diff --git a/buildSrc/src/main/java/org/elasticsearch/gradle/VersionCollection.java b/buildSrc/src/main/java/org/elasticsearch/gradle/VersionCollection.java
index e2af34dbabdc0..cf8eb1829abef 100644
--- a/buildSrc/src/main/java/org/elasticsearch/gradle/VersionCollection.java
+++ b/buildSrc/src/main/java/org/elasticsearch/gradle/VersionCollection.java
@@ -171,30 +171,38 @@ public UnreleasedVersionInfo unreleasedInfo(Version version) {
     }
 
     public void forPreviousUnreleased(Consumer<UnreleasedVersionInfo> consumer) {
-        getUnreleased().stream()
+        List<UnreleasedVersionInfo> collect = getUnreleased().stream()
             .filter(version -> version.equals(currentVersion) == false)
-            .forEach(version -> consumer.accept(
-                new UnreleasedVersionInfo(
+            .map(version -> new UnreleasedVersionInfo(
                     version,
                     getBranchFor(version),
                     getGradleProjectNameFor(version)
                 )
-            ));
+            )
+            .collect(Collectors.toList());
+
+        collect.forEach(uvi -> consumer.accept(uvi));
     }
 
     private String getGradleProjectNameFor(Version version) {
         if (version.equals(currentVersion)) {
             throw new IllegalArgumentException("The Gradle project to build " + version + " is the current build.");
         }
+
         Map<Integer, List<Version>> releasedMajorGroupedByMinor = getReleasedMajorGroupedByMinor();
 
         if (version.getRevision() == 0) {
-            if (releasedMajorGroupedByMinor
-                .get(releasedMajorGroupedByMinor.keySet().stream().max(Integer::compareTo).orElse(0))
-                .contains(version)) {
-                return "minor";
+            List<Version> unreleasedStagedOrMinor = getUnreleased().stream()
+                .filter(v -> v.getRevision() == 0)
+                .collect(Collectors.toList());
+            if (unreleasedStagedOrMinor.size() > 2) {
+                if (unreleasedStagedOrMinor.get(unreleasedStagedOrMinor.size() - 2).equals(version)) {
+                    return "minor";
+                } else{
+                    return "staged";
+                }
             } else {
-                return "staged";
+                return "minor";
             }
         } else {
             if (releasedMajorGroupedByMinor
@@ -239,8 +247,10 @@ public List<Version> getUnreleased() {
             unreleased.add(getLatestVersionByKey(groupByMinor, greatestMinor - 1));
             if (groupByMinor.getOrDefault(greatestMinor - 1, emptyList()).size() == 1) {
                 // we found that the previous minor is staged but not yet released
-                // in this case, the minor before that has a bugfix
-                unreleased.add(getLatestVersionByKey(groupByMinor, greatestMinor - 2));
+                // in this case, the minor before that has a bugfix, should there be such a minor
+                if (greatestMinor >= 2) {
+                    unreleased.add(getLatestVersionByKey(groupByMinor, greatestMinor - 2));
+                }
             }
         }
 
diff --git a/buildSrc/src/test/java/org/elasticsearch/gradle/VersionCollectionTests.java b/buildSrc/src/test/java/org/elasticsearch/gradle/VersionCollectionTests.java
index d1b4e893ec6ad..4ea33b240e532 100644
--- a/buildSrc/src/test/java/org/elasticsearch/gradle/VersionCollectionTests.java
+++ b/buildSrc/src/test/java/org/elasticsearch/gradle/VersionCollectionTests.java
@@ -81,6 +81,9 @@ public class VersionCollectionTests extends GradleUnitTestCase {
             "6_0_0", "6_0_1", "6_1_0", "6_1_1", "6_1_2", "6_1_3", "6_1_4", "6_2_0", "6_2_1", "6_2_2", "6_2_3",
             "6_2_4", "6_3_0", "6_3_1", "6_3_2", "6_4_0", "6_4_1", "6_4_2"
         ));
+        sampleVersions.put("7.1.0", asList(
+            "7_1_0", "7_0_0", "6_7_0", "6_6_1", "6_6_0"
+        ));
     }
 
     @Test(expected = IllegalArgumentException.class)
@@ -145,6 +148,11 @@ public void testWireCompatible() {
             singletonList("7.3.0"),
             getVersionCollection("8.0.0").getWireCompatible()
         );
+        assertVersionsEquals(
+            asList("6.7.0", "7.0.0"),
+            getVersionCollection("7.1.0").getWireCompatible()
+        );
+
     }
 
     public void testWireCompatibleUnreleased() {
@@ -171,6 +179,10 @@ public void testWireCompatibleUnreleased() {
             singletonList("7.3.0"),
             getVersionCollection("8.0.0").getUnreleasedWireCompatible()
         );
+        assertVersionsEquals(
+            asList("6.7.0", "7.0.0"),
+            getVersionCollection("7.1.0").getWireCompatible()
+        );
     }
 
     public void testIndexCompatible() {
@@ -286,7 +298,7 @@ public void testGetBranch() {
             getVersionCollection("6.4.2")
         );
         assertUnreleasedBranchNames(
-            asList("5.6", "6.4", "6.5"),
+            asList("5.6", "6.4", "6.x"),
             getVersionCollection("6.6.0")
         );
         assertUnreleasedBranchNames(
@@ -309,13 +321,17 @@ public void testGetGradleProjectName() {
             getVersionCollection("6.4.2")
         );
         assertUnreleasedGradleProjectNames(
-            asList("maintenance", "bugfix", "staged"),
+            asList("maintenance", "bugfix", "minor"),
             getVersionCollection("6.6.0")
         );
         assertUnreleasedGradleProjectNames(
             asList("bugfix", "staged", "minor"),
             getVersionCollection("8.0.0")
         );
+        assertUnreleasedGradleProjectNames(
+            asList("staged", "minor"),
+            getVersionCollection("7.1.0")
+        );
     }
 
     public void testCompareToAuthoritative() {
diff --git a/buildSrc/version.properties b/buildSrc/version.properties
index 118ab2f905f74..e6aadf6b82055 100644
--- a/buildSrc/version.properties
+++ b/buildSrc/version.properties
@@ -1,4 +1,4 @@
-elasticsearch     = 7.0.0
+elasticsearch     = 8.0.0
 lucene            = 8.0.0-snapshot-83f9835
 
 # optional dependencies
diff --git a/distribution/bwc/build.gradle b/distribution/bwc/build.gradle
index 0ee597b449a41..ff111ecaa08ca 100644
--- a/distribution/bwc/build.gradle
+++ b/distribution/bwc/build.gradle
@@ -141,6 +141,12 @@ bwcVersions.forPreviousUnreleased { VersionCollection.UnreleasedVersionInfo unre
             extension += '.gz'
           }
         }
+        if (bwcVersion.onOrAfter('7.0.0') && projectName.contains('deb')) {
+          classifier = "-amd64"
+        }
+        if (bwcVersion.onOrAfter('7.0.0') && projectName.contains('rpm')) {
+          classifier = "-x86_64"
+        }
         if (bwcVersion.onOrAfter('6.3.0')) {
             baseDir += projectName.endsWith('zip') || projectName.endsWith('tar') ? '/archives' : '/packages'
             // add oss variant first
diff --git a/distribution/tools/plugin-cli/src/test/java/org/elasticsearch/plugins/RemovePluginCommandTests.java b/distribution/tools/plugin-cli/src/test/java/org/elasticsearch/plugins/RemovePluginCommandTests.java
index c62d37a4e28d8..415be8f2bbd19 100644
--- a/distribution/tools/plugin-cli/src/test/java/org/elasticsearch/plugins/RemovePluginCommandTests.java
+++ b/distribution/tools/plugin-cli/src/test/java/org/elasticsearch/plugins/RemovePluginCommandTests.java
@@ -137,12 +137,21 @@ public void testBasic() throws Exception {
     }
 
     public void testRemoveOldVersion() throws Exception {
+        Version previous = VersionUtils.getPreviousVersion();
+        if (previous.before(Version.CURRENT.minimumIndexCompatibilityVersion()) ) {
+            // Can happen when bumping majors: 8.0 is only compat back to 7.0, but that's not released yet
+            // In this case, ignore what's released and just find that latest version before current
+            previous = VersionUtils.allVersions().stream()
+                .filter(v -> v.before(Version.CURRENT))
+                .max(Version::compareTo)
+                .get();
+        }
         createPlugin(
                 "fake",
                 VersionUtils.randomVersionBetween(
                         random(),
                         Version.CURRENT.minimumIndexCompatibilityVersion(),
-                        VersionUtils.getPreviousVersion()));
+                        previous));
         removePlugin("fake", home, randomBoolean());
         assertThat(Files.exists(env.pluginsFile().resolve("fake")), equalTo(false));
         assertRemoveCleaned(env);
diff --git a/docs/Versions.asciidoc b/docs/Versions.asciidoc
index 8a446bf037a12..89d0be877b839 100644
--- a/docs/Versions.asciidoc
+++ b/docs/Versions.asciidoc
@@ -1,5 +1,5 @@
-:version:               7.0.0-alpha2
-:major-version:         7.x
+:version:               8.0.0-alpha1
+:major-version:         8.x
 :lucene_version:        8.0.0
 :lucene_version_path:   8_0_0
 :branch:                master
diff --git a/docs/reference/ml/apis/put-datafeed.asciidoc b/docs/reference/ml/apis/put-datafeed.asciidoc
index 18c611e97cac1..05e02ce3615df 100644
--- a/docs/reference/ml/apis/put-datafeed.asciidoc
+++ b/docs/reference/ml/apis/put-datafeed.asciidoc
@@ -19,6 +19,11 @@ Instantiates a {dfeed}.
 You must create a job before you create a {dfeed}.  You can associate only one
 {dfeed} to each job.
 
+IMPORTANT:  You must use {kib} or this API to create a {dfeed}. Do not put a {dfeed}
+            directly to the `.ml-config` index using the Elasticsearch index API.
+            If {es} {security-features} are enabled, do not give users `write`
+            privileges on the `.ml-config` index.
+
 
 ==== Path Parameters
 
diff --git a/docs/reference/ml/apis/put-job.asciidoc b/docs/reference/ml/apis/put-job.asciidoc
index 4abeebee3e47a..e3d80c276dc55 100644
--- a/docs/reference/ml/apis/put-job.asciidoc
+++ b/docs/reference/ml/apis/put-job.asciidoc
@@ -12,7 +12,13 @@ Instantiates a job.
 
 `PUT _ml/anomaly_detectors/<job_id>`
 
-//===== Description
+===== Description
+
+IMPORTANT: You must use {kib} or this API to create a {ml} job. Do not put a job
+            directly to the `.ml-config` index using the Elasticsearch index API.
+            If {es} {security-features} are enabled, do not give users `write`
+            privileges on the `.ml-config` index.
+
 
 ==== Path Parameters
 
diff --git a/qa/full-cluster-restart/src/test/java/org/elasticsearch/upgrades/FullClusterRestartIT.java b/qa/full-cluster-restart/src/test/java/org/elasticsearch/upgrades/FullClusterRestartIT.java
index 9740ff4222d7e..c6713a2907e33 100644
--- a/qa/full-cluster-restart/src/test/java/org/elasticsearch/upgrades/FullClusterRestartIT.java
+++ b/qa/full-cluster-restart/src/test/java/org/elasticsearch/upgrades/FullClusterRestartIT.java
@@ -38,6 +38,7 @@
 import org.elasticsearch.common.xcontent.support.XContentMapValues;
 import org.elasticsearch.rest.action.document.RestBulkAction;
 import org.elasticsearch.rest.action.document.RestGetAction;
+import org.elasticsearch.rest.action.document.RestIndexAction;
 import org.elasticsearch.rest.action.document.RestUpdateAction;
 import org.elasticsearch.rest.action.search.RestExplainAction;
 import org.elasticsearch.test.NotEqualMessageBuilder;
@@ -80,15 +81,20 @@
  */
 public class FullClusterRestartIT extends AbstractFullClusterRestartTestCase {
     private final boolean supportsLenientBooleans = getOldClusterVersion().before(Version.V_6_0_0_alpha1);
-    private static final Version VERSION_5_1_0_UNRELEASED = Version.fromString("5.1.0");
 
     private String index;
+    private String type;
 
     @Before
     public void setIndex() throws IOException {
         index = getTestName().toLowerCase(Locale.ROOT);
     }
 
+    @Before
+    public void setType() {
+        type = getOldClusterVersion().before(Version.V_6_7_0) ? "doc" : "_doc";
+    }
+
     public void testSearch() throws Exception {
         int count;
         if (isRunningAgainstOldCluster()) {
@@ -102,7 +108,9 @@ public void testSearch() throws Exception {
             }
             {
                 mappingsAndSettings.startObject("mappings");
-                mappingsAndSettings.startObject("doc");
+                if (isRunningAgainstAncientCluster()) {
+                    mappingsAndSettings.startObject(type);
+                }
                 mappingsAndSettings.startObject("properties");
                 {
                     mappingsAndSettings.startObject("string");
@@ -121,7 +129,9 @@ public void testSearch() throws Exception {
                     mappingsAndSettings.endObject();
                 }
                 mappingsAndSettings.endObject();
-                mappingsAndSettings.endObject();
+                if (isRunningAgainstAncientCluster()) {
+                    mappingsAndSettings.endObject();
+                }
                 mappingsAndSettings.endObject();
             }
             mappingsAndSettings.endObject();
@@ -135,17 +145,20 @@ public void testSearch() throws Exception {
             count = randomIntBetween(2000, 3000);
             byte[] randomByteArray = new byte[16];
             random().nextBytes(randomByteArray);
-            indexRandomDocuments(count, true, true, i -> {
-                return JsonXContent.contentBuilder().startObject()
-                .field("string", randomAlphaOfLength(10))
-                .field("int", randomInt(100))
-                .field("float", randomFloat())
-                // be sure to create a "proper" boolean (True, False) for the first document so that automapping is correct
-                .field("bool", i > 0 && supportsLenientBooleans ? randomLenientBoolean() : randomBoolean())
-                .field("field.with.dots", randomAlphaOfLength(10))
-                .field("binary", Base64.getEncoder().encodeToString(randomByteArray))
-                .endObject();
-            });
+            indexRandomDocuments(
+                    count,
+                    true,
+                    true,
+                    i -> JsonXContent.contentBuilder().startObject()
+                            .field("string", randomAlphaOfLength(10))
+                            .field("int", randomInt(100))
+                            .field("float", randomFloat())
+                            // be sure to create a "proper" boolean (True, False) for the first document so that automapping is correct
+                            .field("bool", i > 0 && supportsLenientBooleans ? randomLenientBoolean() : randomBoolean())
+                            .field("field.with.dots", randomAlphaOfLength(10))
+                            .field("binary", Base64.getEncoder().encodeToString(randomByteArray))
+                            .endObject()
+            );
             refresh();
         } else {
             count = countOfIndexedRandomDocuments();
@@ -155,7 +168,7 @@ public void testSearch() throws Exception {
         assertBasicSearchWorks(count);
         assertAllSearchWorks(count);
         assertBasicAggregationWorks();
-        assertRealtimeGetWorks();
+        assertRealtimeGetWorks(type);
         assertStoredBinaryFields(count);
     }
 
@@ -171,7 +184,9 @@ public void testNewReplicasWork() throws Exception {
             }
             {
                 mappingsAndSettings.startObject("mappings");
-                mappingsAndSettings.startObject("doc");
+                if (isRunningAgainstAncientCluster()) {
+                    mappingsAndSettings.startObject(type);
+                }
                 mappingsAndSettings.startObject("properties");
                 {
                     mappingsAndSettings.startObject("field");
@@ -179,7 +194,9 @@ public void testNewReplicasWork() throws Exception {
                     mappingsAndSettings.endObject();
                 }
                 mappingsAndSettings.endObject();
-                mappingsAndSettings.endObject();
+                if (isRunningAgainstAncientCluster()) {
+                    mappingsAndSettings.endObject();
+                }
                 mappingsAndSettings.endObject();
             }
             mappingsAndSettings.endObject();
@@ -191,11 +208,8 @@ public void testNewReplicasWork() throws Exception {
             client().performRequest(createIndex);
 
             int numDocs = randomIntBetween(2000, 3000);
-            indexRandomDocuments(numDocs, true, false, i -> {
-                return JsonXContent.contentBuilder().startObject()
-                    .field("field", "value")
-                    .endObject();
-            });
+            indexRandomDocuments(
+                    numDocs, true, false, i -> JsonXContent.contentBuilder().startObject().field("field", "value").endObject());
             logger.info("Refreshing [{}]", index);
             client().performRequest(new Request("POST", "/" + index + "/_refresh"));
         } else {
@@ -225,76 +239,6 @@ public void testNewReplicasWork() throws Exception {
         }
     }
 
-    /**
-     * Search on an alias that contains illegal characters that would prevent it from being created after 5.1.0. It should still be
-     * search-able though.
-     */
-    public void testAliasWithBadName() throws Exception {
-        assumeTrue("Can only test bad alias name if old cluster is on 5.1.0 or before",
-            getOldClusterVersion().before(VERSION_5_1_0_UNRELEASED));
-
-        int count;
-        if (isRunningAgainstOldCluster()) {
-            XContentBuilder mappingsAndSettings = jsonBuilder();
-            mappingsAndSettings.startObject();
-            {
-                mappingsAndSettings.startObject("settings");
-                mappingsAndSettings.field("number_of_shards", 1);
-                mappingsAndSettings.field("number_of_replicas", 0);
-                mappingsAndSettings.endObject();
-            }
-            {
-                mappingsAndSettings.startObject("mappings");
-                mappingsAndSettings.startObject("doc");
-                mappingsAndSettings.startObject("properties");
-                {
-                    mappingsAndSettings.startObject("key");
-                    mappingsAndSettings.field("type", "keyword");
-                    mappingsAndSettings.endObject();
-                }
-                mappingsAndSettings.endObject();
-                mappingsAndSettings.endObject();
-                mappingsAndSettings.endObject();
-            }
-            mappingsAndSettings.endObject();
-            Request createIndex = new Request("PUT", "/" + index);
-            createIndex.setJsonEntity(Strings.toString(mappingsAndSettings));
-            client().performRequest(createIndex);
-
-            String aliasName = "%23" + index; // %23 == #
-            client().performRequest(new Request("PUT", "/" + index + "/_alias/" + aliasName));
-            Response response = client().performRequest(new Request("HEAD", "/" + index + "/_alias/" + aliasName));
-            assertEquals(200, response.getStatusLine().getStatusCode());
-
-            count = randomIntBetween(32, 128);
-            indexRandomDocuments(count, true, true, i -> {
-                return JsonXContent.contentBuilder().startObject()
-                    .field("key", "value")
-                    .endObject();
-            });
-            refresh();
-        } else {
-            count = countOfIndexedRandomDocuments();
-        }
-
-        Request request = new Request("GET", "/_cluster/state");
-        request.addParameter("metric", "metadata");
-        logger.error("clusterState=" + entityAsMap(client().performRequest(request)));
-        // We can read from the alias just like we can read from the index.
-        String aliasName = "%23" + index; // %23 == #
-        Map<String, Object> searchRsp = entityAsMap(client().performRequest(new Request("GET", "/" + aliasName + "/_search")));
-        int totalHits = extractTotalHits(searchRsp);
-        assertEquals(count, totalHits);
-        if (isRunningAgainstOldCluster() == false) {
-            // We can remove the alias.
-            Response response = client().performRequest(new Request("DELETE", "/" + index + "/_alias/" + aliasName));
-            assertEquals(200, response.getStatusLine().getStatusCode());
-            // and check that it is gone:
-            response = client().performRequest(new Request("HEAD", "/" + index + "/_alias/" + aliasName));
-            assertEquals(404, response.getStatusLine().getStatusCode());
-        }
-    }
-
     public void testClusterState() throws Exception {
         if (isRunningAgainstOldCluster()) {
             XContentBuilder mappingsAndSettings = jsonBuilder();
@@ -348,31 +292,45 @@ public void testShrink() throws IOException {
             mappingsAndSettings.startObject();
             {
                 mappingsAndSettings.startObject("mappings");
-                mappingsAndSettings.startObject("doc");
-                mappingsAndSettings.startObject("properties");
                 {
-                    mappingsAndSettings.startObject("field");
-                    mappingsAndSettings.field("type", "text");
+                    if (isRunningAgainstAncientCluster()) {
+                        mappingsAndSettings.startObject(type);
+                    }
+                    mappingsAndSettings.startObject("properties");
+                    {
+                        mappingsAndSettings.startObject("field");
+                        {
+                            mappingsAndSettings.field("type", "text");
+                        }
+                        mappingsAndSettings.endObject();
+                    }
                     mappingsAndSettings.endObject();
+                    if (isRunningAgainstAncientCluster()) {
+                        mappingsAndSettings.endObject();
+                    }
                 }
                 mappingsAndSettings.endObject();
-                mappingsAndSettings.endObject();
-                mappingsAndSettings.endObject();
+                if (isRunningAgainstAncientCluster() == false) {
+                    // the default number of shards is now one so we have to set the number of shards to be more than one explicitly
+                    mappingsAndSettings.startObject("settings");
+                    {
+                        mappingsAndSettings.field("index.number_of_shards", 5);
+                    }
+                    mappingsAndSettings.endObject();
+                }
             }
             mappingsAndSettings.endObject();
             Request createIndex = new Request("PUT", "/" + index);
             createIndex.setJsonEntity(Strings.toString(mappingsAndSettings));
             RequestOptions.Builder options = createIndex.getOptions().toBuilder();
             options.setWarningsHandler(WarningsHandler.PERMISSIVE);
+            expectWarnings(RestIndexAction.TYPES_DEPRECATION_MESSAGE);
             createIndex.setOptions(options);
             client().performRequest(createIndex);
 
             numDocs = randomIntBetween(512, 1024);
-            indexRandomDocuments(numDocs, true, true, i -> {
-                return JsonXContent.contentBuilder().startObject()
-                    .field("field", "value")
-                    .endObject();
-            });
+            indexRandomDocuments(
+                    numDocs, true, true, i -> JsonXContent.contentBuilder().startObject().field("field", "value").endObject());
 
             ensureGreen(index); // wait for source index to be available on both nodes before starting shrink
 
