefix(
-                RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilePrefixForCommit(testPrimaryTerm, testGeneration)
+            remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
+                RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilePrefixForCommit(testPrimaryTerm, testGeneration),
+                1
             )
         ).thenReturn(metadataFiles);
 
@@ -457,8 +460,9 @@ public void testIsAcquiredException() throws IOException {
 
         List<String> metadataFiles = new ArrayList<>();
         when(
-            remoteMetadataDirectory.listFilesByPrefix(
-                RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilePrefixForCommit(testPrimaryTerm, testGeneration)
+            remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
+                RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilePrefixForCommit(testPrimaryTerm, testGeneration),
+                1
             )
         ).thenReturn(metadataFiles);
 
@@ -468,14 +472,10 @@ public void testIsAcquiredException() throws IOException {
     public void testGetMetadataFileForCommit() throws IOException {
         long testPrimaryTerm = 2;
         long testGeneration = 3;
-        List<String> metadataFiles = List.of(
-            "metadata__1__5__abc",
-            "metadata__" + testPrimaryTerm + "__" + testGeneration + "__pqr",
-            "metadata__2__1__zxv"
-        );
         when(
-            remoteMetadataDirectory.listFilesByPrefix(
-                RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilePrefixForCommit(testPrimaryTerm, testGeneration)
+            remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
+                RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilePrefixForCommit(testPrimaryTerm, testGeneration),
+                1
             )
         ).thenReturn(List.of("metadata__" + testPrimaryTerm + "__" + testGeneration + "__pqr"));
 
@@ -484,33 +484,6 @@ public void testGetMetadataFileForCommit() throws IOException {
 
     }
 
-    public void testGetSegmentsUploadedToRemoteStore() throws IOException {
-        long testPrimaryTerm = 1;
-        long testGeneration = 5;
-
-        List<String> metadataFiles = List.of("metadata__1__5__abc");
-        when(
-            remoteMetadataDirectory.listFilesByPrefix(
-                RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilePrefixForCommit(testPrimaryTerm, testGeneration)
-            )
-        ).thenReturn(metadataFiles);
-
-        Map<String, Map<String, String>> metadataFilenameContentMapping = Map.of(
-            "metadata__1__5__abc",
-            getDummyMetadata("_0", 5),
-            "metadata__1__6__pqr",
-            getDummyMetadata("_0", 6),
-            "metadata__2__1__zxv",
-            getDummyMetadata("_0", 1)
-        );
-
-        when(remoteMetadataDirectory.openInput("metadata__1__5__abc", IOContext.DEFAULT)).thenReturn(
-            createMetadataFileBytes(metadataFilenameContentMapping.get("metadata__1__5__abc"), 1, 5)
-        );
-
-        assert (remoteSegmentStoreDirectory.getSegmentsUploadedToRemoteStore(testPrimaryTerm, testGeneration).containsKey("segments_5"));
-    }
-
     public void testCopyFrom() throws IOException {
         String filename = "_100.si";
         populateMetadata();
@@ -542,46 +515,20 @@ public void testCopyFromException() throws IOException {
         storeDirectory.close();
     }
 
-    public void testCopyFromOverride() throws IOException {
-        String filename = "_100.si";
-        populateMetadata();
-        remoteSegmentStoreDirectory.init();
-
-        Directory storeDirectory = LuceneTestCase.newDirectory();
-        IndexOutput indexOutput = storeDirectory.createOutput(filename, IOContext.DEFAULT);
-        indexOutput.writeString("Hello World!");
-        CodecUtil.writeFooter(indexOutput);
-        indexOutput.close();
-        storeDirectory.sync(List.of(filename));
-
-        assertFalse(remoteSegmentStoreDirectory.getSegmentsUploadedToRemoteStore().containsKey(filename));
-        remoteSegmentStoreDirectory.copyFrom(storeDirectory, filename, filename, IOContext.DEFAULT, true);
-        RemoteSegmentStoreDirectory.UploadedSegmentMetadata uploadedSegmentMetadata = remoteSegmentStoreDirectory
-            .getSegmentsUploadedToRemoteStore()
-            .get(filename);
-        assertNotNull(uploadedSegmentMetadata);
-        remoteSegmentStoreDirectory.copyFrom(storeDirectory, filename, filename, IOContext.DEFAULT, true);
-        assertEquals(
-            uploadedSegmentMetadata.toString(),
-            remoteSegmentStoreDirectory.getSegmentsUploadedToRemoteStore().get(filename).toString()
-        );
-
-        storeDirectory.close();
-    }
-
     public void testContainsFile() throws IOException {
-        List<String> metadataFiles = List.of("metadata__1__5__abc");
-        when(remoteMetadataDirectory.listFilesByPrefix(RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX)).thenReturn(
-            metadataFiles
-        );
+        List<String> metadataFiles = List.of(metadataFilename);
+        when(
+            remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
+                RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX,
+                1
+            )
+        ).thenReturn(metadataFiles);
 
         Map<String, String> metadata = new HashMap<>();
         metadata.put("_0.cfe", "_0.cfe::_0.cfe__" + UUIDs.base64UUID() + "::1234::512");
         metadata.put("_0.cfs", "_0.cfs::_0.cfs__" + UUIDs.base64UUID() + "::2345::1024");
 
-        when(remoteMetadataDirectory.openInput("metadata__1__5__abc", IOContext.DEFAULT)).thenReturn(
-            createMetadataFileBytes(metadata, 1, 5)
-        );
+        when(remoteMetadataDirectory.openInput(metadataFilename, IOContext.DEFAULT)).thenReturn(createMetadataFileBytes(metadata, 1, 5));
 
         remoteSegmentStoreDirectory.init();
 
@@ -611,7 +558,7 @@ public void testUploadMetadataEmpty() throws IOException {
         Collection<String> segmentFiles = List.of("s1", "s2", "s3");
         assertThrows(
             NoSuchFileException.class,
-            () -> remoteSegmentStoreDirectory.uploadMetadata(segmentFiles, segmentInfos, storeDirectory, 12L)
+            () -> remoteSegmentStoreDirectory.uploadMetadata(segmentFiles, segmentInfos, storeDirectory, 12L, 34L)
         );
     }
 
@@ -623,16 +570,19 @@ public void testUploadMetadataNonEmpty() throws IOException {
         BytesStreamOutput output = new BytesStreamOutput();
         IndexOutput indexOutput = new OutputStreamIndexOutput("segment metadata", "metadata output stream", output, 4096);
 
-        long generation = segmentInfos.getGeneration();
-        when(storeDirectory.createOutput(startsWith("metadata__12__" + generation), eq(IOContext.DEFAULT))).thenReturn(indexOutput);
+        String generation = RemoteStoreUtils.invertLong(segmentInfos.getGeneration());
+        String primaryTerm = RemoteStoreUtils.invertLong(12);
+        when(storeDirectory.createOutput(startsWith("metadata__" + primaryTerm + "__" + generation), eq(IOContext.DEFAULT))).thenReturn(
+            indexOutput
+        );
 
         Collection<String> segmentFiles = List.of("_0.si", "_0.cfe", "_0.cfs", "segments_1");
-        remoteSegmentStoreDirectory.uploadMetadata(segmentFiles, segmentInfos, storeDirectory, 12L);
+        remoteSegmentStoreDirectory.uploadMetadata(segmentFiles, segmentInfos, storeDirectory, 12L, 34L);
 
         verify(remoteMetadataDirectory).copyFrom(
             eq(storeDirectory),
-            startsWith("metadata__12__" + generation),
-            startsWith("metadata__12__" + generation),
+            startsWith("metadata__" + primaryTerm + "__" + generation),
+            startsWith("metadata__" + primaryTerm + "__" + generation),
             eq(IOContext.DEFAULT)
         );
 
@@ -655,10 +605,13 @@ public void testUploadMetadataNonEmpty() throws IOException {
     }
 
     public void testNoMetadataHeaderCorruptIndexException() throws IOException {
-        List<String> metadataFiles = List.of("metadata__1__5__abc");
-        when(remoteMetadataDirectory.listFilesByPrefix(RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX)).thenReturn(
-            metadataFiles
-        );
+        List<String> metadataFiles = List.of(metadataFilename);
+        when(
+            remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
+                RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX,
+                1
+            )
+        ).thenReturn(metadataFiles);
 
         Map<String, String> metadata = new HashMap<>();
         metadata.put("_0.cfe", "_0.cfe::_0.cfe__" + UUIDs.base64UUID() + "::1234");
@@ -669,16 +622,19 @@ public void testNoMetadataHeaderCorruptIndexException() throws IOException {
         indexOutput.writeMapOfStrings(metadata);
         indexOutput.close();
         ByteArrayIndexInput byteArrayIndexInput = new ByteArrayIndexInput("segment metadata", BytesReference.toBytes(output.bytes()));
-        when(remoteMetadataDirectory.openInput("metadata__1__5__abc", IOContext.DEFAULT)).thenReturn(byteArrayIndexInput);
+        when(remoteMetadataDirectory.openInput(metadataFilename, IOContext.DEFAULT)).thenReturn(byteArrayIndexInput);
 
         assertThrows(CorruptIndexException.class, () -> remoteSegmentStoreDirectory.init());
     }
 
     public void testInvalidCodecHeaderCorruptIndexException() throws IOException {
-        List<String> metadataFiles = List.of("metadata__1__5__abc");
-        when(remoteMetadataDirectory.listFilesByPrefix(RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX)).thenReturn(
-            metadataFiles
-        );
+        List<String> metadataFiles = List.of(metadataFilename);
+        when(
+            remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
+                RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX,
+                1
+            )
+        ).thenReturn(metadataFiles);
 