@@ -381,9 +339,7 @@ public void testShrink() throws IOException {
             client().performRequest(updateSettingsRequest);
 
             Request shrinkIndexRequest = new Request("PUT", "/" + index + "/_shrink/" + shrunkenIndex);
-            if (getOldClusterVersion().onOrAfter(Version.V_6_4_0)) {
-                shrinkIndexRequest.addParameter("copy_settings", "true");
-            }
+
             shrinkIndexRequest.setJsonEntity("{\"settings\": {\"index.number_of_shards\": 1}}");
             client().performRequest(shrinkIndexRequest);
 
@@ -419,16 +375,30 @@ public void testShrinkAfterUpgrade() throws IOException {
             mappingsAndSettings.startObject();
             {
                 mappingsAndSettings.startObject("mappings");
-                mappingsAndSettings.startObject("doc");
-                mappingsAndSettings.startObject("properties");
                 {
-                    mappingsAndSettings.startObject("field");
-                    mappingsAndSettings.field("type", "text");
+                    if (isRunningAgainstAncientCluster()) {
+                        mappingsAndSettings.startObject(type);
+                    }
+                    mappingsAndSettings.startObject("properties");
+                    {
+                        mappingsAndSettings.startObject("field");
+                        {
+                            mappingsAndSettings.field("type", "text");
+                        }
+                        mappingsAndSettings.endObject();
+                    }
                     mappingsAndSettings.endObject();
+                    if (isRunningAgainstAncientCluster()) {
+                        mappingsAndSettings.endObject();
+                    }
                 }
                 mappingsAndSettings.endObject();
-                mappingsAndSettings.endObject();
-                mappingsAndSettings.endObject();
+                if (isRunningAgainstAncientCluster() == false) {
+                    // the default number of shards is now one so we have to set the number of shards to be more than one explicitly
+                    mappingsAndSettings.startObject("settings");
+                    mappingsAndSettings.field("index.number_of_shards", 5);
+                    mappingsAndSettings.endObject();
+                }
             }
             mappingsAndSettings.endObject();
             Request createIndex = new Request("PUT", "/" + index);
@@ -439,11 +409,12 @@ public void testShrinkAfterUpgrade() throws IOException {
             client().performRequest(createIndex);
 
             numDocs = randomIntBetween(512, 1024);
-            indexRandomDocuments(numDocs, true, true, i -> {
-                return JsonXContent.contentBuilder().startObject()
-                    .field("field", "value")
-                    .endObject();
-            });
+            indexRandomDocuments(
+                    numDocs,
+                    true,
+                    true,
+                    i -> JsonXContent.contentBuilder().startObject().field("field", "value").endObject()
+            );
         } else {
             ensureGreen(index); // wait for source index to be available on both nodes before starting shrink
 
@@ -510,7 +481,7 @@ public void testRollover() throws IOException {
             bulk.append("{\"index\":{}}\n");
             bulk.append("{\"test\":\"test\"}\n");
         }
-        Request bulkRequest = new Request("POST", "/" + index + "_write/doc/_bulk");
+        Request bulkRequest = new Request("POST", "/" + index + "_write/" + type + "/_bulk");
         bulkRequest.setJsonEntity(bulk.toString());
         bulkRequest.addParameter("refresh", "");
         bulkRequest.setOptions(expectWarnings(RestBulkAction.TYPES_DEPRECATION_MESSAGE));
@@ -633,7 +604,7 @@ void assertBasicAggregationWorks() throws IOException {
         assertTotalHits(termsCount, boolTerms);
     }
 
-    void assertRealtimeGetWorks() throws IOException {
+    void assertRealtimeGetWorks(final String typeName) throws IOException {
         Request disableAutoRefresh = new Request("PUT", "/" + index + "/_settings");
         disableAutoRefresh.setJsonEntity("{ \"index\": { \"refresh_interval\" : -1 }}");
         client().performRequest(disableAutoRefresh);
@@ -644,13 +615,15 @@ void assertRealtimeGetWorks() throws IOException {
         Map<?, ?> hit = (Map<?, ?>) ((List<?>)(XContentMapValues.extractValue("hits.hits", searchResponse))).get(0);
         String docId = (String) hit.get("_id");
 
-        Request updateRequest = new Request("POST", "/" + index + "/doc/" + docId + "/_update");
+        Request updateRequest = new Request("POST", "/" + index + "/" + typeName + "/" + docId + "/_update");
         updateRequest.setOptions(expectWarnings(RestUpdateAction.TYPES_DEPRECATION_MESSAGE));
         updateRequest.setJsonEntity("{ \"doc\" : { \"foo\": \"bar\"}}");
         client().performRequest(updateRequest);
 
-        Request getRequest = new Request("GET", "/" + index + "/doc/" + docId);
-        getRequest.setOptions(expectWarnings(RestGetAction.TYPES_DEPRECATION_MESSAGE));
+        Request getRequest = new Request("GET", "/" + index + "/" + typeName + "/" + docId);
+        if (getOldClusterVersion().before(Version.V_6_7_0)) {
+            getRequest.setOptions(expectWarnings(RestGetAction.TYPES_DEPRECATION_MESSAGE));
+        }
         Map<String, Object> getRsp = entityAsMap(client().performRequest(getRequest));
         Map<?, ?> source = (Map<?, ?>) getRsp.get("_source");
         assertTrue("doc does not contain 'foo' key: " + source, source.containsKey("foo"));
@@ -689,7 +662,7 @@ static void assertNoFailures(Map<?, ?> response) {
 
     void assertTotalHits(int expectedTotalHits, Map<?, ?> response) {
         int actualTotalHits = extractTotalHits(response);
-        assertEquals(expectedTotalHits, actualTotalHits);
+        assertEquals(response.toString(), expectedTotalHits, actualTotalHits);
     }
 
     int extractTotalHits(Map<?, ?> response) {
@@ -704,7 +677,7 @@ int extractTotalHits(Map<?, ?> response) {
      * Tests that a single document survives. Super basic smoke test.
      */
     public void testSingleDoc() throws IOException {
-        String docLocation = "/" + index + "/doc/1";
+        String docLocation = "/" + index + "/" + type + "/1";
         String doc = "{\"test\": \"test\"}";
 
         if (isRunningAgainstOldCluster()) {
@@ -715,7 +688,9 @@ public void testSingleDoc() throws IOException {
 
 
         Request request = new Request("GET", docLocation);
-        request.setOptions(expectWarnings(RestGetAction.TYPES_DEPRECATION_MESSAGE));
+        if (getOldClusterVersion().before(Version.V_6_7_0)) {
+            request.setOptions(expectWarnings(RestGetAction.TYPES_DEPRECATION_MESSAGE));
+        }
         assertThat(toStr(client().performRequest(request)), containsString(doc));
     }
 
@@ -779,8 +754,12 @@ public void testRecovery() throws Exception {
             }
             if (shouldHaveTranslog) {
                 // Update a few documents so we are sure to have a translog
-                indexRandomDocuments(count / 10, false /* Flushing here would invalidate the whole thing....*/, false,
-                    i -> jsonBuilder().startObject().field("field", "value").endObject());
+                indexRandomDocuments(
+                        count / 10,
+                        false, // flushing here would invalidate the whole thing
+                        false,
+                        i -> jsonBuilder().startObject().field("field", "value").endObject()
+                );
             }
             saveInfoDocument("should_have_translog", Boolean.toString(shouldHaveTranslog));
         } else {
@@ -791,6 +770,7 @@ public void testRecovery() throws Exception {
         // Count the documents in the index to make sure we have as many as we put there
         Request countRequest = new Request("GET", "/" + index + "/_search");
         countRequest.addParameter("size", "0");
+        refresh();
         Map<String, Object> countResponse = entityAsMap(client().performRequest(countRequest));
         assertTotalHits(count, countResponse);
 
@@ -863,7 +843,7 @@ public void testRecovery() throws Exception {
      */
     public void testSnapshotRestore() throws IOException {
         int count;
-        if (isRunningAgainstOldCluster()) {
+        if (isRunningAgainstOldCluster() && getOldClusterVersion().major < 8) {
             // Create the index
             count = between(200, 300);
             indexRandomDocuments(count, true, true, i -> jsonBuilder().startObject().field("field", "value").endObject());
@@ -894,13 +874,19 @@ public void testSnapshotRestore() throws IOException {
         }
         templateBuilder.endObject();
         templateBuilder.startObject("mappings"); {
-            templateBuilder.startObject("doc"); {
-                templateBuilder.startObject("_source"); {
+            if (isRunningAgainstAncientCluster()) {
+                templateBuilder.startObject(type);
+            }
+            {
+                templateBuilder.startObject("_source");
+                {
                     templateBuilder.field("enabled", true);
                 }
                 templateBuilder.endObject();
             }
-            templateBuilder.endObject();
+            if (isRunningAgainstAncientCluster()) {
+                templateBuilder.endObject();
+            }
         }
         templateBuilder.endObject();
         templateBuilder.startObject("aliases"); {
@@ -921,8 +907,8 @@ public void testSnapshotRestore() throws IOException {
         createTemplateRequest.setJsonEntity(Strings.toString(templateBuilder));
 
         // In 7.0, type names are no longer expected by default in put index template requests.
-        // We therefore use the deprecated typed APIs when running against the current version.
-        if (isRunningAgainstOldCluster() == false) {
+        // We therefore use the deprecated typed APIs when running against the current version, but testing with a pre-7 version
+        if (isRunningAgainstOldCluster() == false && getOldClusterVersion().major < 7) {
             createTemplateRequest.addParameter(INCLUDE_TYPE_NAME_PARAMETER, "true");
         }
         createTemplateRequest.setOptions(allowTypeRemovalWarnings());
@@ -1016,12 +1002,13 @@ public void testSoftDeletes() throws Exception {
             int numDocs = between(10, 100);
             for (int i = 0; i < numDocs; i++) {
                 String doc = Strings.toString(JsonXContent.contentBuilder().startObject().field("field", "v1").endObject());
-                Request request = new Request("POST", "/" + index + "/doc/" + i);
+                Request request = new Request("POST", "/" + index + "/" + type + "/" + i);
+                if (isRunningAgainstAncientCluster() == false) {
+                    request.setOptions(expectWarnings(RestIndexAction.TYPES_DEPRECATION_MESSAGE));
+                }
                 request.setJsonEntity(doc);
                 client().performRequest(request);
-                if (rarely()) {
-                    refresh();
-                }
+                refresh();
             }
             client().performRequest(new Request("POST", "/" + index + "/_flush"));
             int liveDocs = numDocs;
@@ -1029,11 +1016,11 @@ public void testSoftDeletes() throws Exception {
             for (int i = 0; i < numDocs; i++) {
                 if (randomBoolean()) {
                     String doc = Strings.toString(JsonXContent.contentBuilder().startObject().field("field", "v2").endObject());
-                    Request request = new Request("POST", "/" + index + "/doc/" + i);
+                    Request request = new Request("POST", "/" + index + "/" + type + "/" + i);
                     request.setJsonEntity(doc);
                     client().performRequest(request);
                 } else if (randomBoolean()) {
-                    client().performRequest(new Request("DELETE", "/" + index + "/doc/" + i));
+                    client().performRequest(new Request("DELETE", "/" + index + "/" + type + "/" + i));
                     liveDocs--;
                 }
             }
@@ -1046,7 +1033,7 @@ public void testSoftDeletes() throws Exception {
         }
     }
 
-    private void checkSnapshot(String snapshotName, int count, Version tookOnVersion) throws IOException {
+    private void checkSnapshot(final String snapshotName, final int count, final Version tookOnVersion) throws IOException {
         // Check the snapshot metadata, especially the version
         Request listSnapshotRequest = new Request("GET", "/_snapshot/repo/" + snapshotName);
         Map<String, Object> listSnapshotResponse = entityAsMap(client().performRequest(listSnapshotRequest));
@@ -1103,7 +1090,7 @@ && getOldClusterVersion().onOrAfter(Version.V_6_1_0) && getOldClusterVersion().b
             bulk.append("{\"index\":{\"_id\":\"").append(count + i).append("\"}}\n");
             bulk.append("{\"test\":\"test\"}\n");
         }
-        Request writeToRestoredRequest = new Request("POST", "/restored_" + index + "/doc/_bulk");
+        Request writeToRestoredRequest = new Request("POST", "/restored_" + index + "/" + type + "/_bulk");
         writeToRestoredRequest.addParameter("refresh", "true");
         writeToRestoredRequest.setJsonEntity(bulk.toString());
         writeToRestoredRequest.setOptions(expectWarnings(RestBulkAction.TYPES_DEPRECATION_MESSAGE));
@@ -1132,7 +1119,7 @@ && getOldClusterVersion().onOrAfter(Version.V_6_1_0) && getOldClusterVersion().b
 
         // In 7.0, type names are no longer returned by default in get index template requests.
         // We therefore use the deprecated typed APIs when running against the current version.
-        if (isRunningAgainstOldCluster() == false) {
+        if (isRunningAgainstAncientCluster() == false) {
             getTemplateRequest.addParameter(INCLUDE_TYPE_NAME_PARAMETER, "true");
         }
         getTemplateRequest.setOptions(allowTypeRemovalWarnings());
@@ -1145,7 +1132,14 @@ && getOldClusterVersion().onOrAfter(Version.V_6_1_0) && getOldClusterVersion().b
             expectedTemplate.put("index_patterns", singletonList("evil_*"));
         }
         expectedTemplate.put("settings", singletonMap("index", singletonMap("number_of_shards", "1")));
-        expectedTemplate.put("mappings", singletonMap("doc", singletonMap("_source", singletonMap("enabled", true))));
+        // We don't have the type in the response starting with 7.0, but we won't have it on old cluster after upgrade
+        // either so look at the response to figure out the correct assertions
+        if (isTypeInTemplateResponse(getTemplateResponse)) {
+            expectedTemplate.put("mappings", singletonMap(type, singletonMap("_source", singletonMap("enabled", true))));
+        } else {
+            expectedTemplate.put("mappings", singletonMap("_source", singletonMap("enabled", true)));
+        }
+
         expectedTemplate.put("order", 0);
         Map<String, Object> aliases = new HashMap<>();
         aliases.put("alias1", emptyMap());
@@ -1155,18 +1149,33 @@ && getOldClusterVersion().onOrAfter(Version.V_6_1_0) && getOldClusterVersion().b
         if (false == expectedTemplate.equals(getTemplateResponse)) {
             NotEqualMessageBuilder builder = new NotEqualMessageBuilder();
             builder.compareMaps(getTemplateResponse, expectedTemplate);
+            logger.info("expected: {}\nactual:{}", expectedTemplate, getTemplateResponse);
             fail("template doesn't match:\n" + builder.toString());
         }
     }
 
+    @SuppressWarnings("unchecked")
+    private boolean isTypeInTemplateResponse(Map<String, Object> getTemplateResponse) {
+        return ( (Map<String, Object>) (
+            (Map<String, Object>) getTemplateResponse.getOrDefault("test_template", emptyMap())
+        ).get("mappings")).get("_source") == null;
+    }
+
     // TODO tests for upgrades after shrink. We've had trouble with shrink in the past.
 
-    private void indexRandomDocuments(int count, boolean flushAllowed, boolean saveInfo,
-                                      CheckedFunction<Integer, XContentBuilder, IOException> docSupplier) throws IOException {
+    private void indexRandomDocuments(
+            final int count,
+            final boolean flushAllowed,
+            final boolean saveInfo,
+            final CheckedFunction<Integer, XContentBuilder, IOException> docSupplier)
+            throws IOException {
         logger.info("Indexing {} random documents", count);
         for (int i = 0; i < count; i++) {
             logger.debug("Indexing document [{}]", i);
-            Request createDocument = new Request("POST", "/" + index + "/doc/" + i);
+            Request createDocument = new Request("POST", "/" + index + "/" + type + "/" + i);
+            if (isRunningAgainstAncientCluster() == false) {
+                createDocument.setOptions(expectWarnings(RestBulkAction.TYPES_DEPRECATION_MESSAGE));
+            }
             createDocument.setJsonEntity(Strings.toString(docSupplier.apply(i)));
             client().performRequest(createDocument);
             if (rarely()) {
@@ -1191,16 +1200,21 @@ private void saveInfoDocument(String type, String value) throws IOException {
         infoDoc.field("value", value);
         infoDoc.endObject();
         // Only create the first version so we know how many documents are created when the index is first created
-        Request request = new Request("PUT", "/info/doc/" + index + "_" + type);
+        Request request = new Request("PUT", "/info/" + this.type + "/" + index + "_" + type);
         request.addParameter("op_type", "create");
         request.setJsonEntity(Strings.toString(infoDoc));
+        if (isRunningAgainstAncientCluster() == false) {
+            request.setOptions(expectWarnings(RestIndexAction.TYPES_DEPRECATION_MESSAGE));
+        }
         client().performRequest(request);
     }
 
     private String loadInfoDocument(String type) throws IOException {
-        Request request = new Request("GET", "/info/doc/" + index + "_" + type);
+        Request request = new Request("GET", "/info/" + this.type + "/" + index + "_" + type);
         request.addParameter("filter_path", "_source");
-        request.setOptions(expectWarnings(RestGetAction.TYPES_DEPRECATION_MESSAGE));
+        if (isRunningAgainstAncientCluster()) {
+            request.setOptions(expectWarnings(RestGetAction.TYPES_DEPRECATION_MESSAGE));
+        }
         String doc = toStr(client().performRequest(request));
         Matcher m = Pattern.compile("\"value\":\"(.+)\"").matcher(doc);
         assertTrue(doc, m.find());
diff --git a/qa/full-cluster-restart/src/test/java/org/elasticsearch/upgrades/QueryBuilderBWCIT.java b/qa/full-cluster-restart/src/test/java/org/elasticsearch/upgrades/QueryBuilderBWCIT.java
index f22b1b44c0763..d6cc9f078e0ed 100644
--- a/qa/full-cluster-restart/src/test/java/org/elasticsearch/upgrades/QueryBuilderBWCIT.java
+++ b/qa/full-cluster-restart/src/test/java/org/elasticsearch/upgrades/QueryBuilderBWCIT.java
@@ -20,6 +20,7 @@
 package org.elasticsearch.upgrades;
 
 import org.apache.http.util.EntityUtils;
+import org.elasticsearch.Version;
 import org.elasticsearch.client.Request;
 import org.elasticsearch.client.RequestOptions;
 import org.elasticsearch.client.Response;
@@ -145,6 +146,7 @@ private static void addCandidate(String querySource, QueryBuilder expectedQb) {
     }
 
     public void testQueryBuilderBWC() throws Exception {
+        final String type = getOldClusterVersion().before(Version.V_7_0_0) ? "doc" : "_doc";
         String index = "queries";
         if (isRunningAgainstOldCluster()) {
             XContentBuilder mappingsAndSettings = jsonBuilder();
@@ -157,7 +159,9 @@ public void testQueryBuilderBWC() throws Exception {
             }
             {
                 mappingsAndSettings.startObject("mappings");
-                mappingsAndSettings.startObject("doc");
+                if (isRunningAgainstAncientCluster()) {
+                    mappingsAndSettings.startObject(type);
+                }
                 mappingsAndSettings.startObject("properties");
                 {
                     mappingsAndSettings.startObject("query");
@@ -176,7 +180,9 @@ public void testQueryBuilderBWC() throws Exception {
                 }
                 mappingsAndSettings.endObject();
                 mappingsAndSettings.endObject();
-                mappingsAndSettings.endObject();
+                if (isRunningAgainstAncientCluster()) {
+                    mappingsAndSettings.endObject();
+                }
             }
             mappingsAndSettings.endObject();
             Request request = new Request("PUT", "/" + index);
@@ -188,7 +194,7 @@ public void testQueryBuilderBWC() throws Exception {
             assertEquals(200, rsp.getStatusLine().getStatusCode());
 
             for (int i = 0; i < CANDIDATES.size(); i++) {
-                request = new Request("PUT", "/" + index + "/doc/" + Integer.toString(i));
+                request = new Request("PUT", "/" + index + "/" + type + "/" + Integer.toString(i));
                 request.setJsonEntity((String) CANDIDATES.get(i)[0]);
                 rsp = client().performRequest(request);
                 assertEquals(201, rsp.getStatusLine().getStatusCode());
diff --git a/qa/rolling-upgrade/src/test/java/org/elasticsearch/upgrades/IndexingIT.java b/qa/rolling-upgrade/src/test/java/org/elasticsearch/upgrades/IndexingIT.java
index c80218c50ebe9..96ebaedadce93 100644
--- a/qa/rolling-upgrade/src/test/java/org/elasticsearch/upgrades/IndexingIT.java
+++ b/qa/rolling-upgrade/src/test/java/org/elasticsearch/upgrades/IndexingIT.java
@@ -19,20 +19,15 @@
 package org.elasticsearch.upgrades;
 
 import org.apache.http.util.EntityUtils;
-import org.elasticsearch.common.Booleans;
-import org.elasticsearch.common.Strings;
-import org.elasticsearch.common.xcontent.XContentBuilder;
-import org.elasticsearch.rest.action.document.RestBulkAction;
-import org.elasticsearch.Version;
 import org.elasticsearch.client.Request;
 import org.elasticsearch.client.Response;
+import org.elasticsearch.common.Booleans;
+import org.elasticsearch.rest.action.document.RestBulkAction;
 