         Map<String, String> metadata = new HashMap<>();
         metadata.put("_0.cfe", "_0.cfe::_0.cfe__" + UUIDs.base64UUID() + "::1234");
@@ -691,16 +647,19 @@ public void testInvalidCodecHeaderCorruptIndexException() throws IOException {
         CodecUtil.writeFooter(indexOutput);
         indexOutput.close();
         ByteArrayIndexInput byteArrayIndexInput = new ByteArrayIndexInput("segment metadata", BytesReference.toBytes(output.bytes()));
-        when(remoteMetadataDirectory.openInput("metadata__1__5__abc", IOContext.DEFAULT)).thenReturn(byteArrayIndexInput);
+        when(remoteMetadataDirectory.openInput(metadataFilename, IOContext.DEFAULT)).thenReturn(byteArrayIndexInput);
 
         assertThrows(CorruptIndexException.class, () -> remoteSegmentStoreDirectory.init());
     }
 
     public void testHeaderMinVersionCorruptIndexException() throws IOException {
-        List<String> metadataFiles = List.of("metadata__1__5__abc");
-        when(remoteMetadataDirectory.listFilesByPrefix(RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX)).thenReturn(
-            metadataFiles
-        );
+        List<String> metadataFiles = List.of(metadataFilename);
+        when(
+            remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
+                RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX,
+                1
+            )
+        ).thenReturn(metadataFiles);
 
         Map<String, String> metadata = new HashMap<>();
         metadata.put("_0.cfe", "_0.cfe::_0.cfe__" + UUIDs.base64UUID() + "::1234");
@@ -713,16 +672,19 @@ public void testHeaderMinVersionCorruptIndexException() throws IOException {
         CodecUtil.writeFooter(indexOutput);
         indexOutput.close();
         ByteArrayIndexInput byteArrayIndexInput = new ByteArrayIndexInput("segment metadata", BytesReference.toBytes(output.bytes()));
-        when(remoteMetadataDirectory.openInput("metadata__1__5__abc", IOContext.DEFAULT)).thenReturn(byteArrayIndexInput);
+        when(remoteMetadataDirectory.openInput(metadataFilename, IOContext.DEFAULT)).thenReturn(byteArrayIndexInput);
 
         assertThrows(IndexFormatTooOldException.class, () -> remoteSegmentStoreDirectory.init());
     }
 
     public void testHeaderMaxVersionCorruptIndexException() throws IOException {
-        List<String> metadataFiles = List.of("metadata__1__5__abc");
-        when(remoteMetadataDirectory.listFilesByPrefix(RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX)).thenReturn(
-            metadataFiles
-        );
+        List<String> metadataFiles = List.of(metadataFilename);
+        when(
+            remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
+                RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX,
+                1
+            )
+        ).thenReturn(metadataFiles);
 
         Map<String, String> metadata = new HashMap<>();
         metadata.put("_0.cfe", "_0.cfe::_0.cfe__" + UUIDs.base64UUID() + "::1234");
@@ -735,16 +697,19 @@ public void testHeaderMaxVersionCorruptIndexException() throws IOException {
         CodecUtil.writeFooter(indexOutput);
         indexOutput.close();
         ByteArrayIndexInput byteArrayIndexInput = new ByteArrayIndexInput("segment metadata", BytesReference.toBytes(output.bytes()));
-        when(remoteMetadataDirectory.openInput("metadata__1__5__abc", IOContext.DEFAULT)).thenReturn(byteArrayIndexInput);
+        when(remoteMetadataDirectory.openInput(metadataFilename, IOContext.DEFAULT)).thenReturn(byteArrayIndexInput);
 
         assertThrows(IndexFormatTooNewException.class, () -> remoteSegmentStoreDirectory.init());
     }
 
     public void testIncorrectChecksumCorruptIndexException() throws IOException {
-        List<String> metadataFiles = List.of("metadata__1__5__abc");
-        when(remoteMetadataDirectory.listFilesByPrefix(RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX)).thenReturn(
-            metadataFiles
-        );
+        List<String> metadataFiles = List.of(metadataFilename);
+        when(
+            remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
+                RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX,
+                1
+            )
+        ).thenReturn(metadataFiles);
 
         Map<String, String> metadata = new HashMap<>();
         metadata.put("_0.cfe", "_0.cfe::_0.cfe__" + UUIDs.base64UUID() + "::1234::512");
@@ -761,50 +726,88 @@ public void testIncorrectChecksumCorruptIndexException() throws IOException {
         indexOutputSpy.close();
 
         ByteArrayIndexInput byteArrayIndexInput = new ByteArrayIndexInput("segment metadata", BytesReference.toBytes(output.bytes()));
-        when(remoteMetadataDirectory.openInput("metadata__1__5__abc", IOContext.DEFAULT)).thenReturn(byteArrayIndexInput);
+        when(remoteMetadataDirectory.openInput(metadataFilename, IOContext.DEFAULT)).thenReturn(byteArrayIndexInput);
 
         assertThrows(CorruptIndexException.class, () -> remoteSegmentStoreDirectory.init());
     }
 
-    public void testDeleteStaleCommitsException() throws IOException {
-        when(remoteMetadataDirectory.listFilesByPrefix(RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX)).thenThrow(
-            new IOException("Error reading")
-        );
+    public void testDeleteStaleCommitsException() throws Exception {
+        populateMetadata();
+        when(
+            remoteMetadataDirectory.listFilesByPrefixInLexicographicOrder(
+                RemoteSegmentStoreDirectory.MetadataFilenameUtils.METADATA_PREFIX,
+                Integer.MAX_VALUE
+            )
+        ).thenThrow(new IOException("Error reading"));
+
+        // popluateMetadata() adds stub to return 3 metadata files
+        // We are passing lastNMetadataFilesToKeep=2 here to validate that in case of exception deleteFile is not
+        // invoked
+        remoteSegmentStoreDirectory.deleteStaleSegmentsAsync(2);
+
+        assertBusy(() -> assertThat(remoteSegmentStoreDirectory.canDeleteStaleCommits.get(), is(true)));
+        verify(remoteMetadataDirectory, times(0)).deleteFile(any(String.class));
+    }
+
+    public void testDeleteStaleCommitsExceptionWhileScheduling() throws Exception {
+        populateMetadata();
+        doThrow(new IllegalArgumentException()).when(threadPool).executor(any(String.class));
+
+        // popluateMetadata() adds stub to return 3 metadata files
+        // We are passing lastNMetadataFilesToKeep=2 here to validate that in case of exception deleteFile is not
+        // invoked
+        remoteSegmentStoreDirectory.deleteStaleSegmentsAsync(2);
 
-        assertThrows(IOException.class, () -> remoteSegmentStoreDirectory.deleteStaleSegments(5));
+        assertBusy(() -> assertThat(remoteSegmentStoreDirectory.canDeleteStaleCommits.get(), is(true)));
+        verify(remoteMetadataDirectory, times(0)).deleteFile(any(String.class));
     }
 
-    public void testDeleteStaleCommitsWithinThreshold() throws IOException {
+    public void testDeleteStaleCommitsWithDeletionAlreadyInProgress() throws Exception {
+        populateMetadata();
+        remoteSegmentStoreDirectory.canDeleteStaleCommits.set(false);
+
+        // popluateMetadata() adds stub to return 3 metadata files
+        // We are passing lastNMetadataFilesToKeep=2 here to validate that in case of exception deleteFile is not
+        // invoked
+        remoteSegmentStoreDirectory.deleteStaleSegmentsAsync(2);
+
+        assertBusy(() -> assertThat(remoteSegmentStoreDirectory.canDeleteStaleCommits.get(), is(false)));
+        verify(remoteMetadataDirectory, times(0)).deleteFile(any(String.class));
+    }
+
+    public void testDeleteStaleCommitsWithinThreshold() throws Exception {
         populateMetadata();
 
         // popluateMetadata() adds stub to return 3 metadata files
         // We are passing lastNMetadataFilesToKeep=5 here so that none of the metadata files will be deleted
-        remoteSegmentStoreDirectory.deleteStaleSegments(5);
+        remoteSegmentStoreDirectory.deleteStaleSegmentsAsync(5);
 
+        assertBusy(() -> assertThat(remoteSegmentStoreDirectory.canDeleteStaleCommits.get(), is(true)));
         verify(remoteMetadataDirectory, times(0)).openInput(any(String.class), eq(IOContext.DEFAULT));
     }
 
-    public void testDeleteStaleCommitsActualDelete() throws IOException {
+    public void testDeleteStaleCommitsActualDelete() throws Exception {
         Map<String, Map<String, String>> metadataFilenameContentMapping = populateMetadata();
         remoteSegmentStoreDirectory.init();
 
         // popluateMetadata() adds stub to return 3 metadata files
         // We are passing lastNMetadataFilesToKeep=2 here so that oldest 1 metadata file will be deleted
-        remoteSegmentStoreDirectory.deleteStaleSegments(2);
+        remoteSegmentStoreDirectory.deleteStaleSegmentsAsync(2);
 
-        for (String metadata : metadataFilenameContentMapping.get("metadata__1__5__abc").values()) {
+        for (String metadata : metadataFilenameContentMapping.get(metadataFilename3).values()) {
             String uploadedFilename = metadata.split(RemoteSegmentStoreDirectory.UploadedSegmentMetadata.SEPARATOR)[1];
             verify(remoteDataDirectory).deleteFile(uploadedFilename);
         }
         ;
-        verify(remoteMetadataDirectory).deleteFile("metadata__1__5__abc");
+        assertBusy(() -> assertThat(remoteSegmentStoreDirectory.canDeleteStaleCommits.get(), is(true)));
+        verify(remoteMetadataDirectory).deleteFile(metadataFilename3);
     }
 
-    public void testDeleteStaleCommitsActualDeleteIOException() throws IOException {
+    public void testDeleteStaleCommitsActualDeleteIOException() throws Exception {
         Map<String, Map<String, String>> metadataFilenameContentMapping = populateMetadata();
         remoteSegmentStoreDirectory.init();
 