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 
-import static org.elasticsearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.elasticsearch.rest.action.search.RestSearchAction.TOTAL_HITS_AS_INT_PARAM;
-import static org.hamcrest.Matchers.equalTo;
 
 /**
  * Basic test that indexed documents survive the rolling restart. See
@@ -68,26 +63,6 @@ public void testIndexing() throws IOException {
         }
 
         if (CLUSTER_TYPE == ClusterType.OLD) {
-            {
-                Version minimumIndexCompatibilityVersion = Version.CURRENT.minimumIndexCompatibilityVersion();
-                assertThat("this branch is not needed if we aren't compatible with 6.0",
-                        minimumIndexCompatibilityVersion.onOrBefore(Version.V_6_0_0), equalTo(true));
-                if (minimumIndexCompatibilityVersion.before(Version.V_7_0_0)) {
-                    XContentBuilder template = jsonBuilder();
-                    template.startObject();
-                    {
-                        template.field("index_patterns", "*");
-                        template.startObject("settings");
-                        template.field("number_of_shards", 5);
-                        template.endObject();
-                    }
-                    template.endObject();
-                    Request createTemplate = new Request("PUT", "/_template/template");
-                    createTemplate.setJsonEntity(Strings.toString(template));
-                    client().performRequest(createTemplate);
-                }
-            }
-
             Request createTestIndex = new Request("PUT", "/test_index");
             createTestIndex.setJsonEntity("{\"settings\": {\"index.number_of_replicas\": 0}}");
             client().performRequest(createTestIndex);
diff --git a/qa/rolling-upgrade/src/test/java/org/elasticsearch/upgrades/RecoveryIT.java b/qa/rolling-upgrade/src/test/java/org/elasticsearch/upgrades/RecoveryIT.java
index 3666a64896ae2..295aee8b869ff 100644
--- a/qa/rolling-upgrade/src/test/java/org/elasticsearch/upgrades/RecoveryIT.java
+++ b/qa/rolling-upgrade/src/test/java/org/elasticsearch/upgrades/RecoveryIT.java
@@ -300,7 +300,11 @@ public void testRecoveryWithSoftDeletes() throws Exception {
                 if (randomBoolean()) {
                     indexDocs(index, i, 1); // update
                 } else if (randomBoolean()) {
-                    client().performRequest(new Request("DELETE", index + "/test/" + i));
+                    if (getNodeId(v -> v.onOrAfter(Version.V_7_0_0)) == null) {
+                        client().performRequest(new Request("DELETE", index + "/test/" + i));
+                    } else {
+                        client().performRequest(new Request("DELETE", index + "/_doc/" + i));
+                    }
                 }
             }
         }
diff --git a/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/mixed_cluster/10_basic.yml b/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/mixed_cluster/10_basic.yml
index bd07ee8a58469..375ba12a35621 100644
--- a/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/mixed_cluster/10_basic.yml
+++ b/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/mixed_cluster/10_basic.yml
@@ -67,8 +67,3 @@
   - match: { hits.total: 1 }
   - match: { hits.hits.0._id: q3 }
 
----
-"Index with _all is available":
-  - do:
-      indices.get:
-        index: all-index
diff --git a/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/old_cluster/10_basic.yml b/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/old_cluster/10_basic.yml
index a26a3f8274d99..2672cee7cc78a 100644
--- a/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/old_cluster/10_basic.yml
+++ b/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/old_cluster/10_basic.yml
@@ -200,19 +200,3 @@
         wait_for_completion: true
         task_id: $task
 
----
-"Create an index with _all explicitly disabled":
-  - skip:
-      features: warnings
-  - do:
-      warnings:
-        - "[_all] is deprecated in 6.0+ and will be removed in 7.0. As a replacement, you can use [copy_to] on mapping fields to create your own catch all field."
-      indices.create:
-        index: all-index
-        body:
-          mappings:
-            _all:
-              enabled: false
-            properties:
-              field:
-                type: text
diff --git a/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/upgraded_cluster/10_basic.yml b/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/upgraded_cluster/10_basic.yml
index 63e67652127e9..78a4aac867d8f 100644
--- a/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/upgraded_cluster/10_basic.yml
+++ b/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/upgraded_cluster/10_basic.yml
@@ -125,17 +125,4 @@
         task_id: $task_id
   - match: { task.headers.X-Opaque-Id: "Reindexing Again" }
 
----
-"Index with _all is available":
-  - do:
-      indices.get:
-        index: all-index
-
-  - do:
-      indices.get_mapping:
-        include_type_name: false
-        index: all-index
-
-  - is_true: all-index.mappings._all
-  - match: { all-index.mappings._all.enabled: false}
 
diff --git a/qa/verify-version-constants/src/test/java/org/elasticsearch/qa/verify_version_constants/VerifyVersionConstantsIT.java b/qa/verify-version-constants/src/test/java/org/elasticsearch/qa/verify_version_constants/VerifyVersionConstantsIT.java
index 56297eaab8857..bba6b4a8aa27f 100644
--- a/qa/verify-version-constants/src/test/java/org/elasticsearch/qa/verify_version_constants/VerifyVersionConstantsIT.java
+++ b/qa/verify-version-constants/src/test/java/org/elasticsearch/qa/verify_version_constants/VerifyVersionConstantsIT.java
@@ -37,7 +37,7 @@ public void testLuceneVersionConstant() throws IOException, ParseException {
         assertThat(response.getStatusLine().getStatusCode(), equalTo(200));
         final ObjectPath objectPath = ObjectPath.createFromResponse(response);
         final String elasticsearchVersionString = objectPath.evaluate("version.number").toString();
-        final Version elasticsearchVersion = Version.fromString(elasticsearchVersionString);
+        final Version elasticsearchVersion = Version.fromString(elasticsearchVersionString.replace("-SNAPSHOT", ""));
         final String luceneVersionString = objectPath.evaluate("version.lucene_version").toString();
         final org.apache.lucene.util.Version luceneVersion = org.apache.lucene.util.Version.parse(luceneVersionString);
         assertThat(elasticsearchVersion.luceneVersion, equalTo(luceneVersion));
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/api/indices.shrink.json b/rest-api-spec/src/main/resources/rest-api-spec/api/indices.shrink.json
index f92421b79ae91..5ef943eacba6c 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/api/indices.shrink.json
+++ b/rest-api-spec/src/main/resources/rest-api-spec/api/indices.shrink.json
@@ -18,10 +18,6 @@
         }
       },
       "params": {
-        "copy_settings": {
-          "type" : "boolean",
-          "description" : "whether or not to copy settings from the source index (defaults to false)"
-        },
         "timeout": {
           "type" : "time",
           "description" : "Explicit operation timeout"
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/api/indices.split.json b/rest-api-spec/src/main/resources/rest-api-spec/api/indices.split.json
index 2c14fced28c36..a79fa7b708269 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/api/indices.split.json
+++ b/rest-api-spec/src/main/resources/rest-api-spec/api/indices.split.json
@@ -18,10 +18,6 @@
         }
       },
       "params": {
-        "copy_settings": {
-          "type" : "boolean",
-          "description" : "whether or not to copy settings from the source index (defaults to false)"
-        },
         "timeout": {
           "type" : "time",
           "description" : "Explicit operation timeout"
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/test/indices.shrink/30_copy_settings.yml b/rest-api-spec/src/main/resources/rest-api-spec/test/indices.shrink/30_copy_settings.yml
index 8c4c84c4be152..3add4b100d812 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/test/indices.shrink/30_copy_settings.yml
+++ b/rest-api-spec/src/main/resources/rest-api-spec/test/indices.shrink/30_copy_settings.yml
@@ -43,13 +43,10 @@
         target: "copy-settings-target"
         wait_for_active_shards: 1
         master_timeout: 10s
-        copy_settings: true
         body:
           settings:
             index.number_of_replicas: 0
             index.merge.scheduler.max_thread_count: 2
-      warnings:
-        - "parameter [copy_settings] is deprecated and will be removed in 8.0.0"
 
   - do:
       cluster.health:
@@ -64,42 +61,3 @@
   - match: { copy-settings-target.settings.index.merge.scheduler.max_thread_count: "2" }
   - match: { copy-settings-target.settings.index.blocks.write: "true" }
   - match: { copy-settings-target.settings.index.routing.allocation.include._id: $master }
-
-  # now we do a actual shrink and copy settings (by default)
-  - do:
-      indices.shrink:
-        index: "source"
-        target: "default-copy-settings-target"
-        wait_for_active_shards: 1
-        master_timeout: 10s
-        body:
-          settings:
-            index.number_of_replicas: 0
-            index.merge.scheduler.max_thread_count: 2
-
-  - do:
-      cluster.health:
-        wait_for_status: green
-
-  - do:
-      indices.get_settings:
-        index: "default-copy-settings-target"
-
-  # settings should be copied
-  - match: { default-copy-settings-target.settings.index.merge.scheduler.max_merge_count: "4" }
-  - match: { default-copy-settings-target.settings.index.merge.scheduler.max_thread_count: "2" }
-  - match: { default-copy-settings-target.settings.index.blocks.write: "true" }
-  - match: { default-copy-settings-target.settings.index.routing.allocation.include._id: $master }
-
-  # now we do a actual shrink and try to set no copy settings
-  - do:
-      catch: /illegal_argument_exception/
-      indices.shrink:
-        index: "source"
-        target: "explicit-no-copy-settings-target"
-        wait_for_active_shards: 1
-        master_timeout: 10s
-        copy_settings: false
-        body:
-          settings:
-            index.number_of_replicas: 0
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/test/indices.split/30_copy_settings.yml b/rest-api-spec/src/main/resources/rest-api-spec/test/indices.split/30_copy_settings.yml
index 90d4080e46379..8cf932b1c1159 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/test/indices.split/30_copy_settings.yml
+++ b/rest-api-spec/src/main/resources/rest-api-spec/test/indices.split/30_copy_settings.yml
@@ -44,15 +44,11 @@
         target: "copy-settings-target"
         wait_for_active_shards: 1
         master_timeout: 10s
-        copy_settings: true
         body:
           settings:
             index.number_of_replicas: 0
             index.number_of_shards: 2
             index.merge.scheduler.max_thread_count: 2
-      warnings:
-        - "parameter [copy_settings] is deprecated and will be removed in 8.0.0"
-
 
   - do:
       cluster.health:
@@ -67,42 +63,3 @@
   - match: { copy-settings-target.settings.index.merge.scheduler.max_thread_count: "2" }
   - match: { copy-settings-target.settings.index.blocks.write: "true" }
   - match: { copy-settings-target.settings.index.routing.allocation.include._id: $master }
-
-  # now we do a actual shrink and copy settings (by default)
-  - do:
-      indices.split:
-        index: "source"
-        target: "default-copy-settings-target"
-        wait_for_active_shards: 1
-        master_timeout: 10s
-        body:
-          settings:
-            index.number_of_replicas: 0
-            index.number_of_shards: 2
-            index.merge.scheduler.max_thread_count: 2
-
-  - do:
-      cluster.health:
-        wait_for_status: green
-
-  - do:
-      indices.get_settings:
-        index: "default-copy-settings-target"
-
-  # settings should be copied
-  - match: { default-copy-settings-target.settings.index.merge.scheduler.max_merge_count: "4" }
-  - match: { default-copy-settings-target.settings.index.merge.scheduler.max_thread_count: "2" }
-  - match: { default-copy-settings-target.settings.index.blocks.write: "true" }
-  - match: { default-copy-settings-target.settings.index.routing.allocation.include._id: $master }
-
-  - do:
-      catch: /illegal_argument_exception/
-      indices.split:
-        index: "source"
-        target: "explicit-no-copy-settings-target"
-        wait_for_active_shards: 1
-        master_timeout: 10s
-        copy_settings: false
-        body:
-          settings:
-            index.number_of_replicas: 0
diff --git a/server/src/main/java/org/elasticsearch/Version.java b/server/src/main/java/org/elasticsearch/Version.java
index e520d714bb931..c02062b2bbd63 100644
--- a/server/src/main/java/org/elasticsearch/Version.java
+++ b/server/src/main/java/org/elasticsearch/Version.java
@@ -124,7 +124,11 @@ public class Version implements Comparable<Version>, ToXContentFragment {
     public static final Version V_6_7_0 = new Version(V_6_7_0_ID, org.apache.lucene.util.Version.LUCENE_7_7_0);
     public static final int V_7_0_0_ID = 7000099;
     public static final Version V_7_0_0 = new Version(V_7_0_0_ID, org.apache.lucene.util.Version.LUCENE_8_0_0);
-    public static final Version CURRENT = V_7_0_0;
+    public static final int V_7_1_0_ID = 7010099;
+    public static final Version V_7_1_0 = new Version(V_7_1_0_ID, org.apache.lucene.util.Version.LUCENE_8_0_0);
+    public static final int V_8_0_0_ID = 8000099;
+    public static final Version V_8_0_0 = new Version(V_8_0_0_ID, org.apache.lucene.util.Version.LUCENE_8_0_0);
+    public static final Version CURRENT = V_8_0_0;
 
 
     static {
@@ -138,6 +142,10 @@ public static Version readVersion(StreamInput in) throws IOException {
 
     public static Version fromId(int id) {
         switch (id) {
+            case V_8_0_0_ID:
+                return V_8_0_0;
+            case V_7_1_0_ID:
+                return V_7_1_0;
             case V_7_0_0_ID:
                 return V_7_0_0;
             case V_6_7_0_ID:
diff --git a/server/src/main/java/org/elasticsearch/action/resync/ResyncReplicationRequest.java b/server/src/main/java/org/elasticsearch/action/resync/ResyncReplicationRequest.java
index a53766af7cf52..2ec0e9200d436 100644
--- a/server/src/main/java/org/elasticsearch/action/resync/ResyncReplicationRequest.java
+++ b/server/src/main/java/org/elasticsearch/action/resync/ResyncReplicationRequest.java
@@ -66,7 +66,8 @@ public Translog.Operation[] getOperations() {
 
     @Override
     public void readFrom(final StreamInput in) throws IOException {
-        assert Version.CURRENT.major <= 7;
+        //  TODO: https://github.com/elastic/elasticsearch/issues/38556
+        //assert Version.CURRENT.major <= 7;
         if (in.getVersion().equals(Version.V_6_0_0)) {
             /*
              * Resync replication request serialization was broken in 6.0.0 due to the elements of the stream not being prefixed with a
diff --git a/server/src/main/java/org/elasticsearch/cluster/coordination/Coordinator.java b/server/src/main/java/org/elasticsearch/cluster/coordination/Coordinator.java
index 6843534107178..9eed4600738b0 100644
--- a/server/src/main/java/org/elasticsearch/cluster/coordination/Coordinator.java
+++ b/server/src/main/java/org/elasticsearch/cluster/coordination/Coordinator.java
@@ -127,7 +127,6 @@ public class Coordinator extends AbstractLifecycleComponent implements Discovery
     private long maxTermSeen;
     private final Reconfigurator reconfigurator;
     private final ClusterBootstrapService clusterBootstrapService;
-    private final DiscoveryUpgradeService discoveryUpgradeService;
     private final LagDetector lagDetector;
     private final ClusterFormationFailureHelper clusterFormationFailureHelper;
 
@@ -169,8 +168,6 @@ public Coordinator(String nodeName, Settings settings, ClusterSettings clusterSe
         this.reconfigurator = new Reconfigurator(settings, clusterSettings);
         this.clusterBootstrapService = new ClusterBootstrapService(settings, transportService, this::getFoundPeers,
             this::isInitialConfigurationSet, this::setInitialConfiguration);
-        this.discoveryUpgradeService = new DiscoveryUpgradeService(settings, transportService,
-            this::isInitialConfigurationSet, joinHelper, peerFinder::getFoundPeers, this::setInitialConfiguration);
         this.lagDetector = new LagDetector(settings, transportService.getThreadPool(), n -> removeNode(n, "lagging"),
             transportService::getLocalNode);
         this.clusterFormationFailureHelper = new ClusterFormationFailureHelper(settings, this::getClusterFormationState,
@@ -508,10 +505,6 @@ void becomeCandidate(String method) {
             peerFinder.activate(coordinationState.get().getLastAcceptedState().nodes());
             clusterFormationFailureHelper.start();
 
-            if (getCurrentTerm() == ZEN1_BWC_TERM) {
-                discoveryUpgradeService.activate(lastKnownLeader, coordinationState.get().getLastAcceptedState());
-            }
-
             leaderChecker.setCurrentNodes(DiscoveryNodes.EMPTY_NODES);
             leaderChecker.updateLeader(null);
 
@@ -543,7 +536,6 @@ void becomeLeader(String method) {
 
         lastKnownLeader = Optional.of(getLocalNode());
         peerFinder.deactivate(getLocalNode());
-        discoveryUpgradeService.deactivate();
         clusterFormationFailureHelper.stop();
         closePrevotingAndElectionScheduler();
         preVoteCollector.update(getPreVoteResponse(), getLocalNode());
@@ -575,7 +567,6 @@ void becomeFollower(String method, DiscoveryNode leaderNode) {
 
         lastKnownLeader = Optional.of(leaderNode);
         peerFinder.deactivate(leaderNode);
-        discoveryUpgradeService.deactivate();
         clusterFormationFailureHelper.stop();
         closePrevotingAndElectionScheduler();
         cancelActivePublication("become follower: " + method);
diff --git a/server/src/main/java/org/elasticsearch/cluster/coordination/DiscoveryUpgradeService.java b/server/src/main/java/org/elasticsearch/cluster/coordination/DiscoveryUpgradeService.java
deleted file mode 100644
index 3bf5fa225a934..0000000000000
--- a/server/src/main/java/org/elasticsearch/cluster/coordination/DiscoveryUpgradeService.java
+++ /dev/null
@@ -1,347 +0,0 @@
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-package org.elasticsearch.cluster.coordination;
-
-import org.apache.logging.log4j.LogManager;
-import org.apache.logging.log4j.Logger;
-import org.apache.logging.log4j.message.ParameterizedMessage;
-import org.elasticsearch.Version;
-import org.elasticsearch.action.ActionListener;
-import org.elasticsearch.cluster.ClusterName;
-import org.elasticsearch.cluster.ClusterState;
-import org.elasticsearch.cluster.coordination.CoordinationMetaData.VotingConfiguration;
-import org.elasticsearch.cluster.node.DiscoveryNode;
-import org.elasticsearch.common.Nullable;
-import org.elasticsearch.common.io.stream.StreamInput;
-import org.elasticsearch.common.settings.Setting;
-import org.elasticsearch.common.settings.Settings;
-import org.elasticsearch.common.unit.TimeValue;
-import org.elasticsearch.common.util.concurrent.CountDown;
-import org.elasticsearch.discovery.zen.ElectMasterService;
-import org.elasticsearch.discovery.zen.ElectMasterService.MasterCandidate;
-import org.elasticsearch.discovery.zen.UnicastZenPing;
-import org.elasticsearch.discovery.zen.UnicastZenPing.UnicastPingRequest;
-import org.elasticsearch.discovery.zen.UnicastZenPing.UnicastPingResponse;
-import org.elasticsearch.discovery.zen.ZenPing.PingResponse;
-import org.elasticsearch.threadpool.ThreadPool;
-import org.elasticsearch.threadpool.ThreadPool.Names;
-import org.elasticsearch.transport.TransportException;
-import org.elasticsearch.transport.TransportRequestOptions;
-import org.elasticsearch.transport.TransportResponseHandler;
-import org.elasticsearch.transport.TransportService;
-
-import java.io.IOException;
-import java.util.HashSet;
-import java.util.Iterator;
-import java.util.Optional;
-import java.util.Set;
-import java.util.function.BooleanSupplier;
-import java.util.function.Consumer;
-import java.util.function.Supplier;
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
-import java.util.stream.StreamSupport;
-
-import static java.lang.Math.max;
-import static org.elasticsearch.cluster.ClusterName.CLUSTER_NAME_SETTING;
-import static org.elasticsearch.cluster.ClusterState.UNKNOWN_VERSION;
-import static org.elasticsearch.common.util.concurrent.ConcurrentCollections.newConcurrentSet;
-import static org.elasticsearch.discovery.zen.ElectMasterService.DISCOVERY_ZEN_MINIMUM_MASTER_NODES_SETTING;
-import static org.elasticsearch.discovery.zen.ZenDiscovery.PING_TIMEOUT_SETTING;
-
-/**
- * Deals with rolling upgrades of the cluster coordination layer. In mixed clusters we prefer to elect the older nodes, but
- * when the last old node shuts down then as long as there are enough new nodes we can assume that they form the whole cluster and
- * define them as the initial configuration.
- */
-public class DiscoveryUpgradeService {
-
-    private static Logger logger = LogManager.getLogger(DiscoveryUpgradeService.class);
-
-    // how long to wait after activation before attempting to join a master or perform a bootstrap upgrade
-    public static final Setting<TimeValue> BWC_PING_TIMEOUT_SETTING =
-        Setting.timeSetting("discovery.zen.bwc_ping_timeout",
-            PING_TIMEOUT_SETTING, TimeValue.timeValueMillis(1), Setting.Property.NodeScope, Setting.Property.Deprecated);
-
-    // whether to try and bootstrap all the discovered Zen2 nodes when the last Zen1 node leaves the cluster.
-    public static final Setting<Boolean> ENABLE_UNSAFE_BOOTSTRAPPING_ON_UPGRADE_SETTING =
-        Setting.boolSetting("discovery.zen.unsafe_rolling_upgrades_enabled", true, Setting.Property.NodeScope, Setting.Property.Deprecated);
-
-    /**
-     * Dummy {@link ElectMasterService} that is only used to choose the best 6.x master from the discovered nodes, ignoring the
-     * `minimum_master_nodes` setting.
-     */
-    private static final ElectMasterService electMasterService = new ElectMasterService(Settings.EMPTY);
-
-    private final TransportService transportService;
-    private final BooleanSupplier isBootstrappedSupplier;
-    private final JoinHelper joinHelper;
-    private final Supplier<Iterable<DiscoveryNode>> peersSupplier;
-    private final Consumer<VotingConfiguration> initialConfigurationConsumer;
-    private final TimeValue bwcPingTimeout;
-    private final boolean enableUnsafeBootstrappingOnUpgrade;
-    private final ClusterName clusterName;
-
-    @Nullable // null if no active joining round
-    private volatile JoiningRound joiningRound;
-
-    public DiscoveryUpgradeService(Settings settings, TransportService transportService,
-                                   BooleanSupplier isBootstrappedSupplier, JoinHelper joinHelper,
-                                   Supplier<Iterable<DiscoveryNode>> peersSupplier,
-                                   Consumer<VotingConfiguration> initialConfigurationConsumer) {
-        assert Version.CURRENT.major == Version.V_6_6_0.major + 1 : "remove this service once unsafe upgrades are no longer needed";
-        this.transportService = transportService;
-        this.isBootstrappedSupplier = isBootstrappedSupplier;
-        this.joinHelper = joinHelper;
-        this.peersSupplier = peersSupplier;
-        this.initialConfigurationConsumer = initialConfigurationConsumer;
-        this.bwcPingTimeout = BWC_PING_TIMEOUT_SETTING.get(settings);
-        this.enableUnsafeBootstrappingOnUpgrade = ENABLE_UNSAFE_BOOTSTRAPPING_ON_UPGRADE_SETTING.get(settings);
-        this.clusterName = CLUSTER_NAME_SETTING.get(settings);
-    }
-
-    public void activate(Optional<DiscoveryNode> lastKnownLeader, ClusterState lastAcceptedClusterState) {
-        // called under coordinator mutex
-
-        if (isBootstrappedSupplier.getAsBoolean()) {
-            return;
-        }
-
-        assert lastKnownLeader.isPresent() == false || Coordinator.isZen1Node(lastKnownLeader.get()) : lastKnownLeader;
-        // if there was a leader and it's not a old node then we must have been bootstrapped
-
-        final Settings dynamicSettings = lastAcceptedClusterState.metaData().settings();
-        final int minimumMasterNodes = DISCOVERY_ZEN_MINIMUM_MASTER_NODES_SETTING.exists(dynamicSettings)
-            ? DISCOVERY_ZEN_MINIMUM_MASTER_NODES_SETTING.get(dynamicSettings)
-            : lastAcceptedClusterState.getMinimumMasterNodesOnPublishingMaster();
-
-        assert joiningRound == null : joiningRound;
-        final Set<String> knownMasterNodeIds = new HashSet<>();
-        lastAcceptedClusterState.nodes().getMasterNodes().forEach(c -> knownMasterNodeIds.add(c.key));
-
-        joiningRound
-            = new JoiningRound(enableUnsafeBootstrappingOnUpgrade && lastKnownLeader.isPresent(), minimumMasterNodes, knownMasterNodeIds);
-        joiningRound.scheduleNextAttempt();
-    }
-
-    public void deactivate() {
-        // called under coordinator mutex
-        joiningRound = null;
-    }
-
-    /**
-     * Waits for some number of calls to {@link ListenableCountDown#countDown()} and then notifies a listener. The listener
-     * is only ever notified once, whether successful or not.
-     */
-    private static class ListenableCountDown {
-        private final CountDown countDown;
-        private final ActionListener<Void> listener;
-
-        ListenableCountDown(int count, ActionListener<Void> listener) {
-            this.countDown = new CountDown(count);
-            this.listener = listener;
-        }
-
-        void onFailure(Exception e) {
-            if (countDown.fastForward()) {
-                listener.onFailure(e);
-            }
-        }
-
-        void countDown() {
-            if (countDown.countDown()) {
-                listener.onResponse(null);
-            }
-        }
-    }
-
-    private class JoiningRound {
-        private final boolean upgrading;
-        private final int minimumMasterNodes;
-        private final Set<String> knownMasterNodeIds;
-
-        JoiningRound(boolean upgrading, int minimumMasterNodes, Set<String> knownMasterNodeIds) {
-            this.upgrading = upgrading;
-            this.minimumMasterNodes = minimumMasterNodes;
-            this.knownMasterNodeIds = knownMasterNodeIds;
-        }
-
-        private boolean isRunning() {
-            return joiningRound == this && isBootstrappedSupplier.getAsBoolean() == false;
-        }
-
-        private boolean canBootstrap(Set<DiscoveryNode> discoveryNodes) {
-            return upgrading && minimumMasterNodes <= discoveryNodes.stream().filter(DiscoveryNode::isMasterNode).count();
-        }
-
-        void scheduleNextAttempt() {
-            if (isRunning() == false) {
-                return;
-            }
-
-            final ThreadPool threadPool = transportService.getThreadPool();
-            threadPool.scheduleUnlessShuttingDown(bwcPingTimeout, Names.SAME, new Runnable() {
-
-                @Override
-                public void run() {
-                    if (isRunning() == false) {
-                        return;
-                    }
-
-                    final Set<DiscoveryNode> discoveryNodes = Stream.concat(StreamSupport.stream(peersSupplier.get().spliterator(), false),
-                        Stream.of(transportService.getLocalNode())).filter(DiscoveryNode::isMasterNode).collect(Collectors.toSet());
-
-                    // this set of nodes is reasonably fresh - the PeerFinder cleans up nodes to which the transport service is not
-                    // connected each time it wakes up (every second by default)
-
-                    logger.debug("upgrading={}, minimumMasterNodes={}, nodes={}", upgrading, minimumMasterNodes, discoveryNodes);
-
-                    if (discoveryNodes.stream().anyMatch(Coordinator::isZen1Node)) {
-                        electBestOldMaster(discoveryNodes);
-                    } else if (canBootstrap(discoveryNodes)) {
-                        // no Zen1 nodes found, but the last-known master was a Zen1 node, so this is a rolling upgrade
-                        transportService.getThreadPool().generic().execute(() -> {
-                            try {
-                                Set<String> nodeIds = new HashSet<>();
-                                discoveryNodes.forEach(n -> nodeIds.add(n.getId()));
-
-                                final Iterator<String> knownNodeIdIterator = knownMasterNodeIds.iterator();
-                                while (nodeIds.size() < 2 * minimumMasterNodes - 1 && knownNodeIdIterator.hasNext()) {
-                                    nodeIds.add(knownNodeIdIterator.next());
-                                }
-
-                                final VotingConfiguration votingConfiguration = new VotingConfiguration(nodeIds);
-                                assert votingConfiguration.hasQuorum(
-                                    discoveryNodes.stream().map(DiscoveryNode::getId).collect(Collectors.toList()));
-                                assert 2 * minimumMasterNodes - 2 <= nodeIds.size() : nodeIds + " too small for " + minimumMasterNodes;
-
-                                initialConfigurationConsumer.accept(votingConfiguration);
-                            } catch (Exception e) {
-                                logger.debug("exception during bootstrapping upgrade, retrying", e);
-                            } finally {
-                                scheduleNextAttempt();
-                            }
-                        });
-                    } else {
-                        scheduleNextAttempt();
-                    }
-                }
-
-                /**
-                 * Ping all the old discovered masters one more time to obtain their cluster state versions, and then vote for the best one.
-                 * @param discoveryNodes The master nodes (old and new).
-                 */
-                private void electBestOldMaster(Set<DiscoveryNode> discoveryNodes) {
-                    final Set<MasterCandidate> masterCandidates = newConcurrentSet();
-                    final ListenableCountDown listenableCountDown
-                        = new ListenableCountDown(discoveryNodes.size(), new ActionListener<Void>() {
-
-                        @Override
-                        public void onResponse(Void value) {
-                            assert masterCandidates.size() == discoveryNodes.size()
-                                : masterCandidates + " does not match " + discoveryNodes;
-
-                            // TODO we shouldn't elect a master with a version that's older than ours
-                            // If the only Zen1 nodes left are stale, and we can bootstrap, maybe we should bootstrap?
-                            // Do we ever need to elect a freshly-started Zen1 node?
-                            if (isRunning()) {
-                                final MasterCandidate electedMaster = electMasterService.electMaster(masterCandidates);
-                                logger.debug("elected {}, sending join", electedMaster);
-                                joinHelper.sendJoinRequest(electedMaster.getNode(), Optional.empty(),
-                                    JoiningRound.this::scheduleNextAttempt);
-                            }
-                        }
-
-                        @Override
-                        public void onFailure(Exception e) {
-                            scheduleNextAttempt();
-                        }
-                    });
-
-                    boolean foundOldMaster = false;
-                    for (final DiscoveryNode discoveryNode : discoveryNodes) {
-                        assert discoveryNode.isMasterNode() : discoveryNode;
-                        if (Coordinator.isZen1Node(discoveryNode)) {
-                            foundOldMaster = true;
-                            transportService.sendRequest(discoveryNode, UnicastZenPing.ACTION_NAME,
-                                new UnicastPingRequest(0, TimeValue.ZERO,
-                                    new PingResponse(createDiscoveryNodeWithImpossiblyHighId(transportService.getLocalNode()),
-                                        null, clusterName, UNKNOWN_VERSION)),
-                                TransportRequestOptions.builder().withTimeout(bwcPingTimeout).build(),
-                                new TransportResponseHandler<UnicastPingResponse>() {
-                                    @Override
-                                    public void handleResponse(UnicastPingResponse response) {
-                                        long clusterStateVersion = UNKNOWN_VERSION;
-                                        for (PingResponse pingResponse : response.pingResponses) {
-                                            if (discoveryNode.equals(pingResponse.node())) {
-                                                clusterStateVersion
-                                                    = max(clusterStateVersion, pingResponse.getClusterStateVersion());
-                                            }
-                                        }
-                                        masterCandidates.add(new MasterCandidate(discoveryNode, clusterStateVersion));
-                                        listenableCountDown.countDown();
-                                    }
-
-                                    @Override
-                                    public void handleException(TransportException exp) {
-                                        logger.debug(
-                                            new ParameterizedMessage("unexpected exception when pinging {}", discoveryNode), exp);
-                                        listenableCountDown.onFailure(exp);
-                                    }
-
-                                    @Override
-                                    public String executor() {
-                                        return Names.SAME;
-                                    }
-
-                                    @Override
-                                    public UnicastPingResponse read(StreamInput in) throws IOException {
-                                        return new UnicastPingResponse(in);
-                                    }
-                                });
-
-                        } else {
-                            masterCandidates.add(
-                                new MasterCandidate(createDiscoveryNodeWithImpossiblyHighId(discoveryNode), UNKNOWN_VERSION));
-                            listenableCountDown.countDown();
-                        }
-                    }
-                    assert foundOldMaster;
-                }
-
-                @Override
-                public String toString() {
-                    return "discovery upgrade service retry";
-                }
-            });
-        }
-    }
-
-    /**
-     * Pre-7.0 nodes select the best master by comparing their IDs (as strings) and selecting the lowest one amongst those nodes with
-     * the best cluster state version. We want 7.0+ nodes to participate in these elections in a mixed cluster but never to win one, so
-     * we lie and claim to have an impossible ID that compares above all genuine IDs.
-     */
-    public static DiscoveryNode createDiscoveryNodeWithImpossiblyHighId(DiscoveryNode node) {
-        // IDs are base-64-encoded UUIDs, which means they use the character set [0-9A-Za-z_-]. The highest character in this set is 'z',
-        // and 'z' < '{', so by starting the ID with '{' we can be sure it's greater. This is terrible.
-        return new DiscoveryNode(node.getName(), "{zen2}" + node.getId(), node.getEphemeralId(), node.getHostName(),
-            node.getHostAddress(), node.getAddress(), node.getAttributes(), node.getRoles(), node.getVersion());
-    }
-}
diff --git a/server/src/main/java/org/elasticsearch/cluster/coordination/PublicationTransportHandler.java b/server/src/main/java/org/elasticsearch/cluster/coordination/PublicationTransportHandler.java
index b0b91cd0980f2..241b9b3f82231 100644
--- a/server/src/main/java/org/elasticsearch/cluster/coordination/PublicationTransportHandler.java
+++ b/server/src/main/java/org/elasticsearch/cluster/coordination/PublicationTransportHandler.java
@@ -93,31 +93,9 @@ public PublicationTransportHandler(TransportService transportService, NamedWrite
         transportService.registerRequestHandler(PUBLISH_STATE_ACTION_NAME, BytesTransportRequest::new, ThreadPool.Names.GENERIC,
             false, false, (request, channel, task) -> channel.sendResponse(handleIncomingPublishRequest(request)));
 
-        transportService.registerRequestHandler(PublishClusterStateAction.SEND_ACTION_NAME, BytesTransportRequest::new,
-            ThreadPool.Names.GENERIC,
-            false, false, (request, channel, task) -> {
-                handleIncomingPublishRequest(request);
-                channel.sendResponse(TransportResponse.Empty.INSTANCE);
-            });
-
         transportService.registerRequestHandler(COMMIT_STATE_ACTION_NAME, ThreadPool.Names.GENERIC, false, false,
             ApplyCommitRequest::new,
             (request, channel, task) -> handleApplyCommit.accept(request, transportCommitCallback(channel)));
-
-        transportService.registerRequestHandler(PublishClusterStateAction.COMMIT_ACTION_NAME,
-            PublishClusterStateAction.CommitClusterStateRequest::new,
-            ThreadPool.Names.GENERIC, false, false,
-            (request, channel, task) -> {
-                final Optional<ClusterState> matchingClusterState = Optional.ofNullable(lastSeenClusterState.get()).filter(
-                    cs -> cs.stateUUID().equals(request.stateUUID));
-                if (matchingClusterState.isPresent() == false) {
-                    throw new IllegalStateException("can't resolve cluster state with uuid" +
-                        " [" + request.stateUUID + "] to commit");
-                }
-                final ApplyCommitRequest applyCommitRequest = new ApplyCommitRequest(matchingClusterState.get().getNodes().getMasterNode(),
-                    matchingClusterState.get().term(), matchingClusterState.get().version());
-                handleApplyCommit.accept(applyCommitRequest, transportCommitCallback(channel));
-            });
     }
 
     private ActionListener<Void> transportCommitCallback(TransportChannel channel) {
diff --git a/server/src/main/java/org/elasticsearch/cluster/metadata/MetaDataCreateIndexService.java b/server/src/main/java/org/elasticsearch/cluster/metadata/MetaDataCreateIndexService.java
index 838b1e2547204..2e18e5aeae50a 100644
--- a/server/src/main/java/org/elasticsearch/cluster/metadata/MetaDataCreateIndexService.java
+++ b/server/src/main/java/org/elasticsearch/cluster/metadata/MetaDataCreateIndexService.java
@@ -590,7 +590,8 @@ public ClusterState execute(ClusterState currentState) throws Exception {
 
         static int getNumberOfShards(final Settings.Builder indexSettingsBuilder) {
             // TODO: this logic can be removed when the current major version is 8
-            assert Version.CURRENT.major == 7;
+            // TODO: https://github.com/elastic/elasticsearch/issues/38556
+            // assert Version.CURRENT.major == 7;
             final int numberOfShards;
             final Version indexVersionCreated =
                     Version.fromId(Integer.parseInt(indexSettingsBuilder.get(IndexMetaData.SETTING_INDEX_VERSION_CREATED.getKey())));
diff --git a/server/src/main/java/org/elasticsearch/common/settings/ClusterSettings.java b/server/src/main/java/org/elasticsearch/common/settings/ClusterSettings.java
index 0ae30c465b26e..61c3dd9adadad 100644
--- a/server/src/main/java/org/elasticsearch/common/settings/ClusterSettings.java
+++ b/server/src/main/java/org/elasticsearch/common/settings/ClusterSettings.java
@@ -35,7 +35,6 @@
 import org.elasticsearch.cluster.coordination.ClusterBootstrapService;
 import org.elasticsearch.cluster.coordination.ClusterFormationFailureHelper;
 import org.elasticsearch.cluster.coordination.Coordinator;
-import org.elasticsearch.cluster.coordination.DiscoveryUpgradeService;
 import org.elasticsearch.cluster.coordination.ElectionSchedulerFactory;
 import org.elasticsearch.cluster.coordination.FollowersChecker;
 import org.elasticsearch.cluster.coordination.JoinHelper;
@@ -67,9 +66,9 @@
 import org.elasticsearch.discovery.DiscoveryModule;
 import org.elasticsearch.discovery.DiscoverySettings;
 import org.elasticsearch.discovery.PeerFinder;
+import org.elasticsearch.discovery.SettingsBasedSeedHostsProvider;
 import org.elasticsearch.discovery.zen.ElectMasterService;
 import org.elasticsearch.discovery.zen.FaultDetection;
-import org.elasticsearch.discovery.SettingsBasedSeedHostsProvider;
 import org.elasticsearch.discovery.zen.UnicastZenPing;
 import org.elasticsearch.discovery.zen.ZenDiscovery;
 import org.elasticsearch.env.Environment;
@@ -493,9 +492,7 @@ public void apply(Settings value, Settings current, Settings previous) {
                     TransportAddVotingConfigExclusionsAction.MAXIMUM_VOTING_CONFIG_EXCLUSIONS_SETTING,
                     ClusterBootstrapService.INITIAL_MASTER_NODES_SETTING,
                     ClusterBootstrapService.UNCONFIGURED_BOOTSTRAP_TIMEOUT_SETTING,
-                    LagDetector.CLUSTER_FOLLOWER_LAG_TIMEOUT_SETTING,
-                    DiscoveryUpgradeService.BWC_PING_TIMEOUT_SETTING,
-                    DiscoveryUpgradeService.ENABLE_UNSAFE_BOOTSTRAPPING_ON_UPGRADE_SETTING
+                    LagDetector.CLUSTER_FOLLOWER_LAG_TIMEOUT_SETTING
             )));
 
     public static List<SettingUpgrader<?>> BUILT_IN_SETTING_UPGRADERS = Collections.unmodifiableList(Arrays.asList(
diff --git a/server/src/main/java/org/elasticsearch/common/time/DateUtils.java b/server/src/main/java/org/elasticsearch/common/time/DateUtils.java
index 20646ae14599a..4235344bd8371 100644
--- a/server/src/main/java/org/elasticsearch/common/time/DateUtils.java
+++ b/server/src/main/java/org/elasticsearch/common/time/DateUtils.java
@@ -23,9 +23,12 @@
 import org.elasticsearch.common.logging.DeprecationLogger;
 import org.joda.time.DateTimeZone;
 
+import java.time.Clock;
+import java.time.Duration;
 import java.time.Instant;
 import java.time.ZoneId;
 import java.time.ZoneOffset;
+import java.time.ZonedDateTime;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
@@ -139,4 +142,18 @@ public static long toMilliSeconds(long nanoSecondsSinceEpoch) {
 
         return nanoSecondsSinceEpoch / 1_000_000;
     }
+
+    /**
+     * Returns the current UTC date-time with milliseconds precision.
+     * In Java 9+ (as opposed to Java 8) the {@code Clock} implementation uses system's best clock implementation (which could mean
+     * that the precision of the clock can be milliseconds, microseconds or nanoseconds), whereas in Java 8
+     * {@code System.currentTimeMillis()} is always used. To account for these differences, this method defines a new {@code Clock}
+     * which will offer a value for {@code ZonedDateTime.now()} set to always have milliseconds precision.
+     *
+     * @return {@link ZonedDateTime} instance for the current date-time with milliseconds precision in UTC
+     */
+    public static ZonedDateTime nowWithMillisResolution() {
+        Clock millisResolutionClock = Clock.tick(Clock.systemUTC(), Duration.ofMillis(1));
+        return ZonedDateTime.now(millisResolutionClock);
+    }
 }
diff --git a/server/src/main/java/org/elasticsearch/discovery/PeerFinder.java b/server/src/main/java/org/elasticsearch/discovery/PeerFinder.java
index 58248b8183d34..839661ca87e8a 100644
--- a/server/src/main/java/org/elasticsearch/discovery/PeerFinder.java
+++ b/server/src/main/java/org/elasticsearch/discovery/PeerFinder.java
@@ -25,8 +25,6 @@
 import org.apache.logging.log4j.message.ParameterizedMessage;
 import org.apache.lucene.util.SetOnce;
 import org.elasticsearch.action.ActionListener;
-import org.elasticsearch.cluster.ClusterName;
-import org.elasticsearch.cluster.ClusterState;
 import org.elasticsearch.cluster.coordination.PeersResponse;
 import org.elasticsearch.cluster.node.DiscoveryNode;
 import org.elasticsearch.cluster.node.DiscoveryNodes;
@@ -37,24 +35,13 @@
 import org.elasticsearch.common.transport.TransportAddress;
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.common.util.concurrent.AbstractRunnable;
-import org.elasticsearch.discovery.zen.UnicastZenPing;
-import org.elasticsearch.discovery.zen.ZenDiscovery;
-import org.elasticsearch.discovery.zen.ZenPing;
-import org.elasticsearch.discovery.zen.ZenPing.PingResponse;
-import org.elasticsearch.tasks.Task;
 import org.elasticsearch.threadpool.ThreadPool.Names;
-import org.elasticsearch.transport.TransportChannel;
 import org.elasticsearch.transport.TransportException;
-import org.elasticsearch.transport.TransportRequest;
-import org.elasticsearch.transport.TransportRequestHandler;
 import org.elasticsearch.transport.TransportRequestOptions;
 import org.elasticsearch.transport.TransportResponseHandler;
 import org.elasticsearch.transport.TransportService;
 
 import java.io.IOException;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
@@ -64,8 +51,6 @@
 import java.util.stream.Collectors;
 
 import static java.util.Collections.emptyList;
-import static org.elasticsearch.cluster.coordination.Coordinator.isZen1Node;
-import static org.elasticsearch.cluster.coordination.DiscoveryUpgradeService.createDiscoveryNodeWithImpossiblyHighId;
 
 public abstract class PeerFinder {
 
@@ -82,8 +67,6 @@ public abstract class PeerFinder {
         Setting.timeSetting("discovery.request_peers_timeout",
             TimeValue.timeValueMillis(3000), TimeValue.timeValueMillis(1), Setting.Property.NodeScope);
 