-        String segmentFileWithException = metadataFilenameContentMapping.get("metadata__1__5__abc")
+        String segmentFileWithException = metadataFilenameContentMapping.get(metadataFilename3)
             .values()
             .stream()
             .findAny()
@@ -813,21 +816,21 @@ public void testDeleteStaleCommitsActualDeleteIOException() throws IOException {
         doThrow(new IOException("Error")).when(remoteDataDirectory).deleteFile(segmentFileWithException);
         // popluateMetadata() adds stub to return 3 metadata files
         // We are passing lastNMetadataFilesToKeep=2 here so that oldest 1 metadata file will be deleted
-        remoteSegmentStoreDirectory.deleteStaleSegments(2);
+        remoteSegmentStoreDirectory.deleteStaleSegmentsAsync(2);
 
-        for (String metadata : metadataFilenameContentMapping.get("metadata__1__5__abc").values()) {
+        for (String metadata : metadataFilenameContentMapping.get(metadataFilename3).values()) {
             String uploadedFilename = metadata.split(RemoteSegmentStoreDirectory.UploadedSegmentMetadata.SEPARATOR)[1];
             verify(remoteDataDirectory).deleteFile(uploadedFilename);
         }
-        ;
-        verify(remoteMetadataDirectory, times(0)).deleteFile("metadata__1__5__abc");
+        assertBusy(() -> assertThat(remoteSegmentStoreDirectory.canDeleteStaleCommits.get(), is(true)));
+        verify(remoteMetadataDirectory, times(0)).deleteFile(metadataFilename3);
     }
 
-    public void testDeleteStaleCommitsActualDeleteNoSuchFileException() throws IOException {
+    public void testDeleteStaleCommitsActualDeleteNoSuchFileException() throws Exception {
         Map<String, Map<String, String>> metadataFilenameContentMapping = populateMetadata();
         remoteSegmentStoreDirectory.init();
 
-        String segmentFileWithException = metadataFilenameContentMapping.get("metadata__1__5__abc")
+        String segmentFileWithException = metadataFilenameContentMapping.get(metadataFilename)
             .values()
             .stream()
             .findAny()
@@ -836,14 +839,14 @@ public void testDeleteStaleCommitsActualDeleteNoSuchFileException() throws IOExc
         doThrow(new NoSuchFileException(segmentFileWithException)).when(remoteDataDirectory).deleteFile(segmentFileWithException);
         // popluateMetadata() adds stub to return 3 metadata files
         // We are passing lastNMetadataFilesToKeep=2 here so that oldest 1 metadata file will be deleted
-        remoteSegmentStoreDirectory.deleteStaleSegments(2);
+        remoteSegmentStoreDirectory.deleteStaleSegmentsAsync(2);
 
-        for (String metadata : metadataFilenameContentMapping.get("metadata__1__5__abc").values()) {
+        for (String metadata : metadataFilenameContentMapping.get(metadataFilename3).values()) {
             String uploadedFilename = metadata.split(RemoteSegmentStoreDirectory.UploadedSegmentMetadata.SEPARATOR)[1];
             verify(remoteDataDirectory).deleteFile(uploadedFilename);
         }
-        ;
-        verify(remoteMetadataDirectory).deleteFile("metadata__1__5__abc");
+        assertBusy(() -> assertThat(remoteSegmentStoreDirectory.canDeleteStaleCommits.get(), is(true)));
+        verify(remoteMetadataDirectory).deleteFile(metadataFilename3);
     }
 
     public void testSegmentMetadataCurrentVersion() {
@@ -858,6 +861,20 @@ public void testSegmentMetadataCurrentVersion() {
         assertEquals(RemoteSegmentMetadata.CURRENT_VERSION, 1);
     }
 
+    public void testMetadataFileNameOrder() {
+        String file1 = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(15, 21, 23, 1, 1);
+        String file2 = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(15, 38, 38, 1, 1);
+        String file3 = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(18, 12, 26, 1, 1);
+        String file4 = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(15, 38, 32, 10, 1);
+        String file5 = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(15, 38, 32, 1, 1);
+        String file6 = RemoteSegmentStoreDirectory.MetadataFilenameUtils.getMetadataFilename(15, 38, 32, 5, 1);
+
+        List<String> actualList = new ArrayList<>(List.of(file1, file2, file3, file4, file5, file6));
+        actualList.sort(String::compareTo);
+
+        assertEquals(List.of(file3, file2, file4, file6, file5, file1), actualList);
+    }
+
     private static class WrapperIndexOutput extends IndexOutput {
         public IndexOutput indexOutput;
 
diff --git a/server/src/test/java/org/opensearch/index/store/lockmanager/FileLockInfoTests.java b/server/src/test/java/org/opensearch/index/store/lockmanager/FileLockInfoTests.java
index 95af53cb6e5ec..f3a2f1859923e 100644
--- a/server/src/test/java/org/opensearch/index/store/lockmanager/FileLockInfoTests.java
+++ b/server/src/test/java/org/opensearch/index/store/lockmanager/FileLockInfoTests.java
@@ -10,7 +10,7 @@
 
 import org.opensearch.test.OpenSearchTestCase;
 
-import java.util.List;
+import java.nio.file.NoSuchFileException;
 
 public class FileLockInfoTests extends OpenSearchTestCase {
     String testMetadata = "testMetadata";
@@ -41,16 +41,13 @@ public void testGetLockPrefixFailureCase() {
         assertThrows(IllegalArgumentException.class, fileLockInfo::getLockPrefix);
     }
 
-    public void testGetLocksForAcquirer() {
+    public void testGetLocksForAcquirer() throws NoSuchFileException {
         String[] locks = new String[] {
             FileLockInfo.LockFileUtils.generateLockName(testMetadata, testAcquirerId),
             FileLockInfo.LockFileUtils.generateLockName(testMetadata, "acquirerId2") };
         FileLockInfo fileLockInfo = FileLockInfo.getLockInfoBuilder().withAcquirerId(testAcquirerId).build();
 
-        assertEquals(
-            fileLockInfo.getLocksForAcquirer(locks),
-            List.of(FileLockInfo.LockFileUtils.generateLockName(testMetadata, testAcquirerId))
-        );
+        assertEquals(fileLockInfo.getLockForAcquirer(locks), FileLockInfo.LockFileUtils.generateLockName(testMetadata, testAcquirerId));
     }
 
 }
diff --git a/server/src/test/java/org/opensearch/repositories/RepositoriesServiceTests.java b/server/src/test/java/org/opensearch/repositories/RepositoriesServiceTests.java
index f5295bead19a4..edf5b6c84bc54 100644
--- a/server/src/test/java/org/opensearch/repositories/RepositoriesServiceTests.java
+++ b/server/src/test/java/org/opensearch/repositories/RepositoriesServiceTests.java
@@ -60,6 +60,7 @@
 import org.opensearch.index.snapshots.IndexShardSnapshotStatus;
 import org.opensearch.index.snapshots.blobstore.RemoteStoreShardShallowCopySnapshot;
 import org.opensearch.index.store.Store;
+import org.opensearch.index.store.lockmanager.RemoteStoreLockManagerFactory;
 import org.opensearch.indices.recovery.RecoverySettings;
 import org.opensearch.indices.recovery.RecoveryState;
 import org.opensearch.repositories.blobstore.MeteredBlobStoreRepository;
@@ -378,6 +379,18 @@ public void cloneShardSnapshot(
 
         }
 
+        @Override
+        public void cloneRemoteStoreIndexShardSnapshot(
+            SnapshotId source,
+            SnapshotId target,
+            RepositoryShardId shardId,
+            String shardGeneration,
+            RemoteStoreLockManagerFactory remoteStoreLockManagerFactory,
+            ActionListener<String> listener
+        ) {
+
+        }
+
         @Override
         public Lifecycle.State lifecycleState() {
             return null;
diff --git a/server/src/test/java/org/opensearch/rest/NamedRouteTests.java b/server/src/test/java/org/opensearch/rest/NamedRouteTests.java
index d489321ea5dc6..cf3e2b5b858bf 100644
--- a/server/src/test/java/org/opensearch/rest/NamedRouteTests.java
+++ b/server/src/test/java/org/opensearch/rest/NamedRouteTests.java
@@ -11,22 +11,17 @@
 import org.opensearch.OpenSearchException;
 import org.opensearch.test.OpenSearchTestCase;
 