-    private final Settings settings;
-
     private final TimeValue findPeersInterval;
     private final TimeValue requestPeersTimeout;
 
@@ -101,7 +84,6 @@ public abstract class PeerFinder {
 
     public PeerFinder(Settings settings, TransportService transportService, TransportAddressConnector transportAddressConnector,
                       ConfiguredHostsResolver configuredHostsResolver) {
-        this.settings = settings;
         findPeersInterval = DISCOVERY_FIND_PEERS_INTERVAL_SETTING.get(settings);
         requestPeersTimeout = DISCOVERY_REQUEST_PEERS_TIMEOUT_SETTING.get(settings);
         this.transportService = transportService;
@@ -111,9 +93,6 @@ public PeerFinder(Settings settings, TransportService transportService, Transpor
         transportService.registerRequestHandler(REQUEST_PEERS_ACTION_NAME, Names.GENERIC, false, false,
             PeersRequest::new,
             (request, channel, task) -> channel.sendResponse(handlePeersRequest(request)));
-
-        transportService.registerRequestHandler(UnicastZenPing.ACTION_NAME, Names.GENERIC, false, false,
-            UnicastZenPing.UnicastPingRequest::new, new Zen1UnicastPingRequestHandler());
     }
 
     public void activate(final DiscoveryNodes lastAcceptedNodes) {
@@ -453,36 +432,10 @@ public String executor() {
                     return Names.GENERIC;
                 }
             };
-            final String actionName;
-            final TransportRequest transportRequest;
-            final TransportResponseHandler<?> transportResponseHandler;
-            if (isZen1Node(discoveryNode)) {
-                actionName = UnicastZenPing.ACTION_NAME;
-                transportRequest = new UnicastZenPing.UnicastPingRequest(1, ZenDiscovery.PING_TIMEOUT_SETTING.get(settings),
-                    new ZenPing.PingResponse(createDiscoveryNodeWithImpossiblyHighId(getLocalNode()), null,
-                        ClusterName.CLUSTER_NAME_SETTING.get(settings), ClusterState.UNKNOWN_VERSION));
-                transportResponseHandler = peersResponseHandler.wrap(ucResponse -> {
-                    Optional<DiscoveryNode> optionalMasterNode = Arrays.stream(ucResponse.pingResponses)
-                        .filter(pr -> discoveryNode.equals(pr.node()) && discoveryNode.equals(pr.master()))
-                        .map(ZenPing.PingResponse::node)
-                        .findFirst();
-                    List<DiscoveryNode> discoveredNodes = new ArrayList<>();
-                    if (optionalMasterNode.isPresent() == false) {
-                        Arrays.stream(ucResponse.pingResponses).map(PingResponse::master).filter(Objects::nonNull)
-                            .forEach(discoveredNodes::add);
-                        Arrays.stream(ucResponse.pingResponses).map(PingResponse::node).forEach(discoveredNodes::add);
-                    }
-                    return new PeersResponse(optionalMasterNode, discoveredNodes, 0L);
-                }, UnicastZenPing.UnicastPingResponse::new);
-            } else {
-                actionName = REQUEST_PEERS_ACTION_NAME;
-                transportRequest = new PeersRequest(getLocalNode(), knownNodes);
-                transportResponseHandler = peersResponseHandler;
-            }
-            transportService.sendRequest(discoveryNode, actionName,
-                transportRequest,
+            transportService.sendRequest(discoveryNode, REQUEST_PEERS_ACTION_NAME,
+                new PeersRequest(getLocalNode(), knownNodes),
                 TransportRequestOptions.builder().withTimeout(requestPeersTimeout).build(),
-                transportResponseHandler);
+                peersResponseHandler);
         }
 
         @Override
@@ -494,22 +447,4 @@ public String toString() {
                 '}';
         }
     }
-
-    private class Zen1UnicastPingRequestHandler implements TransportRequestHandler<UnicastZenPing.UnicastPingRequest> {
-        @Override
-        public void messageReceived(UnicastZenPing.UnicastPingRequest request, TransportChannel channel, Task task) throws Exception {
-            final PeersRequest peersRequest = new PeersRequest(request.pingResponse.node(),
-                Optional.ofNullable(request.pingResponse.master()).map(Collections::singletonList).orElse(emptyList()));
-            final PeersResponse peersResponse = handlePeersRequest(peersRequest);
-            final List<ZenPing.PingResponse> pingResponses = new ArrayList<>();
-            final ClusterName clusterName = ClusterName.CLUSTER_NAME_SETTING.get(settings);
-            pingResponses.add(new ZenPing.PingResponse(createDiscoveryNodeWithImpossiblyHighId(transportService.getLocalNode()),
-                peersResponse.getMasterNode().orElse(null),
-                clusterName, ClusterState.UNKNOWN_VERSION));
-            peersResponse.getKnownPeers().forEach(dn -> pingResponses.add(
-                new ZenPing.PingResponse(ZenPing.PingResponse.FAKE_PING_ID,
-                    isZen1Node(dn) ? dn : createDiscoveryNodeWithImpossiblyHighId(dn), null, clusterName, ClusterState.UNKNOWN_VERSION)));
-            channel.sendResponse(new UnicastZenPing.UnicastPingResponse(request.id, pingResponses.toArray(new ZenPing.PingResponse[0])));
-        }
-    }
 }
diff --git a/server/src/main/java/org/elasticsearch/gateway/MetaStateService.java b/server/src/main/java/org/elasticsearch/gateway/MetaStateService.java
index 7bef4d5819e45..d67cdccb9a09b 100644
--- a/server/src/main/java/org/elasticsearch/gateway/MetaStateService.java
+++ b/server/src/main/java/org/elasticsearch/gateway/MetaStateService.java
@@ -21,7 +21,6 @@
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
-import org.elasticsearch.Version;
 import org.elasticsearch.cluster.metadata.IndexMetaData;
 import org.elasticsearch.cluster.metadata.Manifest;
 import org.elasticsearch.cluster.metadata.MetaData;
@@ -118,7 +117,8 @@ private Tuple<Manifest, MetaData> loadFullStateBWC() throws IOException {
 
         if (globalMetaData != null) {
             metaDataBuilder = MetaData.builder(globalMetaData);
-            assert Version.CURRENT.major < 8 : "failed to find manifest file, which is mandatory staring with Elasticsearch version 8.0";
+            // TODO https://github.com/elastic/elasticsearch/issues/38556
+            // assert Version.CURRENT.major < 8 : "failed to find manifest file, which is mandatory staring with Elasticsearch version 8.0";
         } else {
             metaDataBuilder = MetaData.builder();
         }
@@ -127,7 +127,8 @@ private Tuple<Manifest, MetaData> loadFullStateBWC() throws IOException {
             Tuple<IndexMetaData, Long> indexMetaDataAndGeneration =
                     INDEX_META_DATA_FORMAT.loadLatestStateWithGeneration(logger, namedXContentRegistry,
                             nodeEnv.resolveIndexFolder(indexFolderName));
-            assert Version.CURRENT.major < 8 : "failed to find manifest file, which is mandatory staring with Elasticsearch version 8.0";
+            // TODO https://github.com/elastic/elasticsearch/issues/38556
+            // assert Version.CURRENT.major < 8 : "failed to find manifest file, which is mandatory staring with Elasticsearch version 8.0";
             IndexMetaData indexMetaData = indexMetaDataAndGeneration.v1();
             long generation = indexMetaDataAndGeneration.v2();
             if (indexMetaData != null) {
@@ -291,4 +292,4 @@ public void writeGlobalStateAndUpdateManifest(String reason, MetaData metaData)
         writeManifestAndCleanup(reason, manifest);
         cleanupGlobalState(generation);
     }
-}
\ No newline at end of file
+}
diff --git a/server/src/main/java/org/elasticsearch/node/InternalSettingsPreparer.java b/server/src/main/java/org/elasticsearch/node/InternalSettingsPreparer.java
index e0157fff23cfd..b73268d9985b5 100644
--- a/server/src/main/java/org/elasticsearch/node/InternalSettingsPreparer.java
+++ b/server/src/main/java/org/elasticsearch/node/InternalSettingsPreparer.java
@@ -19,6 +19,11 @@
 
 package org.elasticsearch.node;
 
+import org.elasticsearch.cluster.ClusterName;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.settings.SettingsException;
+import org.elasticsearch.env.Environment;
+
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -26,21 +31,11 @@
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
-import java.util.function.Supplier;
 import java.util.function.Function;
-
-import org.elasticsearch.Version;
-import org.elasticsearch.cluster.ClusterName;
-import org.elasticsearch.common.settings.Settings;
-import org.elasticsearch.common.settings.SettingsException;
-import org.elasticsearch.env.Environment;
-import org.elasticsearch.node.Node;
+import java.util.function.Supplier;
 
 public class InternalSettingsPreparer {
 
-    private static final String SECRET_PROMPT_VALUE = "${prompt.secret}";
-    private static final String TEXT_PROMPT_VALUE = "${prompt.text}";
-
     /**
      * Prepares settings for the transport client by gathering all
      * elasticsearch system properties and setting defaults.
@@ -88,7 +83,6 @@ public static Environment prepareEnvironment(Settings input, Map<String, String>
 
         // re-initialize settings now that the config file has been loaded
         initializeSettings(output, input, properties);
-        checkSettingsForTerminalDeprecation(output);
         finalizeSettings(output, defaultNodeName);
 
         environment = new Environment(output.build(), configPath);
@@ -112,25 +106,6 @@ static void initializeSettings(final Settings.Builder output, final Settings inp
         output.replacePropertyPlaceholders();
     }
 
-    /**
-     * Checks all settings values to make sure they do not have the old prompt settings. These were deprecated in 6.0.0.
-     * This check should be removed in 8.0.0.
-     */
-    private static void checkSettingsForTerminalDeprecation(final Settings.Builder output) throws SettingsException {
-        // This method to be removed in 8.0.0, as it was deprecated in 6.0 and removed in 7.0
-        assert Version.CURRENT.major != 8: "Logic pertaining to config driven prompting should be removed";
-        for (String setting : output.keys()) {
-            switch (output.get(setting)) {
-                case SECRET_PROMPT_VALUE:
-                    throw new SettingsException("Config driven secret prompting was deprecated in 6.0.0. Use the keystore" +
-                        " for secure settings.");
-                case TEXT_PROMPT_VALUE:
-                    throw new SettingsException("Config driven text prompting was deprecated in 6.0.0. Use the keystore" +
-                        " for secure settings.");
-            }
-        }
-    }
-
     /**
      * Finish preparing settings by replacing forced settings and any defaults that need to be added.
      */
diff --git a/server/src/main/java/org/elasticsearch/rest/action/admin/indices/RestResizeHandler.java b/server/src/main/java/org/elasticsearch/rest/action/admin/indices/RestResizeHandler.java
index 60c481e59878f..3d0158cf95f0f 100644
--- a/server/src/main/java/org/elasticsearch/rest/action/admin/indices/RestResizeHandler.java
+++ b/server/src/main/java/org/elasticsearch/rest/action/admin/indices/RestResizeHandler.java
@@ -19,15 +19,10 @@
 
 package org.elasticsearch.rest.action.admin.indices;
 
-import org.apache.logging.log4j.Logger;
-import org.apache.logging.log4j.LogManager;
-import org.elasticsearch.Version;
 import org.elasticsearch.action.admin.indices.shrink.ResizeRequest;
 import org.elasticsearch.action.admin.indices.shrink.ResizeType;
 import org.elasticsearch.action.support.ActiveShardCount;
 import org.elasticsearch.client.node.NodeClient;
-import org.elasticsearch.common.Booleans;
-import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.RestController;
@@ -37,8 +32,6 @@
 import java.io.IOException;
 
 public abstract class RestResizeHandler extends BaseRestHandler {
-    private static final Logger logger = LogManager.getLogger(RestResizeHandler.class);
-    private static final DeprecationLogger deprecationLogger = new DeprecationLogger(logger);
 
     RestResizeHandler(final Settings settings) {
         super(settings);
@@ -53,24 +46,6 @@ public abstract class RestResizeHandler extends BaseRestHandler {
     public final RestChannelConsumer prepareRequest(final RestRequest request, final NodeClient client) throws IOException {
         final ResizeRequest resizeRequest = new ResizeRequest(request.param("target"), request.param("index"));
         resizeRequest.setResizeType(getResizeType());
-        // copy_settings should be removed in Elasticsearch 8.0.0; cf. https://github.com/elastic/elasticsearch/issues/28347
-        assert Version.CURRENT.major < 8;
-        final String rawCopySettings = request.param("copy_settings");
-        final Boolean copySettings;
-        if (rawCopySettings == null) {
-            copySettings = resizeRequest.getCopySettings();
-        } else {
-            if (rawCopySettings.isEmpty()) {
-                copySettings = true;
-            } else {
-                copySettings = Booleans.parseBoolean(rawCopySettings);
-                if (copySettings == false) {
-                    throw new IllegalArgumentException("parameter [copy_settings] can not be explicitly set to [false]");
-                }
-            }
-            deprecationLogger.deprecated("parameter [copy_settings] is deprecated and will be removed in 8.0.0");
-        }
-        resizeRequest.setCopySettings(copySettings);
         request.applyContentParser(resizeRequest::fromXContent);
         resizeRequest.timeout(request.paramAsTime("timeout", resizeRequest.timeout()));
         resizeRequest.masterNodeTimeout(request.paramAsTime("master_timeout", resizeRequest.masterNodeTimeout()));
diff --git a/server/src/main/java/org/elasticsearch/transport/RemoteClusterAware.java b/server/src/main/java/org/elasticsearch/transport/RemoteClusterAware.java
index 9b9243b612b74..ff06e59d4f729 100644
--- a/server/src/main/java/org/elasticsearch/transport/RemoteClusterAware.java
+++ b/server/src/main/java/org/elasticsearch/transport/RemoteClusterAware.java
@@ -57,7 +57,8 @@ public abstract class RemoteClusterAware {
 
     static {
         // remove search.remote.* settings in 8.0.0
-        assert Version.CURRENT.major < 8;
+        // TODO https://github.com/elastic/elasticsearch/issues/38556
+        // assert Version.CURRENT.major < 8;
     }
 
     public static final Setting.AffixSetting<List<String>> SEARCH_REMOTE_CLUSTERS_SEEDS =
diff --git a/server/src/main/java/org/elasticsearch/transport/RemoteClusterService.java b/server/src/main/java/org/elasticsearch/transport/RemoteClusterService.java
index 009ee48dd8a99..a126337aa0e54 100644
--- a/server/src/main/java/org/elasticsearch/transport/RemoteClusterService.java
+++ b/server/src/main/java/org/elasticsearch/transport/RemoteClusterService.java
@@ -69,7 +69,8 @@ public final class RemoteClusterService extends RemoteClusterAware implements Cl
 
     static {
         // remove search.remote.* settings in 8.0.0
-        assert Version.CURRENT.major < 8;
+        // TODO
+        // assert Version.CURRENT.major < 8;
     }
 
     public static final Setting<Integer> SEARCH_REMOTE_CONNECTIONS_PER_CLUSTER =
diff --git a/server/src/test/java/org/elasticsearch/VersionTests.java b/server/src/test/java/org/elasticsearch/VersionTests.java
index 08db8dfaf2100..99077cbea70db 100644
--- a/server/src/test/java/org/elasticsearch/VersionTests.java
+++ b/server/src/test/java/org/elasticsearch/VersionTests.java
@@ -367,10 +367,9 @@ public void testIsCompatible() {
                                 () -> new IllegalStateException("expected previous minor version for [" + currentOrNextMajorVersion + "]"));
         final Version previousMinorVersion = VersionUtils.getPreviousMinorVersion();
 
-        assert previousMinorVersion.major == currentOrNextMajorVersion.major
-                || previousMinorVersion.major == lastMinorFromPreviousMajor.major;
-        boolean isCompatible = previousMinorVersion.major == currentOrNextMajorVersion.major
-                || previousMinorVersion.minor == lastMinorFromPreviousMajor.minor;
+        boolean isCompatible =
+                previousMinorVersion.major == currentOrNextMajorVersion.major
+                        || previousMinorVersion.minor == lastMinorFromPreviousMajor.minor;
 
         final String message = String.format(
                 Locale.ROOT,
diff --git a/server/src/test/java/org/elasticsearch/cluster/coordination/DiscoveryUpgradeServiceTests.java b/server/src/test/java/org/elasticsearch/cluster/coordination/DiscoveryUpgradeServiceTests.java
deleted file mode 100644
index 01e9c1403313c..0000000000000
--- a/server/src/test/java/org/elasticsearch/cluster/coordination/DiscoveryUpgradeServiceTests.java
+++ /dev/null
@@ -1,38 +0,0 @@
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-package org.elasticsearch.cluster.coordination;
-
-import org.elasticsearch.Version;
-import org.elasticsearch.cluster.node.DiscoveryNode;
-import org.elasticsearch.common.UUIDs;
-import org.elasticsearch.test.ESTestCase;
-
-import static org.hamcrest.Matchers.containsString;
-import static org.hamcrest.Matchers.lessThan;
-
-public class DiscoveryUpgradeServiceTests extends ESTestCase {
-    public void testCreateDiscoveryNodeWithImpossiblyHighId() {
-        final DiscoveryNode discoveryNode
-            = new DiscoveryNode(UUIDs.randomBase64UUID(random()), buildNewFakeTransportAddress(), Version.CURRENT);
-        final DiscoveryNode fakeNode = DiscoveryUpgradeService.createDiscoveryNodeWithImpossiblyHighId(discoveryNode);
-        assertThat(discoveryNode.getId(), lessThan(fakeNode.getId()));
-        assertThat(UUIDs.randomBase64UUID(random()), lessThan(fakeNode.getId()));
-        assertThat(fakeNode.getId(), containsString(discoveryNode.getId()));
-    }
-}
diff --git a/server/src/test/java/org/elasticsearch/cluster/coordination/Zen1IT.java b/server/src/test/java/org/elasticsearch/cluster/coordination/Zen1IT.java
deleted file mode 100644
index 3ba9f58523d16..0000000000000
--- a/server/src/test/java/org/elasticsearch/cluster/coordination/Zen1IT.java
+++ /dev/null
@@ -1,373 +0,0 @@
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-package org.elasticsearch.cluster.coordination;
-
-import org.elasticsearch.action.admin.cluster.configuration.AddVotingConfigExclusionsAction;
-import org.elasticsearch.action.admin.cluster.configuration.AddVotingConfigExclusionsRequest;
-import org.elasticsearch.action.admin.cluster.configuration.ClearVotingConfigExclusionsAction;
-import org.elasticsearch.action.admin.cluster.configuration.ClearVotingConfigExclusionsRequest;
-import org.elasticsearch.action.admin.cluster.health.ClusterHealthRequest;
-import org.elasticsearch.action.admin.cluster.health.ClusterHealthRequestBuilder;
-import org.elasticsearch.action.admin.cluster.health.ClusterHealthResponse;
-import org.elasticsearch.action.admin.cluster.state.ClusterStateRequest;
-import org.elasticsearch.action.admin.indices.create.CreateIndexRequest;
-import org.elasticsearch.client.Client;
-import org.elasticsearch.client.Requests;
-import org.elasticsearch.cluster.metadata.IndexMetaData;
-import org.elasticsearch.cluster.metadata.Manifest;
-import org.elasticsearch.cluster.routing.UnassignedInfo;
-import org.elasticsearch.cluster.routing.allocation.decider.EnableAllocationDecider.Allocation;
-import org.elasticsearch.common.Priority;
-import org.elasticsearch.common.settings.Settings;
-import org.elasticsearch.common.unit.TimeValue;
-import org.elasticsearch.discovery.Discovery;
-import org.elasticsearch.discovery.DiscoveryModule;
-import org.elasticsearch.discovery.zen.ElectMasterService;
-import org.elasticsearch.env.NodeEnvironment;
-import org.elasticsearch.gateway.MetaStateService;
-import org.elasticsearch.plugins.Plugin;
-import org.elasticsearch.test.ESIntegTestCase;
-import org.elasticsearch.test.InternalTestCluster.RestartCallback;
-import org.elasticsearch.test.transport.MockTransportService;
-import org.elasticsearch.transport.TransportService;
-
-import java.util.Collection;
-import java.util.Collections;
-import java.util.List;
-import java.util.stream.Collectors;
-import java.util.stream.IntStream;
-import java.util.stream.StreamSupport;
-
-import static org.elasticsearch.cluster.coordination.ClusterBootstrapService.INITIAL_MASTER_NODES_SETTING;
-import static org.elasticsearch.cluster.coordination.Coordinator.ZEN1_BWC_TERM;
-import static org.elasticsearch.cluster.coordination.FollowersChecker.FOLLOWER_CHECK_ACTION_NAME;
-import static org.elasticsearch.cluster.coordination.JoinHelper.START_JOIN_ACTION_NAME;
-import static org.elasticsearch.cluster.coordination.PublicationTransportHandler.PUBLISH_STATE_ACTION_NAME;
-import static org.elasticsearch.cluster.routing.allocation.decider.EnableAllocationDecider.CLUSTER_ROUTING_ALLOCATION_ENABLE_SETTING;
-import static org.elasticsearch.cluster.routing.allocation.decider.FilterAllocationDecider.CLUSTER_ROUTING_EXCLUDE_GROUP_SETTING;
-import static org.elasticsearch.node.Node.NODE_NAME_SETTING;
-import static org.elasticsearch.test.InternalTestCluster.REMOVED_MINIMUM_MASTER_NODES;
-import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertAcked;
-import static org.hamcrest.Matchers.equalTo;
-import static org.hamcrest.Matchers.is;
-
-@ESIntegTestCase.ClusterScope(scope = ESIntegTestCase.Scope.TEST, numDataNodes = 0)
-public class Zen1IT extends ESIntegTestCase {
-
-    private static Settings ZEN1_SETTINGS = Coordinator.addZen1Attribute(true, Settings.builder()
-        .put(DiscoveryModule.DISCOVERY_TYPE_SETTING.getKey(), DiscoveryModule.ZEN_DISCOVERY_TYPE)).build();
-
-    private static Settings ZEN2_SETTINGS = Settings.builder()
-        .put(DiscoveryModule.DISCOVERY_TYPE_SETTING.getKey(), DiscoveryModule.ZEN2_DISCOVERY_TYPE)
-        .build();
-
-    protected Collection<Class<? extends Plugin>> nodePlugins() {
-        return Collections.singletonList(MockTransportService.TestPlugin.class);
-    }
-
-    public void testZen2NodesJoiningZen1Cluster() {
-        internalCluster().startNodes(randomIntBetween(1, 3), ZEN1_SETTINGS);
-        internalCluster().startNodes(randomIntBetween(1, 3), ZEN2_SETTINGS);
-        createIndex("test");
-    }
-
-    public void testZen1NodesJoiningZen2Cluster() {
-        internalCluster().startNodes(randomIntBetween(1, 3), ZEN2_SETTINGS);
-        internalCluster().startNodes(randomIntBetween(1, 3), ZEN1_SETTINGS);
-        createIndex("test");
-    }
-
-    public void testMixedClusterDisruption() throws Exception {
-        final List<String> nodes = internalCluster().startNodes(IntStream.range(0, 5)
-            .mapToObj(i -> i < 2 ? ZEN1_SETTINGS : ZEN2_SETTINGS).toArray(Settings[]::new));
-
-        final List<MockTransportService> transportServices = nodes.stream()
-            .map(n -> (MockTransportService) internalCluster().getInstance(TransportService.class, n)).collect(Collectors.toList());
-
-        logger.info("--> disrupting communications");
-
-        // The idea here is to make some of the Zen2 nodes believe the Zen1 nodes have gone away by introducing a network partition, so that
-        // they bootstrap themselves, but keep the Zen1 side of the cluster alive.
-
-        // Set up a bridged network partition with the Zen1 nodes {0,1} on one side, Zen2 nodes {3,4} on the other, and node {2} in both
-        transportServices.get(0).addFailToSendNoConnectRule(transportServices.get(3));
-        transportServices.get(0).addFailToSendNoConnectRule(transportServices.get(4));
-        transportServices.get(1).addFailToSendNoConnectRule(transportServices.get(3));
-        transportServices.get(1).addFailToSendNoConnectRule(transportServices.get(4));
-        transportServices.get(3).addFailToSendNoConnectRule(transportServices.get(0));
-        transportServices.get(3).addFailToSendNoConnectRule(transportServices.get(1));
-        transportServices.get(4).addFailToSendNoConnectRule(transportServices.get(0));
-        transportServices.get(4).addFailToSendNoConnectRule(transportServices.get(1));
-
-        // Nodes 3 and 4 will bootstrap, but we want to keep node 2 as part of the Zen1 cluster, so prevent any messages that might switch
-        // its allegiance
-        transportServices.get(3).addFailToSendNoConnectRule(transportServices.get(2),
-            PUBLISH_STATE_ACTION_NAME, FOLLOWER_CHECK_ACTION_NAME, START_JOIN_ACTION_NAME);
-        transportServices.get(4).addFailToSendNoConnectRule(transportServices.get(2),
-            PUBLISH_STATE_ACTION_NAME, FOLLOWER_CHECK_ACTION_NAME, START_JOIN_ACTION_NAME);
-
-        logger.info("--> waiting for disconnected nodes to be removed");
-        ensureStableCluster(3, nodes.get(0));
-
-        logger.info("--> creating index on Zen1 side");
-        assertAcked(client(nodes.get(0)).admin().indices().create(new CreateIndexRequest("test")).get());
-        assertFalse(client(nodes.get(0)).admin().cluster().health(new ClusterHealthRequest("test")
-            .waitForGreenStatus()).get().isTimedOut());
-
-        logger.info("--> waiting for disconnected nodes to bootstrap themselves");
-        assertBusy(() -> assertTrue(IntStream.range(3, 5)
-            .mapToObj(n -> (Coordinator) internalCluster().getInstance(Discovery.class, nodes.get(n)))
-            .anyMatch(Coordinator::isInitialConfigurationSet)));
-
-        logger.info("--> clearing disruption and waiting for cluster to reform");
-        transportServices.forEach(MockTransportService::clearAllRules);
-
-        ensureStableCluster(5, nodes.get(0));
-        assertFalse(client(nodes.get(0)).admin().cluster().health(new ClusterHealthRequest("test")
-            .waitForGreenStatus()).get().isTimedOut());
-    }
-
-    public void testMixedClusterFormation() throws Exception {
-        final int zen1NodeCount = randomIntBetween(1, 3);
-        final int zen2NodeCount = randomIntBetween(zen1NodeCount == 1 ? 2 : 1, 3);
-        logger.info("starting cluster of [{}] Zen1 nodes and [{}] Zen2 nodes", zen1NodeCount, zen2NodeCount);
-        final List<String> nodes = internalCluster().startNodes(IntStream.range(0, zen1NodeCount + zen2NodeCount)
-            .mapToObj(i -> i < zen1NodeCount ? ZEN1_SETTINGS : ZEN2_SETTINGS).toArray(Settings[]::new));
-
-        createIndex("test",
-            Settings.builder()
-                .put(UnassignedInfo.INDEX_DELAYED_NODE_LEFT_TIMEOUT_SETTING.getKey(), TimeValue.ZERO) // assign shards
-                .put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, zen1NodeCount + zen2NodeCount + randomIntBetween(0, 2)) // causes rebalancing
-                .put(IndexMetaData.SETTING_NUMBER_OF_REPLICAS, 1)
-                .build());
-        ensureGreen("test");
-
-        for (final String node : nodes) {
-            // With 1 Zen1 node when you stop the Zen1 node the Zen2 nodes might auto-bootstrap.
-            // But there are only 2 Zen2 nodes so you must do the right things with voting config exclusions to keep the cluster
-            // alive through the other two restarts.
-            final boolean masterNodeIsZen2 = zen1NodeCount <= nodes.indexOf(internalCluster().getMasterName());
-            final boolean thisNodeIsZen2 = zen1NodeCount <= nodes.indexOf(node);
-            final boolean requiresVotingConfigExclusions = zen1NodeCount == 1 && zen2NodeCount == 2 && masterNodeIsZen2 && thisNodeIsZen2;
-
-            if (requiresVotingConfigExclusions) {
-                client().execute(AddVotingConfigExclusionsAction.INSTANCE,
-                    new AddVotingConfigExclusionsRequest(new String[]{node})).get();
-            }
-
-            internalCluster().restartNode(node, new RestartCallback() {
-                @Override
-                public Settings onNodeStopped(String restartingNode) {
-                    String viaNode = randomValueOtherThan(restartingNode, () -> randomFrom(nodes));
-                    final ClusterHealthRequestBuilder clusterHealthRequestBuilder = client(viaNode).admin().cluster().prepareHealth()
-                        .setWaitForEvents(Priority.LANGUID)
-                        .setWaitForNodes(Integer.toString(zen1NodeCount + zen2NodeCount - 1))
-                        .setTimeout(TimeValue.timeValueSeconds(30));
-                    ClusterHealthResponse clusterHealthResponse = clusterHealthRequestBuilder.get();
-                    assertFalse(restartingNode, clusterHealthResponse.isTimedOut());
-                    return Settings.EMPTY;
-                }
-            });
-            ensureStableCluster(zen1NodeCount + zen2NodeCount);
-            ensureGreen("test");
-
-            if (requiresVotingConfigExclusions) {
-                final ClearVotingConfigExclusionsRequest clearVotingTombstonesRequest = new ClearVotingConfigExclusionsRequest();
-                clearVotingTombstonesRequest.setWaitForRemoval(false);
-                client().execute(ClearVotingConfigExclusionsAction.INSTANCE, clearVotingTombstonesRequest).get();
-            }
-        }
-    }
-
-    public void testRollingMigrationFromZen1ToZen2() throws Exception {
-        final int nodeCount = randomIntBetween(2, 5);
-        final List<String> zen1Nodes = internalCluster().startNodes(nodeCount, ZEN1_SETTINGS);
-
-        createIndex("test",
-            Settings.builder()
-                .put(UnassignedInfo.INDEX_DELAYED_NODE_LEFT_TIMEOUT_SETTING.getKey(), TimeValue.ZERO) // assign shards
-                .put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, nodeCount) // causes rebalancing
-                .put(IndexMetaData.SETTING_NUMBER_OF_REPLICAS, 1)
-                .build());
-        ensureGreen("test");
-
-        for (final String zen1Node : zen1Nodes) {
-            logger.info("--> shutting down {}", zen1Node);
-            internalCluster().stopRandomNode(s -> NODE_NAME_SETTING.get(s).equals(zen1Node));
-
-            ensureStableCluster(nodeCount - 1);
-            if (nodeCount > 2) {
-                ensureGreen("test");
-            } else {
-                ensureYellow("test");
-            }
-
-            logger.info("--> starting replacement for {}", zen1Node);
-            final String newNode = internalCluster().startNode(ZEN2_SETTINGS);
-            ensureStableCluster(nodeCount);
-            ensureGreen("test");
-            logger.info("--> successfully replaced {} with {}", zen1Node, newNode);
-        }
-
-        assertThat(internalCluster().size(), equalTo(nodeCount));
-    }
-
-    public void testRollingUpgradeFromZen1ToZen2() throws Exception {
-        final int nodeCount = randomIntBetween(2, 5);
-        final List<String> nodes = internalCluster().startNodes(nodeCount, ZEN1_SETTINGS);
-
-        createIndex("test",
-            Settings.builder()
-                .put(UnassignedInfo.INDEX_DELAYED_NODE_LEFT_TIMEOUT_SETTING.getKey(), TimeValue.ZERO) // assign shards
-                .put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, nodeCount) // causes rebalancing
-                .put(IndexMetaData.SETTING_NUMBER_OF_REPLICAS, 1)
-                .build());
-        ensureGreen("test");
-
-        internalCluster().rollingRestart(new RestartCallback() {
-            @Override
-            public void doAfterNodes(int n, Client client) {
-                ensureGreen("test");
-            }
-
-            @Override
-            public Settings onNodeStopped(String nodeName) {
-                String viaNode = randomValueOtherThan(nodeName, () -> randomFrom(nodes));
-                final ClusterHealthRequestBuilder clusterHealthRequestBuilder = client(viaNode).admin().cluster().prepareHealth()
-                    .setWaitForEvents(Priority.LANGUID)
-                    .setWaitForNodes(Integer.toString(nodeCount - 1))
-                    .setTimeout(TimeValue.timeValueSeconds(30));
-                if (nodeCount == 2) {
-                    clusterHealthRequestBuilder.setWaitForYellowStatus();
-                } else {
-                    clusterHealthRequestBuilder.setWaitForGreenStatus();
-                }
-                ClusterHealthResponse clusterHealthResponse = clusterHealthRequestBuilder.get();
-                assertFalse(nodeName, clusterHealthResponse.isTimedOut());
-                return Coordinator.addZen1Attribute(false, Settings.builder().put(ZEN2_SETTINGS)
-                    .put(ElectMasterService.DISCOVERY_ZEN_MINIMUM_MASTER_NODES_SETTING.getKey(), REMOVED_MINIMUM_MASTER_NODES)).build();
-            }
-        });
-
-        ensureStableCluster(nodeCount);
-        ensureGreen("test");
-        assertThat(internalCluster().size(), equalTo(nodeCount));
-    }
-
-    private void testMultipleNodeMigrationFromZen1ToZen2(int nodeCount) throws Exception {
-        final List<String> oldNodes = internalCluster().startNodes(nodeCount, ZEN1_SETTINGS);
-        createIndex("test",
-            Settings.builder()
-                .put(UnassignedInfo.INDEX_DELAYED_NODE_LEFT_TIMEOUT_SETTING.getKey(), TimeValue.ZERO) // assign shards
-                .put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, nodeCount) // causes rebalancing
-                .put(IndexMetaData.SETTING_NUMBER_OF_REPLICAS, nodeCount > 1 ? 1 : 0)
-                .build());
-        ensureGreen("test");
-
-        internalCluster().startNodes(nodeCount, ZEN2_SETTINGS);
-
-        logger.info("--> updating settings to exclude old nodes");
-        client().admin().cluster().prepareUpdateSettings().setPersistentSettings(Settings.builder()
-            .put(CLUSTER_ROUTING_EXCLUDE_GROUP_SETTING.getConcreteSettingForNamespace("_name").getKey(), String.join(",", oldNodes))).get();
-
-        logger.info("--> waiting for old nodes to be vacated");
-        waitForRelocation();
-
-        while (internalCluster().size() > nodeCount) {
-            internalCluster().stopRandomNode(settings -> oldNodes.contains(NODE_NAME_SETTING.get(settings)));
-        }
-
-        ensureGreen("test");
-    }
-
-    public void testMultipleNodeMigrationFromZen1ToZen2WithOneNode() throws Exception {
-        testMultipleNodeMigrationFromZen1ToZen2(1);
-    }
-
-    public void testMultipleNodeMigrationFromZen1ToZen2WithTwoNodes() throws Exception {
-        testMultipleNodeMigrationFromZen1ToZen2(2);
-    }
-
-    public void testMultipleNodeMigrationFromZen1ToZen2WithThreeNodes() throws Exception {
-        testMultipleNodeMigrationFromZen1ToZen2(3);
-    }
-
-    public void testFreshestMasterElectedAfterFullClusterRestart() throws Exception {
-        final List<String> nodeNames = internalCluster().startNodes(3, ZEN1_SETTINGS);
-
-        assertTrue(client().admin().cluster().prepareUpdateSettings().setPersistentSettings(Settings.builder()
-            .put(CLUSTER_ROUTING_ALLOCATION_ENABLE_SETTING.getKey(), Allocation.ALL)).get().isAcknowledged());
-
-        final List<NodeEnvironment> nodeEnvironments
-            = StreamSupport.stream(internalCluster().getDataOrMasterNodeInstances(NodeEnvironment.class).spliterator(), false)
-            .collect(Collectors.toList());
-
-        final boolean randomiseVersions = rarely();
-
-        internalCluster().fullRestart(new RestartCallback() {
-            int nodesStopped;
-
-            @Override
-            public Settings onNodeStopped(String nodeName) throws Exception {
-                nodesStopped += 1;
-
-                if (nodesStopped == 1) {
-                    final Client client = internalCluster().client(randomValueOtherThan(nodeName, () -> randomFrom(nodeNames)));
-
-                    assertFalse(client.admin().cluster().health(Requests.clusterHealthRequest()
-                        .waitForEvents(Priority.LANGUID)
-                        .waitForNoRelocatingShards(true)
-                        .waitForNodes("2")).actionGet().isTimedOut());
-
-                    assertTrue(client.admin().cluster().prepareUpdateSettings().setPersistentSettings(Settings.builder()
-                        .put(CLUSTER_ROUTING_ALLOCATION_ENABLE_SETTING.getKey(), Allocation.NONE)).get().isAcknowledged());
-                }
-
-                if (nodesStopped == nodeNames.size()) {
-                    for (final NodeEnvironment nodeEnvironment : nodeEnvironments) {
-                        // The versions written by nodes following a Zen1 master cannot be trusted. Randomise them to demonstrate they are
-                        // not important.
-                        final MetaStateService metaStateService = new MetaStateService(nodeEnvironment, xContentRegistry());
-                        final Manifest manifest = metaStateService.loadManifestOrEmpty();
-                        assertThat(manifest.getCurrentTerm(), is(ZEN1_BWC_TERM));
-                        final long newVersion = randomiseVersions ? randomNonNegativeLong() : 0L;
-                        metaStateService.writeManifestAndCleanup("altering version to " + newVersion,
-                            new Manifest(manifest.getCurrentTerm(), newVersion, manifest.getGlobalGeneration(),
-                                manifest.getIndexGenerations()));
-                    }
-                }
-
-                return Coordinator.addZen1Attribute(false, Settings.builder())
-                    .put(ZEN2_SETTINGS)
-                    .putList(INITIAL_MASTER_NODES_SETTING.getKey(), nodeNames)
-                    .put(ElectMasterService.DISCOVERY_ZEN_MINIMUM_MASTER_NODES_SETTING.getKey(), REMOVED_MINIMUM_MASTER_NODES)
-                    .build();
-            }
-        });
-
-        assertFalse(client().admin().cluster().health(Requests.clusterHealthRequest()
-            .waitForEvents(Priority.LANGUID)
-            .waitForNoRelocatingShards(true)
-            .waitForNodes("3")).actionGet().isTimedOut());
-
-        assertThat(CLUSTER_ROUTING_ALLOCATION_ENABLE_SETTING.get(
-            client().admin().cluster().state(new ClusterStateRequest()).get().getState().metaData().settings()),
-            equalTo(Allocation.NONE));
-    }
-}
diff --git a/server/src/test/java/org/elasticsearch/cluster/metadata/MetaDataIndexUpgradeServiceTests.java b/server/src/test/java/org/elasticsearch/cluster/metadata/MetaDataIndexUpgradeServiceTests.java
index c1e341fd5bc2f..827680cca1b71 100644
--- a/server/src/test/java/org/elasticsearch/cluster/metadata/MetaDataIndexUpgradeServiceTests.java
+++ b/server/src/test/java/org/elasticsearch/cluster/metadata/MetaDataIndexUpgradeServiceTests.java
@@ -89,7 +89,10 @@ public void testFailUpgrade() {
             new MapperRegistry(Collections.emptyMap(), Collections.emptyMap(), MapperPlugin.NOOP_FIELD_FILTER),
                 IndexScopedSettings.DEFAULT_SCOPED_SETTINGS, Collections.emptyList());
         Version minCompat = Version.CURRENT.minimumIndexCompatibilityVersion();
-        Version indexUpgraded = VersionUtils.randomVersionBetween(random(), minCompat, VersionUtils.getPreviousVersion(Version.CURRENT));
+        Version indexUpgraded = VersionUtils.randomVersionBetween(random(),
+            minCompat,
+            Version.max(minCompat, VersionUtils.getPreviousVersion(Version.CURRENT))
+        );
         Version indexCreated = Version.fromString((minCompat.major - 1) + "." + randomInt(5) + "." + randomInt(5));
         final IndexMetaData metaData = newIndexMeta("foo", Settings.builder()
             .put(IndexMetaData.SETTING_VERSION_UPGRADED, indexUpgraded)
diff --git a/server/src/test/java/org/elasticsearch/index/seqno/RetentionLeaseIT.java b/server/src/test/java/org/elasticsearch/index/seqno/RetentionLeaseIT.java
index 13dadd051c273..a2880c0d330ad 100644
--- a/server/src/test/java/org/elasticsearch/index/seqno/RetentionLeaseIT.java
+++ b/server/src/test/java/org/elasticsearch/index/seqno/RetentionLeaseIT.java
@@ -260,6 +260,7 @@ public void testBackgroundRetentionLeaseSync() throws Exception {
         }
     }
 