+import java.util.Set;
+import java.util.function.Function;
+
 import static org.opensearch.rest.NamedRoute.MAX_LENGTH_OF_ACTION_NAME;
+import static org.opensearch.rest.RestRequest.Method.GET;
 
 public class NamedRouteTests extends OpenSearchTestCase {
 
-    public void testNamedRouteWithNullName() {
-        try {
-            NamedRoute r = new NamedRoute(RestRequest.Method.GET, "foo/bar", null);
-            fail("Expected NamedRoute to throw exception on null name provided");
-        } catch (OpenSearchException e) {
-            assertTrue(e.getMessage().contains("Invalid route name specified"));
-        }
-    }
-
     public void testNamedRouteWithEmptyName() {
         try {
-            NamedRoute r = new NamedRoute(RestRequest.Method.GET, "foo/bar", "");
+            NamedRoute r = new NamedRoute.Builder().method(GET).path("foo/bar").uniqueName("").build();
             fail("Expected NamedRoute to throw exception on empty name provided");
         } catch (OpenSearchException e) {
             assertTrue(e.getMessage().contains("Invalid route name specified"));
@@ -35,7 +30,7 @@ public void testNamedRouteWithEmptyName() {
 
     public void testNamedRouteWithNameContainingSpace() {
         try {
-            NamedRoute r = new NamedRoute(RestRequest.Method.GET, "foo/bar", "foo bar");
+            NamedRoute r = new NamedRoute.Builder().method(GET).path("foo/bar").uniqueName("foo bar").build();
             fail("Expected NamedRoute to throw exception on name containing space name provided");
         } catch (OpenSearchException e) {
             assertTrue(e.getMessage().contains("Invalid route name specified"));
@@ -44,7 +39,7 @@ public void testNamedRouteWithNameContainingSpace() {
 
     public void testNamedRouteWithNameContainingInvalidCharacters() {
         try {
-            NamedRoute r = new NamedRoute(RestRequest.Method.GET, "foo/bar", "foo@bar!");
+            NamedRoute r = new NamedRoute.Builder().method(GET).path("foo/bar").uniqueName("foo@bar!").build();
             fail("Expected NamedRoute to throw exception on name containing invalid characters name provided");
         } catch (OpenSearchException e) {
             assertTrue(e.getMessage().contains("Invalid route name specified"));
@@ -54,7 +49,7 @@ public void testNamedRouteWithNameContainingInvalidCharacters() {
     public void testNamedRouteWithNameOverMaximumLength() {
         try {
             String repeated = new String(new char[MAX_LENGTH_OF_ACTION_NAME + 1]).replace("\0", "x");
-            NamedRoute r = new NamedRoute(RestRequest.Method.GET, "foo/bar", repeated);
+            NamedRoute r = new NamedRoute.Builder().method(GET).path("foo/bar").uniqueName(repeated).build();
             fail("Expected NamedRoute to throw exception on name over maximum length supplied");
         } catch (OpenSearchException e) {
             assertTrue(e.getMessage().contains("Invalid route name specified"));
@@ -63,7 +58,7 @@ public void testNamedRouteWithNameOverMaximumLength() {
 
     public void testNamedRouteWithValidActionName() {
         try {
-            NamedRoute r = new NamedRoute(RestRequest.Method.GET, "foo/bar", "foo:bar");
+            NamedRoute r = new NamedRoute.Builder().method(GET).path("foo/bar").uniqueName("foo:bar").build();
         } catch (OpenSearchException e) {
             fail("Did not expect NamedRoute to throw exception on valid action name");
         }
@@ -71,7 +66,7 @@ public void testNamedRouteWithValidActionName() {
 
     public void testNamedRouteWithValidActionNameWithForwardSlash() {
         try {
-            NamedRoute r = new NamedRoute(RestRequest.Method.GET, "foo/bar", "foo:bar/baz");
+            NamedRoute r = new NamedRoute.Builder().method(GET).path("foo/bar").uniqueName("foo:bar:baz").build();
         } catch (OpenSearchException e) {
             fail("Did not expect NamedRoute to throw exception on valid action name");
         }
@@ -79,7 +74,7 @@ public void testNamedRouteWithValidActionNameWithForwardSlash() {
 
     public void testNamedRouteWithValidActionNameWithWildcard() {
         try {
-            NamedRoute r = new NamedRoute(RestRequest.Method.GET, "foo/bar", "foo:bar/*");
+            NamedRoute r = new NamedRoute.Builder().method(GET).path("foo/bar").uniqueName("foo:bar/*").build();
         } catch (OpenSearchException e) {
             fail("Did not expect NamedRoute to throw exception on valid action name");
         }
@@ -87,9 +82,82 @@ public void testNamedRouteWithValidActionNameWithWildcard() {
 
     public void testNamedRouteWithValidActionNameWithUnderscore() {
         try {
-            NamedRoute r = new NamedRoute(RestRequest.Method.GET, "foo/bar", "foo:bar_baz");
+            NamedRoute r = new NamedRoute.Builder().method(GET).path("foo/bar").uniqueName("foo:bar_baz").build();
         } catch (OpenSearchException e) {
             fail("Did not expect NamedRoute to throw exception on valid action name");
         }
     }
+
+    public void testNamedRouteWithNullLegacyActionNames() {
+        try {
+            NamedRoute r = new NamedRoute.Builder().method(GET).path("foo/bar").uniqueName("foo:bar").legacyActionNames(null).build();
+            assertTrue(r.actionNames().isEmpty());
+        } catch (OpenSearchException e) {
+            fail("Did not expect NamedRoute to pass with an invalid legacy action name");
+        }
+    }
+
+    public void testNamedRouteWithInvalidLegacyActionNames() {
+        try {
+            NamedRoute r = new NamedRoute.Builder().method(GET)
+                .path("foo/bar")
+                .uniqueName("foo:bar")
+                .legacyActionNames(Set.of("foo:bar-legacy"))
+                .build();
+            fail("Did not expect NamedRoute to pass with an invalid legacy action name");
+        } catch (OpenSearchException e) {
+            assertTrue(e.getMessage().contains("Invalid action name [foo:bar-legacy]. It must start with one of:"));
+        }
+    }
+
+    public void testNamedRouteWithHandler() {
+        Function<RestRequest, RestResponse> fooHandler = restRequest -> null;
+        try {
+            NamedRoute r = new NamedRoute.Builder().method(GET).path("foo/bar").uniqueName("foo:bar_baz").handler(fooHandler).build();
+            assertEquals(r.handler(), fooHandler);
+        } catch (OpenSearchException e) {
+            fail("Did not expect NamedRoute to throw exception");
+        }
+    }
+
+    public void testNamedRouteNullChecks() {
+        try {
+            NamedRoute r = new NamedRoute.Builder().method(null).path("foo/bar").uniqueName("foo:bar_baz").build();
+            fail("Expected NamedRoute to throw exception as method should not be null");
+        } catch (NullPointerException e) {
+            assertEquals("REST method must not be null.", e.getMessage());
+        }
+
+        try {
+            NamedRoute r = new NamedRoute.Builder().method(GET).path(null).uniqueName("foo:bar_baz").build();
+            fail("Expected NamedRoute to throw exception as path should not be null");
+        } catch (NullPointerException e) {
+            assertEquals("REST path must not be null.", e.getMessage());
+        }
+
+        try {
+            NamedRoute r = new NamedRoute.Builder().method(GET).path("foo/bar").uniqueName(null).build();
+            fail("Expected NamedRoute to throw exception as route name should not be null");
+        } catch (NullPointerException e) {
+            assertEquals("REST route name must not be null.", e.getMessage());
+        }
+
+        try {
+            NamedRoute r = new NamedRoute.Builder().method(GET).path("foo/bar").uniqueName("foo:bar_baz").handler(null).build();
+            fail("Expected NamedRoute to throw exception as handler should not be null");
+        } catch (NullPointerException e) {
+            assertEquals("Route handler must not be null.", e.getMessage());
+        }
+    }
+
+    public void testNamedRouteEmptyBuild() {
+        try {
+            NamedRoute r = new NamedRoute.Builder().build();
+            fail("Expected NamedRoute to throw exception as fields should not be null");
+        } catch (IllegalStateException e) {
+            assertEquals("REST method, path and uniqueName are required.", e.getMessage());
+        }
+
+    }
+
 }
diff --git a/server/src/test/java/org/opensearch/search/SearchServiceTests.java b/server/src/test/java/org/opensearch/search/SearchServiceTests.java
index 8f8789a3a0323..74ef289c4b75f 100644
--- a/server/src/test/java/org/opensearch/search/SearchServiceTests.java
+++ b/server/src/test/java/org/opensearch/search/SearchServiceTests.java
@@ -1748,4 +1748,21 @@ public void testCanMatchSearchAfterDescEqualMin() throws IOException {
         primarySort.order(SortOrder.DESC);
         assertEquals(SearchService.canMatchSearchAfter(searchAfter, minMax, primarySort), true);
     }
+
+    /**
+     * Test canMatchSearchAfter with missing value, even if min/max is out of range
+     * Min = 0L, Max = 9L, search_after = -1L
+     * Expected result is canMatch = true
+     */
+    public void testCanMatchSearchAfterWithMissing() throws IOException {
+        FieldDoc searchAfter = new FieldDoc(0, 0, new Long[] { -1L });
+        MinAndMax<?> minMax = new MinAndMax<Long>(0L, 9L);
+        FieldSortBuilder primarySort = new FieldSortBuilder("test");
+        primarySort.order(SortOrder.DESC);
+        // Should be false without missing values
+        assertEquals(SearchService.canMatchSearchAfter(searchAfter, minMax, primarySort), false);
+        primarySort.missing("_last");
+        // Should be true with missing values
+        assertEquals(SearchService.canMatchSearchAfter(searchAfter, minMax, primarySort), true);
+    }
 }
diff --git a/server/src/test/java/org/opensearch/search/pipeline/SearchPipelineServiceTests.java b/server/src/test/java/org/opensearch/search/pipeline/SearchPipelineServiceTests.java
index 2ac0b2136ddd9..84f39e4bdab42 100644
--- a/server/src/test/java/org/opensearch/search/pipeline/SearchPipelineServiceTests.java
+++ b/server/src/test/java/org/opensearch/search/pipeline/SearchPipelineServiceTests.java
@@ -77,19 +77,17 @@ public class SearchPipelineServiceTests extends OpenSearchTestCase {
 
     private static final SearchPipelinePlugin DUMMY_PLUGIN = new SearchPipelinePlugin() {
         @Override
-        public Map<String, Processor.Factory<SearchRequestProcessor>> getRequestProcessors(Processor.Parameters parameters) {
-            return Map.of("foo", (factories, tag, description, config) -> null);
+        public Map<String, Processor.Factory<SearchRequestProcessor>> getRequestProcessors(Parameters parameters) {
+            return Map.of("foo", (factories, tag, description, config, ctx) -> null);
         }
 
-        public Map<String, Processor.Factory<SearchResponseProcessor>> getResponseProcessors(Processor.Parameters parameters) {
-            return Map.of("bar", (factories, tag, description, config) -> null);
+        public Map<String, Processor.Factory<SearchResponseProcessor>> getResponseProcessors(Parameters parameters) {
+            return Map.of("bar", (factories, tag, description, config, ctx) -> null);
         }
 
         @Override
-        public Map<String, Processor.Factory<SearchPhaseResultsProcessor>> getSearchPhaseResultsProcessors(
-            Processor.Parameters parameters
-        ) {
-            return Map.of("zoe", (factories, tag, description, config) -> null);
+        public Map<String, Processor.Factory<SearchPhaseResultsProcessor>> getSearchPhaseResultsProcessors(Parameters parameters) {
+            return Map.of("zoe", (factories, tag, description, config, ctx) -> null);
         }
     };
 
@@ -303,7 +301,7 @@ public SearchPhaseName getAfterPhase() {
 
     private SearchPipelineService createWithProcessors() {
         Map<String, Processor.Factory<SearchRequestProcessor>> requestProcessors = new HashMap<>();
-        requestProcessors.put("scale_request_size", (processorFactories, tag, description, config) -> {
+        requestProcessors.put("scale_request_size", (processorFactories, tag, description, config, ctx) -> {
             float scale = ((Number) config.remove("scale")).floatValue();
             return new FakeRequestProcessor(
                 "scale_request_size",
@@ -313,13 +311,13 @@ private SearchPipelineService createWithProcessors() {
             );
         });
         Map<String, Processor.Factory<SearchResponseProcessor>> responseProcessors = new HashMap<>();
-        responseProcessors.put("fixed_score", (processorFactories, tag, description, config) -> {
+        responseProcessors.put("fixed_score", (processorFactories, tag, description, config, ctx) -> {
             float score = ((Number) config.remove("score")).floatValue();
             return new FakeResponseProcessor("fixed_score", tag, description, rsp -> rsp.getHits().forEach(h -> h.score(score)));
         });
 
         Map<String, Processor.Factory<SearchPhaseResultsProcessor>> searchPhaseProcessors = new HashMap<>();
-        searchPhaseProcessors.put("max_score", (processorFactories, tag, description, config) -> {
+        searchPhaseProcessors.put("max_score", (processorFactories, tag, description, config, context) -> {
             final float finalScore = config.containsKey("score") ? ((Number) config.remove("score")).floatValue() : 100f;
             final Consumer<SearchPhaseResult> querySearchResultConsumer = (result) -> result.queryResult().topDocs().maxScore = finalScore;
             return new FakeSearchPhaseResultsProcessor("max_score", tag, description, querySearchResultConsumer);
@@ -354,19 +352,17 @@ private SearchPipelineService createWithProcessors(
             this.writableRegistry(),
             Collections.singletonList(new SearchPipelinePlugin() {
                 @Override
-                public Map<String, Processor.Factory<SearchRequestProcessor>> getRequestProcessors(Processor.Parameters parameters) {
+                public Map<String, Processor.Factory<SearchRequestProcessor>> getRequestProcessors(Parameters parameters) {
                     return requestProcessors;
                 }
 
                 @Override
-                public Map<String, Processor.Factory<SearchResponseProcessor>> getResponseProcessors(Processor.Parameters parameters) {
+                public Map<String, Processor.Factory<SearchResponseProcessor>> getResponseProcessors(Parameters parameters) {
                     return responseProcessors;
                 }
 
                 @Override
-                public Map<String, Processor.Factory<SearchPhaseResultsProcessor>> getSearchPhaseResultsProcessors(
-                    Processor.Parameters parameters
-                ) {
+                public Map<String, Processor.Factory<SearchPhaseResultsProcessor>> getSearchPhaseResultsProcessors(Parameters parameters) {
                     return phaseProcessors;
                 }
 
@@ -897,10 +893,9 @@ public void testInfo() {
     }
 
     public void testExceptionOnPipelineCreation() {
-        Map<String, Processor.Factory<SearchRequestProcessor>> badFactory = Map.of(
-            "bad_factory",
-            (pf, t, f, c) -> { throw new RuntimeException(); }
-        );
+        Map<String, Processor.Factory<SearchRequestProcessor>> badFactory = Map.of("bad_factory", (pf, t, f, c, ctx) -> {
+            throw new RuntimeException();
+        });
         SearchPipelineService searchPipelineService = createWithProcessors(badFactory, Collections.emptyMap(), Collections.emptyMap());
 
         Map<String, Object> pipelineSourceMap = new HashMap<>();
@@ -920,7 +915,7 @@ public void testExceptionOnRequestProcessing() {
         });
         Map<String, Processor.Factory<SearchRequestProcessor>> throwingRequestProcessorFactory = Map.of(
             "throwing_request",
-            (pf, t, f, c) -> throwingRequestProcessor
+            (pf, t, f, c, ctx) -> throwingRequestProcessor
         );
 
         SearchPipelineService searchPipelineService = createWithProcessors(
@@ -945,7 +940,7 @@ public void testExceptionOnResponseProcessing() throws Exception {
         });
         Map<String, Processor.Factory<SearchResponseProcessor>> throwingResponseProcessorFactory = Map.of(
             "throwing_response",
-            (pf, t, f, c) -> throwingResponseProcessor
+            (pf, t, f, c, ctx) -> throwingResponseProcessor
         );
 
         SearchPipelineService searchPipelineService = createWithProcessors(
@@ -955,7 +950,7 @@ public void testExceptionOnResponseProcessing() throws Exception {
         );
 
         Map<String, Object> pipelineSourceMap = new HashMap<>();
-        pipelineSourceMap.put(Pipeline.RESPONSE_PROCESSORS_KEY, List.of(Map.of("throwing_response", Collections.emptyMap())));
+        pipelineSourceMap.put(Pipeline.RESPONSE_PROCESSORS_KEY, List.of(Map.of("throwing_response", new HashMap<>())));
 
         SearchSourceBuilder sourceBuilder = SearchSourceBuilder.searchSource().size(100).searchPipelineSource(pipelineSourceMap);
         SearchRequest searchRequest = new SearchRequest().source(sourceBuilder);
@@ -973,18 +968,18 @@ public void testStats() throws Exception {
         });
         Map<String, Processor.Factory<SearchRequestProcessor>> requestProcessors = Map.of(
             "successful_request",
-            (pf, t, f, c) -> new FakeRequestProcessor("successful_request", "2", null, r -> {}),
+            (pf, t, f, c, ctx) -> new FakeRequestProcessor("successful_request", "2", null, r -> {}),
             "throwing_request",
-            (pf, t, f, c) -> throwingRequestProcessor
+            (pf, t, f, c, ctx) -> throwingRequestProcessor
         );
         SearchResponseProcessor throwingResponseProcessor = new FakeResponseProcessor("throwing_response", "3", null, r -> {
             throw new RuntimeException();
         });
         Map<String, Processor.Factory<SearchResponseProcessor>> responseProcessors = Map.of(
             "successful_response",
-            (pf, t, f, c) -> new FakeResponseProcessor("successful_response", "4", null, r -> {}),
+            (pf, t, f, c, ctx) -> new FakeResponseProcessor("successful_response", "4", null, r -> {}),
             "throwing_response",
-            (pf, t, f, c) -> throwingResponseProcessor
+            (pf, t, f, c, ctx) -> throwingResponseProcessor
         );
         SearchPipelineService searchPipelineService = createWithProcessors(requestProcessors, responseProcessors, Collections.emptyMap());
 