+    @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/38588")
     public void testRetentionLeasesSyncOnRecovery() throws Exception {
         final int numberOfReplicas = 2 - scaledRandomIntBetween(0, 2);
         internalCluster().ensureAtLeastNumDataNodes(1 + numberOfReplicas);
diff --git a/server/src/test/java/org/elasticsearch/rest/action/admin/indices/RestResizeHandlerTests.java b/server/src/test/java/org/elasticsearch/rest/action/admin/indices/RestResizeHandlerTests.java
deleted file mode 100644
index b9da177b0b8fa..0000000000000
--- a/server/src/test/java/org/elasticsearch/rest/action/admin/indices/RestResizeHandlerTests.java
+++ /dev/null
@@ -1,77 +0,0 @@
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-
-package org.elasticsearch.rest.action.admin.indices;
-
-import org.elasticsearch.client.node.NodeClient;
-import org.elasticsearch.common.settings.Settings;
-import org.elasticsearch.common.xcontent.NamedXContentRegistry;
-import org.elasticsearch.rest.RestController;
-import org.elasticsearch.test.ESTestCase;
-import org.elasticsearch.test.rest.FakeRestRequest;
-
-import java.io.IOException;
-import java.util.Collections;
-import java.util.Locale;
-
-import static org.hamcrest.Matchers.containsString;
-import static org.hamcrest.Matchers.hasToString;
-import static org.mockito.Mockito.mock;
-
-public class RestResizeHandlerTests extends ESTestCase {
-
-    public void testShrinkCopySettingsDeprecated() throws IOException {
-        final RestResizeHandler.RestShrinkIndexAction handler =
-                new RestResizeHandler.RestShrinkIndexAction(Settings.EMPTY, mock(RestController.class));
-        for (final String copySettings : new String[]{null, "", "true", "false"}) {
-            runTestResizeCopySettingsDeprecated(handler, "shrink", copySettings);
-        }
-    }
-
-    public void testSplitCopySettingsDeprecated() throws IOException {
-        final RestResizeHandler.RestSplitIndexAction handler =
-                new RestResizeHandler.RestSplitIndexAction(Settings.EMPTY, mock(RestController.class));
-        for (final String copySettings : new String[]{null, "", "true", "false"}) {
-            runTestResizeCopySettingsDeprecated(handler, "split", copySettings);
-        }
-    }
-
-    private void runTestResizeCopySettingsDeprecated(
-            final RestResizeHandler handler, final String resizeOperation, final String copySettings) throws IOException {
-        final FakeRestRequest.Builder builder =
-                new FakeRestRequest.Builder(NamedXContentRegistry.EMPTY)
-                        .withParams(Collections.singletonMap("copy_settings", copySettings))
-                        .withPath(String.format(Locale.ROOT, "source/_%s/target", resizeOperation));
-        if (copySettings != null) {
-            builder.withParams(Collections.singletonMap("copy_settings", copySettings));
-        }
-        final FakeRestRequest request = builder.build();
-        if ("false".equals(copySettings)) {
-            final IllegalArgumentException e =
-                    expectThrows(IllegalArgumentException.class, () -> handler.prepareRequest(request, mock(NodeClient.class)));
-            assertThat(e, hasToString(containsString("parameter [copy_settings] can not be explicitly set to [false]")));
-        } else {
-            handler.prepareRequest(request, mock(NodeClient.class));
-            if ("".equals(copySettings) || "true".equals(copySettings)) {
-                assertWarnings("parameter [copy_settings] is deprecated and will be removed in 8.0.0");
-            }
-        }
-    }
-
-}
diff --git a/test/framework/src/main/java/org/elasticsearch/test/VersionUtils.java b/test/framework/src/main/java/org/elasticsearch/test/VersionUtils.java
index 84c480b8d510b..f775f9f5b0121 100644
--- a/test/framework/src/main/java/org/elasticsearch/test/VersionUtils.java
+++ b/test/framework/src/main/java/org/elasticsearch/test/VersionUtils.java
@@ -52,7 +52,7 @@ static Tuple<List<Version>, List<Version>> resolveReleasedVersions(Version curre
         // this breaks b/c 5.x is still in version list but master doesn't care about it!
         //assert majorVersions.size() == 2;
         // TODO: remove oldVersions, we should only ever have 2 majors in Version
-        List<Version> oldVersions = majorVersions.getOrDefault((int)current.major - 2, Collections.emptyList());
+        List<List<Version>> oldVersions = splitByMinor(majorVersions.getOrDefault((int)current.major - 2, Collections.emptyList()));
         List<List<Version>> previousMajor = splitByMinor(majorVersions.get((int)current.major - 1));
         List<List<Version>> currentMajor = splitByMinor(majorVersions.get((int)current.major));
 
@@ -78,12 +78,21 @@ static Tuple<List<Version>, List<Version>> resolveReleasedVersions(Version curre
                 moveLastToUnreleased(stableVersions, unreleasedVersions);
             }
             // remove the next bugfix
-            moveLastToUnreleased(stableVersions, unreleasedVersions);
+            if (stableVersions.isEmpty() == false) {
+                moveLastToUnreleased(stableVersions, unreleasedVersions);
+            }
         }
 
-        List<Version> releasedVersions = Stream.concat(oldVersions.stream(),
-            Stream.concat(previousMajor.stream(), currentMajor.stream()).flatMap(List::stream))
-            .collect(Collectors.toList());
+        // If none of the previous major was released, then the last minor and bugfix of the old version was not released either.
+        if (previousMajor.isEmpty()) {
+            assert currentMajor.isEmpty() : currentMajor;
+            // minor of the old version is being staged
+            moveLastToUnreleased(oldVersions, unreleasedVersions);
+            // bugix of the old version is also being staged
+            moveLastToUnreleased(oldVersions, unreleasedVersions);
+        }
+        List<Version> releasedVersions = Stream.of(oldVersions, previousMajor, currentMajor)
+            .flatMap(List::stream).flatMap(List::stream).collect(Collectors.toList());
         Collections.sort(unreleasedVersions); // we add unreleased out of order, so need to sort here
         return new Tuple<>(Collections.unmodifiableList(releasedVersions), Collections.unmodifiableList(unreleasedVersions));
     }
diff --git a/test/framework/src/main/java/org/elasticsearch/transport/AbstractSimpleTransportTestCase.java b/test/framework/src/main/java/org/elasticsearch/transport/AbstractSimpleTransportTestCase.java
index 87343d4c82087..db00ed028d4e2 100644
--- a/test/framework/src/main/java/org/elasticsearch/transport/AbstractSimpleTransportTestCase.java
+++ b/test/framework/src/main/java/org/elasticsearch/transport/AbstractSimpleTransportTestCase.java
@@ -2387,7 +2387,7 @@ public String executor() {
                 assertEquals(1, transportStats.getRxCount());
                 assertEquals(1, transportStats.getTxCount());
                 assertEquals(25, transportStats.getRxSize().getBytes());
-                assertEquals(50, transportStats.getTxSize().getBytes());
+                assertEquals(51, transportStats.getTxSize().getBytes());
             });
             serviceC.sendRequest(connection, "internal:action", new TestRequest("hello world"), TransportRequestOptions.EMPTY,
                 transportResponseHandler);
@@ -2397,7 +2397,7 @@ public String executor() {
                 assertEquals(1, transportStats.getRxCount());
                 assertEquals(2, transportStats.getTxCount());
                 assertEquals(25, transportStats.getRxSize().getBytes());
-                assertEquals(106, transportStats.getTxSize().getBytes());
+                assertEquals(107, transportStats.getTxSize().getBytes());
             });
             sendResponseLatch.countDown();
             responseLatch.await();
@@ -2405,7 +2405,7 @@ public String executor() {
             assertEquals(2, stats.getRxCount());
             assertEquals(2, stats.getTxCount());
             assertEquals(46, stats.getRxSize().getBytes());
-            assertEquals(106, stats.getTxSize().getBytes());
+            assertEquals(107, stats.getTxSize().getBytes());
         } finally {
             serviceC.close();
         }
@@ -2502,7 +2502,7 @@ public String executor() {
                 assertEquals(1, transportStats.getRxCount());
                 assertEquals(1, transportStats.getTxCount());
                 assertEquals(25, transportStats.getRxSize().getBytes());
-                assertEquals(50, transportStats.getTxSize().getBytes());
+                assertEquals(51, transportStats.getTxSize().getBytes());
             });
             serviceC.sendRequest(connection, "internal:action", new TestRequest("hello world"), TransportRequestOptions.EMPTY,
                 transportResponseHandler);
@@ -2512,7 +2512,7 @@ public String executor() {
                 assertEquals(1, transportStats.getRxCount());
                 assertEquals(2, transportStats.getTxCount());
                 assertEquals(25, transportStats.getRxSize().getBytes());
-                assertEquals(106, transportStats.getTxSize().getBytes());
+                assertEquals(107, transportStats.getTxSize().getBytes());
             });
             sendResponseLatch.countDown();
             responseLatch.await();
@@ -2527,7 +2527,7 @@ public String executor() {
             // 49 bytes are the non-exception message bytes that have been received. It should include the initial
             // handshake message and the header, version, etc bytes in the exception message.
             assertEquals(failedMessage, 49 + streamOutput.bytes().length(), stats.getRxSize().getBytes());
-            assertEquals(106, stats.getTxSize().getBytes());
+            assertEquals(107, stats.getTxSize().getBytes());
         } finally {
             serviceC.close();
         }
diff --git a/test/framework/src/main/java/org/elasticsearch/upgrades/AbstractFullClusterRestartTestCase.java b/test/framework/src/main/java/org/elasticsearch/upgrades/AbstractFullClusterRestartTestCase.java
index 508949b561fb4..18215b6797ec1 100644
--- a/test/framework/src/main/java/org/elasticsearch/upgrades/AbstractFullClusterRestartTestCase.java
+++ b/test/framework/src/main/java/org/elasticsearch/upgrades/AbstractFullClusterRestartTestCase.java
@@ -20,49 +20,23 @@
 package org.elasticsearch.upgrades;
 
 import org.elasticsearch.Version;
-import org.elasticsearch.client.Request;
 import org.elasticsearch.common.Booleans;
-import org.elasticsearch.common.Strings;
-import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.test.rest.ESRestTestCase;
-import org.junit.Before;
-
-import java.io.IOException;
-
-import static org.elasticsearch.common.xcontent.XContentFactory.jsonBuilder;
-import static org.hamcrest.Matchers.equalTo;
 
 public abstract class AbstractFullClusterRestartTestCase extends ESRestTestCase {
 
     private final boolean runningAgainstOldCluster = Booleans.parseBoolean(System.getProperty("tests.is_old_cluster"));
 
-    @Before
-    public void init() throws IOException {
-        assertThat("we don't need this branch if we aren't compatible with 6.0",
-                Version.CURRENT.minimumIndexCompatibilityVersion().onOrBefore(Version.V_6_0_0), equalTo(true));
-        if (isRunningAgainstOldCluster() && getOldClusterVersion().before(Version.V_7_0_0)) {
-            XContentBuilder template = jsonBuilder();
-            template.startObject();
-            {
-                template.field("index_patterns", "*");
-                template.field("order", "0");
-                template.startObject("settings");
-                template.field("number_of_shards", 5);
-                template.endObject();
-            }
-            template.endObject();
-            Request createTemplate = new Request("PUT", "/_template/template");
-            createTemplate.setJsonEntity(Strings.toString(template));
-            client().performRequest(createTemplate);
-        }
-    }
-
     public final boolean isRunningAgainstOldCluster() {
         return runningAgainstOldCluster;
     }
 
     private final Version oldClusterVersion = Version.fromString(System.getProperty("tests.old_cluster_version"));
 
+    public final boolean isRunningAgainstAncientCluster() {
+        return isRunningAgainstOldCluster() && oldClusterVersion.before(Version.V_7_0_0);
+    }
+
     public final Version getOldClusterVersion() {
         return oldClusterVersion;
     }
diff --git a/x-pack/plugin/core/src/test/java/org/elasticsearch/protocol/xpack/watcher/GetWatchResponseTests.java b/x-pack/plugin/core/src/test/java/org/elasticsearch/protocol/xpack/watcher/GetWatchResponseTests.java
index 9b71079a6e5e7..4cc566adf31bb 100644
--- a/x-pack/plugin/core/src/test/java/org/elasticsearch/protocol/xpack/watcher/GetWatchResponseTests.java
+++ b/x-pack/plugin/core/src/test/java/org/elasticsearch/protocol/xpack/watcher/GetWatchResponseTests.java
@@ -6,6 +6,7 @@
 package org.elasticsearch.protocol.xpack.watcher;
 
 import org.elasticsearch.common.bytes.BytesReference;
+import org.elasticsearch.common.time.DateUtils;
 import org.elasticsearch.common.xcontent.DeprecationHandler;
 import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.ToXContent;
@@ -23,9 +24,6 @@
 
 import java.io.IOException;
 import java.io.InputStream;
-import java.time.Clock;
-import java.time.Instant;
-import java.time.ZoneOffset;
 import java.time.ZonedDateTime;
 import java.util.Collections;
 import java.util.HashMap;
@@ -126,15 +124,15 @@ private static BytesReference simpleWatch() {
 
     private static WatchStatus randomWatchStatus() {
         long version = randomLongBetween(-1, Long.MAX_VALUE);
-        WatchStatus.State state = new WatchStatus.State(randomBoolean(), nowWithMillisResolution());
+        WatchStatus.State state = new WatchStatus.State(randomBoolean(), DateUtils.nowWithMillisResolution());
         ExecutionState executionState = randomFrom(ExecutionState.values());
-        ZonedDateTime lastChecked = rarely() ? null : nowWithMillisResolution();
-        ZonedDateTime lastMetCondition = rarely() ? null : nowWithMillisResolution();
+        ZonedDateTime lastChecked = rarely() ? null : DateUtils.nowWithMillisResolution();
+        ZonedDateTime lastMetCondition = rarely() ? null : DateUtils.nowWithMillisResolution();
         int size = randomIntBetween(0, 5);
         Map<String, ActionStatus> actionMap = new HashMap<>();
         for (int i = 0; i < size; i++) {
             ActionStatus.AckStatus ack = new ActionStatus.AckStatus(
-                nowWithMillisResolution(),
+                DateUtils.nowWithMillisResolution(),
                 randomFrom(ActionStatus.AckStatus.State.values())
             );
             ActionStatus actionStatus = new ActionStatus(
@@ -154,16 +152,16 @@ private static WatchStatus randomWatchStatus() {
     }
 
     private static ActionStatus.Throttle randomThrottle() {
-        return new ActionStatus.Throttle(nowWithMillisResolution(), randomAlphaOfLengthBetween(10, 20));
+        return new ActionStatus.Throttle(DateUtils.nowWithMillisResolution(), randomAlphaOfLengthBetween(10, 20));
     }
 
     private static ActionStatus.Execution randomExecution() {
         if (randomBoolean()) {
             return null;
         } else if (randomBoolean()) {
-            return ActionStatus.Execution.failure(nowWithMillisResolution(), randomAlphaOfLengthBetween(10, 20));
+            return ActionStatus.Execution.failure(DateUtils.nowWithMillisResolution(), randomAlphaOfLengthBetween(10, 20));
         } else {
-            return ActionStatus.Execution.successful(nowWithMillisResolution());
+            return ActionStatus.Execution.successful(DateUtils.nowWithMillisResolution());
         }
     }
 
@@ -229,8 +227,4 @@ private static ActionStatus.Execution convertHlrcToInternal(org.elasticsearch.cl
     private static ActionStatus.Throttle convertHlrcToInternal(org.elasticsearch.client.watcher.ActionStatus.Throttle throttle) {
         return new ActionStatus.Throttle(throttle.timestamp(), throttle.reason());
     }
-
-    private static ZonedDateTime nowWithMillisResolution() {
-        return Instant.ofEpochMilli(Clock.systemUTC().millis()).atZone(ZoneOffset.UTC);
-    }
 }
diff --git a/x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/ml/calendars/ScheduledEventTests.java b/x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/ml/calendars/ScheduledEventTests.java
index 6508ee5cb2054..9555d364a7bb1 100644
--- a/x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/ml/calendars/ScheduledEventTests.java
+++ b/x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/ml/calendars/ScheduledEventTests.java
@@ -7,6 +7,7 @@
 
 import org.elasticsearch.ElasticsearchStatusException;
 import org.elasticsearch.common.io.stream.Writeable;
+import org.elasticsearch.common.time.DateUtils;
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.common.xcontent.json.JsonXContent;
@@ -17,9 +18,6 @@
 import org.elasticsearch.xpack.core.ml.job.config.RuleCondition;
 
 import java.io.IOException;
-import java.time.Clock;
-import java.time.Instant;
-import java.time.ZoneOffset;
 import java.time.ZonedDateTime;
 import java.util.EnumSet;
 import java.util.List;
@@ -29,7 +27,7 @@
 public class ScheduledEventTests extends AbstractSerializingTestCase<ScheduledEvent> {
 
     public static ScheduledEvent createScheduledEvent(String calendarId) {
-        ZonedDateTime start = nowWithMillisResolution();
+        ZonedDateTime start = DateUtils.nowWithMillisResolution();
         return new ScheduledEvent(randomAlphaOfLength(10), start, start.plusSeconds(randomIntBetween(1, 10000)),
                 calendarId, null);
     }
@@ -120,8 +118,4 @@ public void testLenientParser() throws IOException {
             ScheduledEvent.LENIENT_PARSER.apply(parser, null);
         }
     }
-
-    private static ZonedDateTime nowWithMillisResolution() {
-        return Instant.ofEpochMilli(Clock.systemUTC().millis()).atZone(ZoneOffset.UTC);
-    }
 }
diff --git a/x-pack/plugin/security/src/test/java/org/elasticsearch/xpack/security/authc/ApiKeyIntegTests.java b/x-pack/plugin/security/src/test/java/org/elasticsearch/xpack/security/authc/ApiKeyIntegTests.java
index 69e008f60c696..62cb04f035318 100644
--- a/x-pack/plugin/security/src/test/java/org/elasticsearch/xpack/security/authc/ApiKeyIntegTests.java
+++ b/x-pack/plugin/security/src/test/java/org/elasticsearch/xpack/security/authc/ApiKeyIntegTests.java
@@ -237,6 +237,7 @@ public void testInvalidateApiKeysForApiKeyName() throws InterruptedException, Ex
         verifyInvalidateResponse(1, responses, invalidateResponse);
     }
 
+    @AwaitsFix(bugUrl="https://github.com/elastic/elasticsearch/issues/38408")
     public void testGetAndInvalidateApiKeysWithExpiredAndInvalidatedApiKey() throws Exception {
         List<CreateApiKeyResponse> responses = createApiKeys(1, null);
         Instant created = Instant.now();
diff --git a/x-pack/plugin/sql/src/test/java/org/elasticsearch/xpack/sql/TestUtils.java b/x-pack/plugin/sql/src/test/java/org/elasticsearch/xpack/sql/TestUtils.java
index be7f42d3f0c78..9b8fbdef43a77 100644
--- a/x-pack/plugin/sql/src/test/java/org/elasticsearch/xpack/sql/TestUtils.java
+++ b/x-pack/plugin/sql/src/test/java/org/elasticsearch/xpack/sql/TestUtils.java
@@ -11,10 +11,6 @@
 import org.elasticsearch.xpack.sql.session.Configuration;
 import org.elasticsearch.xpack.sql.util.DateUtils;
 
-import java.time.Clock;
-import java.time.Duration;
-import java.time.ZonedDateTime;
-
 public class TestUtils {
 
     private TestUtils() {}
@@ -23,16 +19,4 @@ private TestUtils() {}
             Protocol.REQUEST_TIMEOUT, Protocol.PAGE_TIMEOUT, null, Mode.PLAIN,
             null, null, null);
 
-    /**
-     * Returns the current UTC date-time with milliseconds precision.
-     * In Java 9+ (as opposed to Java 8) the {@code Clock} implementation uses system's best clock implementation (which could mean
-     * that the precision of the clock can be milliseconds, microseconds or nanoseconds), whereas in Java 8
-     * {@code System.currentTimeMillis()} is always used. To account for these differences, this method defines a new {@code Clock}
-     * which will offer a value for {@code ZonedDateTime.now()} set to always have milliseconds precision.
-     * 
-     * @return {@link ZonedDateTime} instance for the current date-time with milliseconds precision in UTC
-     */
-    public static final ZonedDateTime now() {
-        return ZonedDateTime.now(Clock.tick(Clock.system(DateUtils.UTC), Duration.ofMillis(1)));
-    }
 }
diff --git a/x-pack/plugin/sql/src/test/java/org/elasticsearch/xpack/sql/type/DataTypeConversionTests.java b/x-pack/plugin/sql/src/test/java/org/elasticsearch/xpack/sql/type/DataTypeConversionTests.java
index 73b4ea8fa8daa..686c97b91a06b 100644
--- a/x-pack/plugin/sql/src/test/java/org/elasticsearch/xpack/sql/type/DataTypeConversionTests.java
+++ b/x-pack/plugin/sql/src/test/java/org/elasticsearch/xpack/sql/type/DataTypeConversionTests.java
@@ -7,7 +7,6 @@
 
 import org.elasticsearch.test.ESTestCase;
 import org.elasticsearch.xpack.sql.SqlIllegalArgumentException;
-import org.elasticsearch.xpack.sql.TestUtils;
 import org.elasticsearch.xpack.sql.expression.Literal;
 import org.elasticsearch.xpack.sql.tree.Location;
 import org.elasticsearch.xpack.sql.tree.Source;
@@ -157,7 +156,8 @@ public void testConversionToDate() {
             assertEquals(date(18000000L), conversion.convert("1970-01-01T03:10:20-05:00"));
 
             // double check back and forth conversion
-            ZonedDateTime zdt = TestUtils.now();
+
+            ZonedDateTime zdt = org.elasticsearch.common.time.DateUtils.nowWithMillisResolution();
             Conversion forward = conversionFor(DATE, KEYWORD);
             Conversion back = conversionFor(KEYWORD, DATE);
             assertEquals(DateUtils.asDateOnly(zdt), back.convert(forward.convert(zdt)));
@@ -205,7 +205,8 @@ public void testConversionToDateTime() {
             assertEquals(dateTime(18000000L), conversion.convert("1970-01-01T00:00:00-05:00"));
 