@@ -1088,4 +1083,64 @@ private static void assertPipelineStats(OperationStats stats, long count, long f
         assertEquals(stats.getCount(), count);
         assertEquals(stats.getFailedCount(), failed);
     }
+
+    public void testAdHocRejectingProcessor() {
+        String processorType = "ad_hoc_rejecting";
+        Map<String, Processor.Factory<SearchRequestProcessor>> requestProcessorFactories = Map.of(processorType, (pf, t, d, c, ctx) -> {
+            if (ctx.getPipelineSource() == Processor.PipelineSource.SEARCH_REQUEST) {
+                throw new IllegalArgumentException(processorType + " cannot be created as part of a pipeline defined in a search request");
+            }
+            return new FakeRequestProcessor(processorType, t, d, r -> {});
+        });
+
+        SearchPipelineService searchPipelineService = createWithProcessors(
+            requestProcessorFactories,
+            Collections.emptyMap(),
+            Collections.emptyMap()
+        );
+
+        String id = "_id";
+        SearchPipelineService.PipelineHolder pipeline = searchPipelineService.getPipelines().get(id);
+        assertNull(pipeline);
+        ClusterState clusterState = ClusterState.builder(new ClusterName("_name")).build();
+        PutSearchPipelineRequest putRequest = new PutSearchPipelineRequest(
+            id,
+            new BytesArray("{\"request_processors\":[" + " { \"" + processorType + "\": {}}" + "]}"),
+            XContentType.JSON
+        );
+        ClusterState previousClusterState = clusterState;
+        clusterState = SearchPipelineService.innerPut(putRequest, clusterState);
+        // The following line successfully creates the pipeline:
+        searchPipelineService.applyClusterState(new ClusterChangedEvent("", clusterState, previousClusterState));
+
+        Map<String, Object> pipelineSourceMap = new HashMap<>();
+        pipelineSourceMap.put(Pipeline.REQUEST_PROCESSORS_KEY, List.of(Map.of(processorType, Collections.emptyMap())));
+
+        SearchSourceBuilder sourceBuilder = SearchSourceBuilder.searchSource().searchPipelineSource(pipelineSourceMap);
+        SearchRequest searchRequest = new SearchRequest().source(sourceBuilder);
+        expectThrows(SearchPipelineProcessingException.class, () -> searchPipelineService.resolvePipeline(searchRequest));
+    }
+
+    public void testExtraParameterInProcessorConfig() {
+        SearchPipelineService searchPipelineService = createWithProcessors();
+
+        Map<String, Object> pipelineSourceMap = new HashMap<>();
+        Map<String, Object> processorConfig = new HashMap<>(
+            Map.of("score", 1.0f, "tag", "my_tag", "comment", "I just like to add extra parameters so that I feel like I'm being heard.")
+        );
+        pipelineSourceMap.put(Pipeline.RESPONSE_PROCESSORS_KEY, List.of(Map.of("fixed_score", processorConfig)));
+        SearchSourceBuilder sourceBuilder = SearchSourceBuilder.searchSource().searchPipelineSource(pipelineSourceMap);
+        SearchRequest searchRequest = new SearchRequest().source(sourceBuilder);
+        try {
+            searchPipelineService.resolvePipeline(searchRequest);
+            fail("Exception should have been thrown");
+        } catch (SearchPipelineProcessingException e) {
+            assertTrue(
+                e.getMessage()
+                    .contains("processor [fixed_score:my_tag] doesn't support one or more provided configuration parameters: [comment]")
+            );
+        } catch (Exception e) {
+            fail("Wrong exception type: " + e.getClass());
+        }
+    }
 }
diff --git a/server/src/test/java/org/opensearch/snapshots/SnapshotResiliencyTests.java b/server/src/test/java/org/opensearch/snapshots/SnapshotResiliencyTests.java
index 0bb2b604e8f1a..88899a1b282af 100644
--- a/server/src/test/java/org/opensearch/snapshots/SnapshotResiliencyTests.java
+++ b/server/src/test/java/org/opensearch/snapshots/SnapshotResiliencyTests.java
@@ -1835,7 +1835,7 @@ public void onFailure(final Exception e) {
                     emptyMap(),
                     null,
                     emptyMap(),
-                    new RemoteSegmentStoreDirectoryFactory(() -> repositoriesService),
+                    new RemoteSegmentStoreDirectoryFactory(() -> repositoriesService, threadPool),
                     repositoriesServiceReference::get,
                     fileCacheCleaner
                 );
diff --git a/server/src/test/java/org/opensearch/telemetry/tracing/TracerFactoryTests.java b/server/src/test/java/org/opensearch/telemetry/tracing/TracerFactoryTests.java
index 7968c6c43afb4..df9cdd6669d23 100644
--- a/server/src/test/java/org/opensearch/telemetry/tracing/TracerFactoryTests.java
+++ b/server/src/test/java/org/opensearch/telemetry/tracing/TracerFactoryTests.java
@@ -45,7 +45,7 @@ public void testGetTracerWithTracingDisabledReturnsNoopTracer() {
 
         Tracer tracer = tracerFactory.getTracer();
         assertTrue(tracer instanceof NoopTracer);
-        assertTrue(tracer.startSpan("foo") == Scope.NO_OP);
+        assertTrue(tracer.startSpan("foo") == SpanScope.NO_OP);
     }
 
     public void testGetTracerWithTracingEnabledReturnsDefaultTracer() {
diff --git a/settings.gradle b/settings.gradle
index bf899d04c1e08..b7d47cd9b745e 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -10,7 +10,7 @@
  */
 
 plugins {
-  id "com.gradle.enterprise" version "3.11.1"
+  id "com.gradle.enterprise" version "3.13.3"
 }
 
 buildCache {
@@ -87,7 +87,8 @@ List projects = [
   'test:fixtures:minio-fixture',
   'test:fixtures:old-elasticsearch',
   'test:fixtures:s3-fixture',
-  'test:logger-usage'
+  'test:logger-usage',
+  'test:telemetry'
 ]
 
 /**
diff --git a/test/framework/build.gradle b/test/framework/build.gradle
index 255f554db7a79..2532fdf1938fd 100644
--- a/test/framework/build.gradle
+++ b/test/framework/build.gradle
@@ -38,6 +38,7 @@ dependencies {
   api project(':libs:opensearch-nio')
   api project(":server")
   api project(":libs:opensearch-cli")
+  api project(":test:telemetry")
   api "com.carrotsearch.randomizedtesting:randomizedtesting-runner:${versions.randomizedrunner}"
   api "junit:junit:${versions.junit}"
   api "org.hamcrest:hamcrest:${versions.hamcrest}"
diff --git a/test/framework/src/main/java/org/opensearch/index/shard/IndexShardTestCase.java b/test/framework/src/main/java/org/opensearch/index/shard/IndexShardTestCase.java
index ea9e9342673db..7f3819563dcbd 100644
--- a/test/framework/src/main/java/org/opensearch/index/shard/IndexShardTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/index/shard/IndexShardTestCase.java
@@ -666,7 +666,7 @@ protected RemoteSegmentStoreDirectory createRemoteSegmentStoreDirectory(ShardId
         RemoteStoreLockManager remoteStoreLockManager = new RemoteStoreMetadataLockManager(
             new RemoteBufferedOutputDirectory(getBlobContainer(remoteShardPath.resolveIndex()))
         );
-        return new RemoteSegmentStoreDirectory(dataDirectory, metadataDirectory, remoteStoreLockManager);
+        return new RemoteSegmentStoreDirectory(dataDirectory, metadataDirectory, remoteStoreLockManager, threadPool);
     }
 
     private RemoteDirectory newRemoteDirectory(Path f) throws IOException {
diff --git a/test/framework/src/main/java/org/opensearch/index/shard/RestoreOnlyRepository.java b/test/framework/src/main/java/org/opensearch/index/shard/RestoreOnlyRepository.java
index 2a85fffa8699a..67f3f7fc1f50c 100644
--- a/test/framework/src/main/java/org/opensearch/index/shard/RestoreOnlyRepository.java
+++ b/test/framework/src/main/java/org/opensearch/index/shard/RestoreOnlyRepository.java
@@ -44,6 +44,7 @@
 import org.opensearch.index.mapper.MapperService;
 import org.opensearch.index.snapshots.IndexShardSnapshotStatus;
 import org.opensearch.index.store.Store;
+import org.opensearch.index.store.lockmanager.RemoteStoreLockManagerFactory;
 import org.opensearch.repositories.IndexId;
 import org.opensearch.repositories.IndexMetaDataGenerations;
 import org.opensearch.repositories.Repository;
@@ -205,4 +206,16 @@ public void cloneShardSnapshot(
     ) {
         throw new UnsupportedOperationException("Unsupported for restore-only repository");
     }
+
+    @Override
+    public void cloneRemoteStoreIndexShardSnapshot(
+        SnapshotId source,
+        SnapshotId target,
+        RepositoryShardId shardId,
+        String shardGeneration,
+        RemoteStoreLockManagerFactory remoteStoreLockManagerFactory,
+        ActionListener<String> listener
+    ) {
+        throw new UnsupportedOperationException("Unsupported for restore-only repository");
+    }
 }
diff --git a/test/framework/src/main/java/org/opensearch/snapshots/AbstractSnapshotIntegTestCase.java b/test/framework/src/main/java/org/opensearch/snapshots/AbstractSnapshotIntegTestCase.java
index ddf9f3e96b9b4..83051c7fed4e4 100644
--- a/test/framework/src/main/java/org/opensearch/snapshots/AbstractSnapshotIntegTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/snapshots/AbstractSnapshotIntegTestCase.java
@@ -51,6 +51,8 @@
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.Strings;
 import org.opensearch.common.UUIDs;
+import org.opensearch.common.blobstore.BlobContainer;
+import org.opensearch.common.blobstore.BlobPath;
 import org.opensearch.common.bytes.BytesReference;
 import org.opensearch.common.compress.CompressorType;
 import org.opensearch.common.settings.Settings;
@@ -61,6 +63,9 @@
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.common.xcontent.json.JsonXContent;
+import org.opensearch.index.IndexModule;
+import org.opensearch.index.store.RemoteBufferedOutputDirectory;
+import org.opensearch.indices.replication.common.ReplicationType;
 import org.opensearch.node.NodeClosedException;
 import org.opensearch.plugins.Plugin;
 import org.opensearch.repositories.RepositoriesService;
@@ -511,6 +516,26 @@ protected void indexRandomDocs(String index, int numdocs) throws InterruptedExce
         assertDocCount(index, numdocs);
     }
 
+    protected Settings getRemoteStoreBackedIndexSettings(String remoteStoreRepo) {
+        return Settings.builder()
+            .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, "1")
+            .put("index.refresh_interval", "300s")
+            .put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, "1")
+            .put(IndexModule.INDEX_STORE_TYPE_SETTING.getKey(), IndexModule.Type.FS.getSettingsKey())
+            .put(IndexModule.INDEX_QUERY_CACHE_ENABLED_SETTING.getKey(), false)
+            .put(IndexMetadata.SETTING_REPLICATION_TYPE, ReplicationType.SEGMENT)
+            .put(IndexMetadata.SETTING_REMOTE_STORE_ENABLED, true)
+            .put(IndexMetadata.SETTING_REMOTE_STORE_REPOSITORY, remoteStoreRepo)
+            .build();
+    }
+
+    protected Settings.Builder snapshotRepoSettingsForShallowCopy(Path path) {
+        final Settings.Builder settings = Settings.builder();
+        settings.put("location", path);
+        settings.put(BlobStoreRepository.REMOTE_STORE_INDEX_SHALLOW_COPY.getKey(), Boolean.TRUE);
+        return settings;
+    }
+
     protected long getCountForIndex(String indexName) {
         return client().search(
             new SearchRequest(new SearchRequest(indexName).source(new SearchSourceBuilder().size(0).trackTotalHits(true)))
@@ -521,6 +546,21 @@ protected void assertDocCount(String index, long count) {
         assertEquals(getCountForIndex(index), count);
     }
 
+    protected String[] getLockFilesInRemoteStore(String remoteStoreIndex, String remoteStoreRepositoryName) throws IOException {
+        String indexUUID = client().admin()
+            .indices()
+            .prepareGetSettings(remoteStoreIndex)
+            .get()
+            .getSetting(remoteStoreIndex, IndexMetadata.SETTING_INDEX_UUID);
+        final RepositoriesService repositoriesService = internalCluster().getCurrentClusterManagerNodeInstance(RepositoriesService.class);
+        final BlobStoreRepository remoteStoreRepository = (BlobStoreRepository) repositoriesService.repository(remoteStoreRepositoryName);
+        BlobPath shardLevelBlobPath = remoteStoreRepository.basePath().add(indexUUID).add("0").add("segments").add("lock_files");
+        BlobContainer blobContainer = remoteStoreRepository.blobStore().blobContainer(shardLevelBlobPath);
+        try (RemoteBufferedOutputDirectory lockDirectory = new RemoteBufferedOutputDirectory(blobContainer)) {
+            return lockDirectory.listAll();
+        }
+    }
+
     /**
      * Adds a snapshot in state {@link SnapshotState#FAILED} to the given repository.
      *
diff --git a/test/framework/src/main/java/org/opensearch/test/OpenSearchIntegTestCase.java b/test/framework/src/main/java/org/opensearch/test/OpenSearchIntegTestCase.java
index caa5b90016740..fec45219ace81 100644
--- a/test/framework/src/main/java/org/opensearch/test/OpenSearchIntegTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/test/OpenSearchIntegTestCase.java
@@ -109,6 +109,7 @@
 import org.opensearch.common.unit.ByteSizeUnit;
 import org.opensearch.common.unit.ByteSizeValue;
 import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.util.concurrent.ThreadContext;
 import org.opensearch.common.xcontent.XContentHelper;
 import org.opensearch.common.xcontent.XContentType;
@@ -152,6 +153,7 @@
 import org.opensearch.test.disruption.ServiceDisruptionScheme;
 import org.opensearch.test.store.MockFSIndexStore;
 import org.opensearch.test.transport.MockTransportService;
+import org.opensearch.test.telemetry.MockTelemetryPlugin;
 import org.opensearch.transport.TransportInterceptor;
 import org.opensearch.transport.TransportRequest;
 import org.opensearch.transport.TransportRequestHandler;
@@ -776,6 +778,7 @@ protected Settings featureFlagSettings() {
         for (Setting builtInFlag : FeatureFlagSettings.BUILT_IN_FEATURE_FLAGS) {
             featureSettings.put(builtInFlag.getKey(), builtInFlag.getDefaultRaw(Settings.EMPTY));
         }
+        featureSettings.put(FeatureFlags.TELEMETRY_SETTING.getKey(), true);
         return featureSettings.build();
     }
 
@@ -2101,6 +2104,7 @@ protected Collection<Class<? extends Plugin>> getMockPlugins() {
         if (addMockGeoShapeFieldMapper()) {
             mocks.add(TestGeoShapeFieldMapperPlugin.class);
         }
+        mocks.add(MockTelemetryPlugin.class);
 
         return Collections.unmodifiableList(mocks);
     }
diff --git a/test/framework/src/main/java/org/opensearch/test/OpenSearchSingleNodeTestCase.java b/test/framework/src/main/java/org/opensearch/test/OpenSearchSingleNodeTestCase.java
index bf797ef6b310b..91c48f1679f9a 100644
--- a/test/framework/src/main/java/org/opensearch/test/OpenSearchSingleNodeTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/test/OpenSearchSingleNodeTestCase.java
@@ -48,6 +48,7 @@
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.common.util.BigArrays;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.common.util.concurrent.OpenSearchExecutors;
 import org.opensearch.common.util.io.IOUtils;
 import org.opensearch.core.common.Strings;
@@ -66,6 +67,8 @@
 import org.opensearch.plugins.Plugin;
 import org.opensearch.script.MockScriptService;
 import org.opensearch.search.internal.SearchContext;
+import org.opensearch.telemetry.TelemetrySettings;
+import org.opensearch.test.telemetry.MockTelemetryPlugin;
 import org.opensearch.transport.TransportSettings;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
@@ -242,6 +245,8 @@ private Node newNode() {
             .put(HierarchyCircuitBreakerService.USE_REAL_MEMORY_USAGE_SETTING.getKey(), false)
             .putList(DISCOVERY_SEED_HOSTS_SETTING.getKey()) // empty list disables a port scan for other nodes
             .putList(INITIAL_CLUSTER_MANAGER_NODES_SETTING.getKey(), nodeName)
+            .put(FeatureFlags.TELEMETRY_SETTING.getKey(), true)
+            .put(TelemetrySettings.TRACER_ENABLED_SETTING.getKey(), true)
             .put(nodeSettings()) // allow test cases to provide their own settings or override these
             .build();
 
@@ -254,6 +259,7 @@ private Node newNode() {
             plugins.add(MockHttpTransport.TestPlugin.class);
         }
         plugins.add(MockScriptService.TestPlugin.class);
+        plugins.add(MockTelemetryPlugin.class);
         Node node = new MockNode(settings, plugins, forbidPrivateIndexSettings());
         try {
             node.start();
diff --git a/test/framework/src/main/java/org/opensearch/test/telemetry/MockTelemetry.java b/test/framework/src/main/java/org/opensearch/test/telemetry/MockTelemetry.java
new file mode 100644
index 0000000000000..c02ab1d737303
--- /dev/null
+++ b/test/framework/src/main/java/org/opensearch/test/telemetry/MockTelemetry.java
@@ -0,0 +1,42 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.test.telemetry;
+
+import org.opensearch.telemetry.Telemetry;
+import org.opensearch.telemetry.TelemetrySettings;
+import org.opensearch.telemetry.metrics.MetricsTelemetry;
+import org.opensearch.test.telemetry.tracing.MockTracingTelemetry;
+import org.opensearch.telemetry.tracing.TracingTelemetry;
+
+/**
+ * Mock {@link Telemetry} implementation for testing.
+ */
+public class MockTelemetry implements Telemetry {
+
+    private final TelemetrySettings settings;
+
+    /**
+     * Constructor with settings.
+     * @param settings telemetry settings.
+     */
+    public MockTelemetry(TelemetrySettings settings) {
+        this.settings = settings;
+    }
+
+    @Override
+    public TracingTelemetry getTracingTelemetry() {
+        return new MockTracingTelemetry();
+    }
+
+    @Override
+    public MetricsTelemetry getMetricsTelemetry() {
+        return new MetricsTelemetry() {
+        };
+    }
+}
diff --git a/test/framework/src/main/java/org/opensearch/test/telemetry/MockTelemetryPlugin.java b/test/framework/src/main/java/org/opensearch/test/telemetry/MockTelemetryPlugin.java
new file mode 100644
index 0000000000000..41cc5c1e77a34
--- /dev/null
+++ b/test/framework/src/main/java/org/opensearch/test/telemetry/MockTelemetryPlugin.java
@@ -0,0 +1,39 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.test.telemetry;
+
+import java.util.Optional;
+import org.opensearch.plugins.Plugin;
+import org.opensearch.plugins.TelemetryPlugin;
+import org.opensearch.telemetry.Telemetry;
+import org.opensearch.telemetry.TelemetrySettings;
+
+/**
+ * Mock {@link TelemetryPlugin} implementation for testing.
+ */
+public class MockTelemetryPlugin extends Plugin implements TelemetryPlugin {
+    private static final String MOCK_TRACER_NAME = "mock";
+
+    /**
+     * Base constructor.
+     */
+    public MockTelemetryPlugin() {
+
+    }
+
+    @Override
+    public Optional<Telemetry> getTelemetry(TelemetrySettings settings) {
+        return Optional.of(new MockTelemetry(settings));
+    }
+
+    @Override
+    public String getName() {
+        return MOCK_TRACER_NAME;
+    }
+}
diff --git a/test/telemetry/build.gradle b/test/telemetry/build.gradle
new file mode 100644
index 0000000000000..fbabe43aa5e5a
--- /dev/null
+++ b/test/telemetry/build.gradle
@@ -0,0 +1,25 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+apply plugin: 'opensearch.build'
+apply plugin: 'opensearch.publish'
+
+dependencies {
+  api project(":libs:opensearch-common")
+  api project(":libs:opensearch-telemetry")
+}
+
+tasks.named('forbiddenApisMain').configure {
+  //package does not depend on core, so only jdk signatures should be checked
+  replaceSignatureFiles 'jdk-signatures'
+}
+
+test.enabled = false
diff --git a/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/MockSpan.java b/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/MockSpan.java
new file mode 100644
index 0000000000000..876145f6bf653
--- /dev/null
+++ b/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/MockSpan.java
@@ -0,0 +1,163 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.test.telemetry.tracing;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Random;
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.function.Supplier;
+import org.opensearch.telemetry.tracing.AbstractSpan;
+import org.opensearch.telemetry.tracing.Span;
+
+/**
+ * MockSpan for testing and strict check validations. Not to be used for production cases.
+ */
+public class MockSpan extends AbstractSpan {
+    private final SpanProcessor spanProcessor;
+    private final Map<String, Object> metadata;
+    private final String traceId;
+    private final String spanId;
+    private boolean hasEnded;
+    private final Long startTime;
+    private Long endTime;
+
+    private final Object lock = new Object();
+
+    private static final Supplier<Random> randomSupplier = ThreadLocalRandom::current;
+
+    /**
+     * Base Constructor.
+     * @param spanName span name
+     * @param parentSpan parent span
+     * @param spanProcessor span processor
+     */
+    public MockSpan(String spanName, Span parentSpan, SpanProcessor spanProcessor) {
+        this(
+            spanName,
+            parentSpan,
+            parentSpan != null ? parentSpan.getTraceId() : IdGenerator.generateTraceId(),
+            IdGenerator.generateSpanId(),
+            spanProcessor
+        );
+    }
+
+    /**
+     * Constructor with traceId and SpanIds
+     * @param spanName  Span Name
+     * @param parentSpan  Parent Span
+     * @param traceId  Trace ID
+     * @param spanId  Span ID
+     * @param spanProcessor  Span Processor
+     */
+    public MockSpan(String spanName, Span parentSpan, String traceId, String spanId, SpanProcessor spanProcessor) {
+        super(spanName, parentSpan);
+        this.spanProcessor = spanProcessor;
+        this.metadata = new HashMap<>();
+        this.traceId = traceId;
+        this.spanId = spanId;
+        this.startTime = System.nanoTime();
+    }
+
+    @Override
+    public void endSpan() {
+        synchronized (lock) {
+            if (hasEnded) {
+                return;
+            }
+            endTime = System.nanoTime();
+            hasEnded = true;
+        }
+        spanProcessor.onEnd(this);
+    }
+
+    @Override
+    public void addAttribute(String key, String value) {
+        putMetadata(key, value);
+    }
+
+    @Override
+    public void addAttribute(String key, Long value) {
+        putMetadata(key, value);
+    }
+
+    @Override
+    public void addAttribute(String key, Double value) {
+        putMetadata(key, value);
+    }
+
+    @Override
+    public void addAttribute(String key, Boolean value) {
+        putMetadata(key, value);
+    }
+
+    @Override
+    public void addEvent(String event) {
+        putMetadata(event, null);
+    }
+
+    private void putMetadata(String key, Object value) {
+        metadata.put(key, value);
+    }
+
+    @Override
+    public String getTraceId() {
+        return traceId;
+    }
+
+    @Override
+    public String getSpanId() {
+        return spanId;
+    }
+
+    /**
+     * Returns whether the span is ended or not.
+     * @return span end status.
+     */
+    public boolean hasEnded() {
+        synchronized (lock) {
+            return hasEnded;
+        }
+    }
+
+    /**
+     * Returns the start time of the span.
+     * @return start time of the span.
+     */
+    public Long getStartTime() {
+        return startTime;
+    }
+
+    /**
+     * Returns the start time of the span.
+     * @return end time of the span.
+     */
+    public Long getEndTime() {
+        return endTime;
+    }
+
+    public void setError(Exception exception) {
+        putMetadata("ERROR", exception.getMessage());
+    }
+
+    private static class IdGenerator {
+        private static String generateSpanId() {
+            long id = randomSupplier.get().nextLong();
+            return Long.toHexString(id);
+        }
+
+        private static String generateTraceId() {
+            long idHi = randomSupplier.get().nextLong();
+            long idLo = randomSupplier.get().nextLong();
+            long result = idLo | (idHi << 32);
+            return Long.toHexString(result);
+        }
+
+    }
+}
diff --git a/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/MockTracingContextPropagator.java b/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/MockTracingContextPropagator.java
new file mode 100644
index 0000000000000..7e3f5a9031100
--- /dev/null
+++ b/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/MockTracingContextPropagator.java
@@ -0,0 +1,56 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.test.telemetry.tracing;
+
+import java.util.Locale;
+import java.util.Map;
+import java.util.function.BiConsumer;
+import org.opensearch.telemetry.tracing.Span;
+import org.opensearch.telemetry.tracing.TracingContextPropagator;
+
+/**
+ * Mock {@link TracingContextPropagator} to persist the span for internode communication.
+ */
+public class MockTracingContextPropagator implements TracingContextPropagator {
+
+    private static final String TRACE_PARENT = "traceparent";
+    private static final String SEPARATOR = "~";
+    private final SpanProcessor spanProcessor;
+
+    /**
+     * Constructor
+     * @param spanProcessor span processor.
+     */
+    public MockTracingContextPropagator(SpanProcessor spanProcessor) {
+        this.spanProcessor = spanProcessor;
+    }
+
+    @Override
+    public Span extract(Map<String, String> props) {
+        String value = props.get(TRACE_PARENT);
+        if (value != null) {
+            String[] values = value.split(SEPARATOR);
+            String traceId = values[0];
+            String spanId = values[1];
+            return new MockSpan(null, null, traceId, spanId, spanProcessor);
+        } else {
+            return null;
+        }
+    }
+
+    @Override
+    public void inject(Span currentSpan, BiConsumer<String, String> setter) {
+        if (currentSpan instanceof MockSpan) {
+            String traceId = currentSpan.getTraceId();
+            String spanId = currentSpan.getSpanId();
+            String traceParent = String.format(Locale.ROOT, "%s%s%s", traceId, SEPARATOR, spanId);
+            setter.accept(TRACE_PARENT, traceParent);
+        }
+    }
+}
diff --git a/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/MockTracingTelemetry.java b/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/MockTracingTelemetry.java
new file mode 100644
index 0000000000000..531b4ce36c36a
--- /dev/null
+++ b/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/MockTracingTelemetry.java
@@ -0,0 +1,46 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.test.telemetry.tracing;
+
+import org.opensearch.telemetry.tracing.Span;
+import org.opensearch.telemetry.tracing.TracingContextPropagator;
+import org.opensearch.telemetry.tracing.TracingTelemetry;
+
+/**
+ * Mock {@link TracingTelemetry} implementation for testing.
+ */
+public class MockTracingTelemetry implements TracingTelemetry {
+
+    private final SpanProcessor spanProcessor = new StrictCheckSpanProcessor();
+
+    /**
+     * Base constructor.
+     */
+    public MockTracingTelemetry() {
+
+    }
+
+    @Override
+    public Span createSpan(String spanName, Span parentSpan) {
+        Span span = new MockSpan(spanName, parentSpan, spanProcessor);
+        spanProcessor.onStart(span);
+        return span;
+    }
+
+    @Override
+    public TracingContextPropagator getContextPropagator() {
+        return new MockTracingContextPropagator(spanProcessor);
+    }
+
+    @Override
+    public void close() {
+        ((StrictCheckSpanProcessor) spanProcessor).ensureAllSpansAreClosed();
+        ((StrictCheckSpanProcessor) spanProcessor).clear();
+    }
+}
diff --git a/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/SpanProcessor.java b/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/SpanProcessor.java
new file mode 100644
index 0000000000000..cb9d0dbd428e4
--- /dev/null
+++ b/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/SpanProcessor.java
@@ -0,0 +1,28 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.test.telemetry.tracing;
+
+import org.opensearch.telemetry.tracing.Span;
+
+/**
+ * Processes the span and can perform any action on the span start and end.
+ */
+public interface SpanProcessor {
+    /**
+     * Logic to be executed on span start.
+     * @param span span which is starting.
+     */
+    void onStart(Span span);
+
+    /**
+     * Logic to be executed on span end.
+     * @param span span which is ending.
+     */
+    void onEnd(Span span);
+}
diff --git a/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/StrictCheckSpanProcessor.java b/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/StrictCheckSpanProcessor.java
new file mode 100644
index 0000000000000..34d4d96809755
--- /dev/null
+++ b/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/StrictCheckSpanProcessor.java
@@ -0,0 +1,84 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.test.telemetry.tracing;
+
+import java.util.Arrays;
+import java.util.Locale;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import org.opensearch.telemetry.tracing.Span;
+
+/**
+ * Strict check span processor to validate the spans.
+ */
+public class StrictCheckSpanProcessor implements SpanProcessor {
+    private final Map<String, StackTraceElement[]> spanMap = new ConcurrentHashMap<>();
+
+    /**
+     * Base constructor.
+     */
+    public StrictCheckSpanProcessor() {
+
+    }
+
+    @Override
+    public void onStart(Span span) {
+        spanMap.put(span.getSpanId(), Thread.currentThread().getStackTrace());
+    }
+
+    @Override
+    public void onEnd(Span span) {
+        spanMap.remove(span.getSpanId());
+    }
+
+    /**
+     * Ensures that all the spans are closed. Throws exception message with stack trace of the method form
+     * where the span was created. We can enhance it to print all the failed spans in a single go based on
+     * the usability.
+     */
+    public void ensureAllSpansAreClosed() {
+        if (!spanMap.isEmpty()) {
+            for (Map.Entry<String, StackTraceElement[]> entry : spanMap.entrySet()) {
+                StackTraceElement[] filteredStackTrace = getFilteredStackTrace(entry.getValue());
+                AssertionError error = new AssertionError(
+                    String.format(
+                        Locale.ROOT,
+                        " Total [%d] spans are not ended properly. " + "Find below the stack trace for one of the un-ended span",
+                        spanMap.size()
+                    )
+                );
+                error.setStackTrace(filteredStackTrace);
+                spanMap.clear();
+                throw error;
+            }
+        }
+    }
+
+    /**
+     * Clears the state.
+     */
+    public void clear() {
+        spanMap.clear();
+    }
+
+    private StackTraceElement[] getFilteredStackTrace(StackTraceElement[] stackTraceElements) {
+        int filteredElementsCount = 0;
+        while (filteredElementsCount < stackTraceElements.length) {
+            String className = stackTraceElements[filteredElementsCount].getClassName();
+            if (className.startsWith("java.lang.Thread")
+                || className.startsWith("org.opensearch.telemetry")
+                || className.startsWith("org.opensearch.tracing")) {
+                filteredElementsCount++;
+            } else {
+                break;
+            }
+        }
+        return Arrays.copyOfRange(stackTraceElements, filteredElementsCount, stackTraceElements.length);
+    }
+}
diff --git a/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/package-info.java b/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/package-info.java
new file mode 100644
index 0000000000000..83e2b4035acbf
--- /dev/null
+++ b/test/telemetry/src/main/java/org/opensearch/test/telemetry/tracing/package-info.java
@@ -0,0 +1,10 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/** Base opensearch package. */
+package org.opensearch.test.telemetry.tracing;