             // double check back and forth conversion
-            ZonedDateTime dt = TestUtils.now();
+
+            ZonedDateTime dt = org.elasticsearch.common.time.DateUtils.nowWithMillisResolution();
             Conversion forward = conversionFor(DATETIME, KEYWORD);
             Conversion back = conversionFor(KEYWORD, DATETIME);
             assertEquals(dt, back.convert(forward.convert(dt)));
diff --git a/x-pack/plugin/watcher/src/main/java/org/elasticsearch/xpack/watcher/WatcherIndexingListener.java b/x-pack/plugin/watcher/src/main/java/org/elasticsearch/xpack/watcher/WatcherIndexingListener.java
index 48e8dd7813e19..81fda0c0bd47c 100644
--- a/x-pack/plugin/watcher/src/main/java/org/elasticsearch/xpack/watcher/WatcherIndexingListener.java
+++ b/x-pack/plugin/watcher/src/main/java/org/elasticsearch/xpack/watcher/WatcherIndexingListener.java
@@ -32,7 +32,6 @@
 
 import java.io.IOException;
 import java.time.Clock;
-import java.time.Instant;
 import java.time.ZoneOffset;
 import java.time.ZonedDateTime;
 import java.util.ArrayList;
@@ -102,7 +101,7 @@ void setConfiguration(Configuration configuration) {
     @Override
     public Engine.Index preIndex(ShardId shardId, Engine.Index operation) {
         if (isWatchDocument(shardId.getIndexName(), operation.type())) {
-            ZonedDateTime now = Instant.ofEpochMilli(clock.millis()).atZone(ZoneOffset.UTC);
+            ZonedDateTime now = clock.instant().atZone(ZoneOffset.UTC);
             try {
                 Watch watch = parser.parseWithSecrets(operation.id(), true, operation.source(), now, XContentType.JSON,
                     operation.getIfSeqNo(), operation.getIfPrimaryTerm());
diff --git a/x-pack/plugin/watcher/src/test/java/org/elasticsearch/xpack/watcher/actions/index/IndexActionTests.java b/x-pack/plugin/watcher/src/test/java/org/elasticsearch/xpack/watcher/actions/index/IndexActionTests.java
index da702e01047bd..1864bd3bd5cce 100644
--- a/x-pack/plugin/watcher/src/test/java/org/elasticsearch/xpack/watcher/actions/index/IndexActionTests.java
+++ b/x-pack/plugin/watcher/src/test/java/org/elasticsearch/xpack/watcher/actions/index/IndexActionTests.java
@@ -17,6 +17,7 @@
 import org.elasticsearch.client.Client;
 import org.elasticsearch.common.collect.MapBuilder;
 import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.time.DateUtils;
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.common.util.concurrent.ThreadContext;
 import org.elasticsearch.common.xcontent.XContentBuilder;
@@ -36,6 +37,7 @@
 
 import java.time.ZoneOffset;
 import java.time.ZonedDateTime;
+import java.time.format.DateTimeFormatter;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -285,7 +287,7 @@ public void testIndexActionExecuteSingleDoc() throws Exception {
                 refreshPolicy);
         ExecutableIndexAction executable = new ExecutableIndexAction(action, logger, client, TimeValue.timeValueSeconds(30),
                 TimeValue.timeValueSeconds(30));
-        ZonedDateTime executionTime = ZonedDateTime.now(ZoneOffset.UTC);
+        ZonedDateTime executionTime = DateUtils.nowWithMillisResolution();
         Payload payload;
 
         if (customId && docIdAsParam == false) {
@@ -324,8 +326,9 @@ public void testIndexActionExecuteSingleDoc() throws Exception {
         assertThat(indexRequest.getRefreshPolicy(), is(expectedRefreshPolicy));
 
         if (timestampField != null) {
+            final DateTimeFormatter formatter = DateTimeFormatter.ISO_DATE_TIME;
             assertThat(indexRequest.sourceAsMap().keySet(), is(hasSize(2)));
-            assertThat(indexRequest.sourceAsMap(), hasEntry(timestampField, executionTime.toString()));
+            assertThat(indexRequest.sourceAsMap(), hasEntry(timestampField, formatter.format(executionTime)));
         } else {
             assertThat(indexRequest.sourceAsMap().keySet(), is(hasSize(1)));
         }
diff --git a/x-pack/plugin/watcher/src/test/java/org/elasticsearch/xpack/watcher/watch/WatchStatusIntegrationTests.java b/x-pack/plugin/watcher/src/test/java/org/elasticsearch/xpack/watcher/watch/WatchStatusIntegrationTests.java
index 9f738d8daa6b2..20e27bd8b8d15 100644
--- a/x-pack/plugin/watcher/src/test/java/org/elasticsearch/xpack/watcher/watch/WatchStatusIntegrationTests.java
+++ b/x-pack/plugin/watcher/src/test/java/org/elasticsearch/xpack/watcher/watch/WatchStatusIntegrationTests.java
@@ -24,6 +24,7 @@
 
 public class WatchStatusIntegrationTests extends AbstractWatcherIntegrationTestCase {
 
+    @AwaitsFix(bugUrl="https://github.com/elastic/elasticsearch/issues/38619")
     public void testThatStatusGetsUpdated() {
         WatcherClient watcherClient = watcherClient();
         watcherClient.preparePutWatch("_name")
diff --git a/x-pack/qa/full-cluster-restart/src/test/java/org/elasticsearch/xpack/restart/FullClusterRestartIT.java b/x-pack/qa/full-cluster-restart/src/test/java/org/elasticsearch/xpack/restart/FullClusterRestartIT.java
index e4d96645b87b7..c7bea7b108804 100644
--- a/x-pack/qa/full-cluster-restart/src/test/java/org/elasticsearch/xpack/restart/FullClusterRestartIT.java
+++ b/x-pack/qa/full-cluster-restart/src/test/java/org/elasticsearch/xpack/restart/FullClusterRestartIT.java
@@ -32,6 +32,7 @@
 import org.elasticsearch.xpack.watcher.trigger.schedule.IntervalSchedule;
 import org.elasticsearch.xpack.watcher.trigger.schedule.ScheduleTrigger;
 import org.hamcrest.Matcher;
+import org.junit.Before;
 
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
@@ -60,6 +61,13 @@
 
 public class FullClusterRestartIT extends AbstractFullClusterRestartTestCase {
 
+    private String type;
+
+    @Before
+    public void setType() {
+        type = getOldClusterVersion().before(Version.V_6_7_0) ? "doc" : "_doc";
+    }
+
     @Override
     protected Settings restClientSettings() {
         String token = "Basic " + Base64.getEncoder().encodeToString("test_user:x-pack-test-password".getBytes(StandardCharsets.UTF_8));
@@ -76,7 +84,7 @@ protected Settings restClientSettings() {
      * Tests that a single document survives. Super basic smoke test.
      */
     public void testSingleDoc() throws IOException {
-        String docLocation = "/testsingledoc/doc/1";
+        String docLocation = "/testsingledoc/" + type + "/1";
         String doc = "{\"test\": \"test\"}";
 
         if (isRunningAgainstOldCluster()) {
@@ -87,7 +95,9 @@ public void testSingleDoc() throws IOException {
         }
 
         Request getRequest = new Request("GET", docLocation);
-        getRequest.setOptions(expectWarnings(RestGetAction.TYPES_DEPRECATION_MESSAGE));
+        if (getOldClusterVersion().before(Version.V_6_7_0)) {
+            getRequest.setOptions(expectWarnings(RestGetAction.TYPES_DEPRECATION_MESSAGE));
+        }
         assertThat(toStr(client().performRequest(getRequest)), containsString(doc));
     }
 
@@ -148,17 +158,21 @@ public void testSecurityNativeRealm() throws Exception {
     public void testWatcher() throws Exception {
         if (isRunningAgainstOldCluster()) {
             logger.info("Adding a watch on old cluster {}", getOldClusterVersion());
-            Request createBwcWatch = new Request("PUT", "/_xpack/watcher/watch/bwc_watch");
+            Request createBwcWatch = new Request("PUT", getWatcherEndpoint() + "/watch/bwc_watch");
+            Request createBwcThrottlePeriod = new Request("PUT", getWatcherEndpoint() + "/watch/bwc_throttle_period");
+            if (getOldClusterVersion().onOrAfter(Version.V_7_0_0)) {
+                createBwcWatch.setOptions(expectWarnings(IndexAction.TYPES_DEPRECATION_MESSAGE));
+                createBwcThrottlePeriod.setOptions(expectWarnings(IndexAction.TYPES_DEPRECATION_MESSAGE));
+            }
             createBwcWatch.setJsonEntity(loadWatch("simple-watch.json"));
             client().performRequest(createBwcWatch);
 
             logger.info("Adding a watch with \"fun\" throttle periods on old cluster");
-            Request createBwcThrottlePeriod = new Request("PUT", "_xpack/watcher/watch/bwc_throttle_period");
             createBwcThrottlePeriod.setJsonEntity(loadWatch("throttle-period-watch.json"));
             client().performRequest(createBwcThrottlePeriod);
 
             logger.info("Adding a watch with \"fun\" read timeout on old cluster");
-            Request createFunnyTimeout = new Request("PUT", "_xpack/watcher/watch/bwc_funny_timeout");
+            Request createFunnyTimeout = new Request("PUT", getWatcherEndpoint() + "/watch/bwc_funny_timeout");
             createFunnyTimeout.setJsonEntity(loadWatch("funny-timeout-watch.json"));
             client().performRequest(createFunnyTimeout);
 
@@ -246,7 +260,11 @@ public void testRollupAfterRestart() throws Exception {
             // index documents for the rollup job
             final StringBuilder bulk = new StringBuilder();
             for (int i = 0; i < numDocs; i++) {
-                bulk.append("{\"index\":{\"_index\":\"rollup-docs\",\"_type\":\"doc\"}}\n");
+                if (getOldClusterVersion().onOrAfter(Version.V_7_0_0)) {
+                    bulk.append("{\"index\":{\"_index\":\"rollup-docs\"}}\n");
+                } else {
+                    bulk.append("{\"index\":{\"_index\":\"rollup-docs\",\"_type\":\"doc\"}}\n");
+                }
                 String date = String.format(Locale.ROOT, "%04d-01-01T00:%02d:00Z", year, i);
                 bulk.append("{\"timestamp\":\"").append(date).append("\",\"value\":").append(i).append("}\n");
             }
@@ -257,7 +275,8 @@ public void testRollupAfterRestart() throws Exception {
             client().performRequest(bulkRequest);
 
             // create the rollup job
-            final Request createRollupJobRequest = new Request("PUT", "/_xpack/rollup/job/rollup-job-test");
+            final Request createRollupJobRequest = new Request("PUT", getRollupEndpoint() + "/job/rollup-job-test");
+
             createRollupJobRequest.setJsonEntity("{"
                     + "\"index_pattern\":\"rollup-*\","
                     + "\"rollup_index\":\"results-rollup\","
@@ -278,7 +297,7 @@ public void testRollupAfterRestart() throws Exception {
             assertThat(createRollupJobResponse.get("acknowledged"), equalTo(Boolean.TRUE));
 
             // start the rollup job
-            final Request startRollupJobRequest = new Request("POST", "/_xpack/rollup/job/rollup-job-test/_start");
+            final Request startRollupJobRequest = new Request("POST", getRollupEndpoint() + "/job/rollup-job-test/_start");
             Map<String, Object> startRollupJobResponse = entityAsMap(client().performRequest(startRollupJobRequest));
             assertThat(startRollupJobResponse.get("started"), equalTo(Boolean.TRUE));
 
@@ -304,12 +323,12 @@ public void testRollupIDSchemeAfterRestart() throws Exception {
         assumeTrue("Rollup ID scheme changed in 6.4", getOldClusterVersion().before(Version.V_6_4_0));
         if (isRunningAgainstOldCluster()) {
 
-            final Request indexRequest = new Request("POST", "/id-test-rollup/doc/1");
+            final Request indexRequest = new Request("POST", "/id-test-rollup" + type + "/1");
             indexRequest.setJsonEntity("{\"timestamp\":\"2018-01-01T00:00:01\",\"value\":123}");
             client().performRequest(indexRequest);
 
             // create the rollup job
-            final Request createRollupJobRequest = new Request("PUT", "/_xpack/rollup/job/rollup-id-test");
+            final Request createRollupJobRequest = new Request("PUT", getRollupEndpoint() + "/job/rollup-id-test");
             createRollupJobRequest.setJsonEntity("{"
                 + "\"index_pattern\":\"id-test-rollup\","
                 + "\"rollup_index\":\"id-test-results-rollup\","
@@ -337,7 +356,7 @@ public void testRollupIDSchemeAfterRestart() throws Exception {
             assertThat(createRollupJobResponse.get("acknowledged"), equalTo(Boolean.TRUE));
 
             // start the rollup job
-            final Request startRollupJobRequest = new Request("POST", "/_xpack/rollup/job/rollup-id-test/_start");
+            final Request startRollupJobRequest = new Request("POST", getRollupEndpoint() + "/job/rollup-id-test/_start");
             Map<String, Object> startRollupJobResponse = entityAsMap(client().performRequest(startRollupJobRequest));
             assertThat(startRollupJobResponse.get("started"), equalTo(Boolean.TRUE));
 
@@ -365,9 +384,11 @@ public void testRollupIDSchemeAfterRestart() throws Exception {
 
         } else {
 
-            final Request indexRequest = new Request("POST", "/id-test-rollup/doc/2");
+            final Request indexRequest = new Request("POST", "/id-test-rollup/" + type + "/2");
             indexRequest.setJsonEntity("{\"timestamp\":\"2018-01-02T00:00:01\",\"value\":345}");
-            indexRequest.setOptions(expectWarnings(RestIndexAction.TYPES_DEPRECATION_MESSAGE));
+            if (getOldClusterVersion().before(Version.V_6_7_0)) {
+                indexRequest.setOptions(expectWarnings(RestIndexAction.TYPES_DEPRECATION_MESSAGE));
+            }
             client().performRequest(indexRequest);
 
             assertRollUpJob("rollup-id-test");
@@ -431,12 +452,8 @@ public void testSqlFailsOnIndexWithTwoTypes() throws IOException {
             client().performRequest(doc2);
             return;
         }
-        final Request sqlRequest;
-        if (isRunningAgainstOldCluster()) {
-            sqlRequest = new Request("POST", "/_xpack/sql");
-        } else {
-            sqlRequest = new Request("POST", "/_sql");
-        }
+        final Request sqlRequest = new Request("POST", getSQLEndpoint());
+
         sqlRequest.setJsonEntity("{\"query\":\"SELECT * FROM testsqlfailsonindexwithtwotypes\"}");
         ResponseException e = expectThrows(ResponseException.class, () -> client().performRequest(sqlRequest));
         assertEquals(400, e.getResponse().getStatusLine().getStatusCode());
@@ -458,8 +475,21 @@ private void assertOldTemplatesAreDeleted() throws IOException {
     private void assertWatchIndexContentsWork() throws Exception {
         // Fetch a basic watch
         Request getRequest = new Request("GET", "_watcher/watch/bwc_watch");
-        getRequest.setOptions(expectWarnings(IndexAction.TYPES_DEPRECATION_MESSAGE,
-            WatcherSearchTemplateRequest.TYPES_DEPRECATION_MESSAGE));
+        if (getOldClusterVersion().before(Version.V_7_0_0)) {
+            getRequest.setOptions(
+                expectWarnings(
+                    IndexAction.TYPES_DEPRECATION_MESSAGE,
+                    WatcherSearchTemplateRequest.TYPES_DEPRECATION_MESSAGE
+                )
+            );
+        } else {
+            getRequest.setOptions(
+                expectWarnings(
+                    IndexAction.TYPES_DEPRECATION_MESSAGE
+                )
+            );
+        }
+
         Map<String, Object> bwcWatch = entityAsMap(client().performRequest(getRequest));
 
         logger.error("-----> {}", bwcWatch);
@@ -475,8 +505,20 @@ private void assertWatchIndexContentsWork() throws Exception {
 
         // Fetch a watch with "fun" throttle periods
         getRequest = new Request("GET", "_watcher/watch/bwc_throttle_period");
-        getRequest.setOptions(expectWarnings(IndexAction.TYPES_DEPRECATION_MESSAGE,
-            WatcherSearchTemplateRequest.TYPES_DEPRECATION_MESSAGE));
+        if (getOldClusterVersion().before(Version.V_7_0_0)) {
+            getRequest.setOptions(
+                expectWarnings(
+                    IndexAction.TYPES_DEPRECATION_MESSAGE,
+                    WatcherSearchTemplateRequest.TYPES_DEPRECATION_MESSAGE
+                )
+            );
+        } else {
+            getRequest.setOptions(
+                expectWarnings(
+                    IndexAction.TYPES_DEPRECATION_MESSAGE
+                )
+            );
+        }
         bwcWatch = entityAsMap(client().performRequest(getRequest));
         assertThat(bwcWatch.get("found"), equalTo(true));
         source = (Map<String, Object>) bwcWatch.get("watch");
@@ -560,7 +602,13 @@ private void waitForHits(String indexName, int expectedHits) throws Exception {
             try {
                 Map<String, Object> response = entityAsMap(client().performRequest(request));
                 Map<String, Object> hits = (Map<String, Object>) response.get("hits");
-                int total = (int) hits.get("total");
+                logger.info("Hits are: {}", hits);
+                int total;
+                if (getOldClusterVersion().onOrAfter(Version.V_7_0_0) || isRunningAgainstOldCluster() == false) {
+                    total = (int) ((Map<String, Object>) hits.get("total")).get("value");
+                } else {
+                    total = (int) hits.get("total");
+                }
                 assertThat(total, greaterThanOrEqualTo(expectedHits));
             } catch (IOException ioe) {
                 if (ioe instanceof ResponseException) {
@@ -580,12 +628,7 @@ static String toStr(Response response) throws IOException {
 
     private void createUser(final boolean oldCluster) throws Exception {
         final String id = oldCluster ? "preupgrade_user" : "postupgrade_user";
-        Request request;
-        if (oldCluster) {
-            request = new Request("PUT", "/_xpack/security/user/" + id);
-        } else {
-            request = new Request("PUT", "/_security/user/" + id);
-        }
+        Request request = new Request("PUT", getSecurityEndpoint() + "/user/" + id);
         request.setJsonEntity(
             "{\n" +
             "   \"password\" : \"j@rV1s\",\n" +
@@ -599,12 +642,7 @@ private void createUser(final boolean oldCluster) throws Exception {
 
     private void createRole(final boolean oldCluster) throws Exception {
         final String id = oldCluster ? "preupgrade_role" : "postupgrade_role";
-        Request request;
-        if (oldCluster) {
-            request = new Request("PUT", "/_xpack/security/role/" + id);
-        } else {
-            request = new Request("PUT", "/_security/role/" + id);
-        }
+        Request request = new Request("PUT", getSecurityEndpoint() + "/role/" + id);
         request.setJsonEntity(
             "{\n" +
             "  \"run_as\": [ \"abc\" ],\n" +
@@ -625,20 +663,59 @@ private void createRole(final boolean oldCluster) throws Exception {
 
     private void assertUserInfo(final boolean oldCluster) throws Exception {
         final String user = oldCluster ? "preupgrade_user" : "postupgrade_user";
-        Map<String, Object> response = oldCluster ?
-            entityAsMap(client().performRequest(new Request("GET", "/_xpack/security/user/" + user))) :
-            entityAsMap(client().performRequest(new Request("GET", "/_security/user/" + user)));
+        Request request = new Request("GET", getSecurityEndpoint() + "/user/" + user);;
+        Map<String, Object> response = entityAsMap(client().performRequest(request));
         @SuppressWarnings("unchecked") Map<String, Object> userInfo = (Map<String, Object>) response.get(user);
         assertEquals(user + "@example.com", userInfo.get("email"));
         assertNotNull(userInfo.get("full_name"));
         assertNotNull(userInfo.get("roles"));
     }
 
+    private String getSecurityEndpoint() {
+        String securityEndpoint;
+        if (getOldClusterVersion().onOrAfter(Version.V_7_0_0) || isRunningAgainstOldCluster() == false) {
+            securityEndpoint = "/_security";
+        } else {
+            securityEndpoint = "/_xpack/security";
+        }
+        return securityEndpoint;
+    }
+
+    private String getSQLEndpoint() {
+        String securityEndpoint;
+        if (getOldClusterVersion().onOrAfter(Version.V_7_0_0) || isRunningAgainstOldCluster() == false) {
+            securityEndpoint = "/_sql";
+        } else {
+            securityEndpoint = "/_xpack/sql";
+        }
+        return securityEndpoint;
+    }
+
+    private String getRollupEndpoint() {
+        String securityEndpoint;
+        if (getOldClusterVersion().onOrAfter(Version.V_7_0_0) || isRunningAgainstOldCluster() == false) {
+            securityEndpoint = "/_rollup";
+        } else {
+            securityEndpoint = "/_xpack/rollup";
+        }
+        return securityEndpoint;
+    }
+
+    private String getWatcherEndpoint() {
+        String securityEndpoint;
+        if (getOldClusterVersion().onOrAfter(Version.V_7_0_0) || isRunningAgainstOldCluster() == false) {
+            securityEndpoint = "/_watcher";
+        } else {
+            securityEndpoint = "/_xpack/watcher";
+        }
+        return securityEndpoint;
+    }
+
     private void assertRoleInfo(final boolean oldCluster) throws Exception {
         final String role = oldCluster ? "preupgrade_role" : "postupgrade_role";
-        @SuppressWarnings("unchecked") Map<String, Object> response = oldCluster ?
-            (Map<String, Object>) entityAsMap(client().performRequest(new Request("GET", "/_xpack/security/role/" + role))).get(role) :
-            (Map<String, Object>) entityAsMap(client().performRequest(new Request("GET", "/_security/role/" + role))).get(role);
+        @SuppressWarnings("unchecked") Map<String, Object> response = (Map<String, Object>) entityAsMap(
+            client().performRequest(new Request("GET", getSecurityEndpoint() + "/role/" + role))
+        ).get(role);
         assertNotNull(response.get("run_as"));
         assertNotNull(response.get("cluster"));
         assertNotNull(response.get("indices"));
@@ -650,12 +727,7 @@ private void assertRollUpJob(final String rollupJob) throws Exception {
         waitForRollUpJob(rollupJob, expectedStates);
 
         // check that the rollup job is started using the RollUp API
-        final Request getRollupJobRequest;
-        if (isRunningAgainstOldCluster()) {
-            getRollupJobRequest = new Request("GET", "/_xpack/rollup/job/" + rollupJob);
-        } else {
-            getRollupJobRequest = new Request("GET", "/_rollup/job/" + rollupJob);
-        }
+        final Request getRollupJobRequest = new Request("GET", getRollupEndpoint() + "/job/" + rollupJob);
         Map<String, Object> getRollupJobResponse = entityAsMap(client().performRequest(getRollupJobRequest));
         Map<String, Object> job = getJob(getRollupJobResponse, rollupJob);
         assertNotNull(job);
@@ -700,12 +772,8 @@ private void assertRollUpJob(final String rollupJob) throws Exception {
 
     private void waitForRollUpJob(final String rollupJob, final Matcher<?> expectedStates) throws Exception {
         assertBusy(() -> {
-            final Request getRollupJobRequest;
-            if (isRunningAgainstOldCluster()) {
-                getRollupJobRequest = new Request("GET", "/_xpack/rollup/job/" + rollupJob);
-            } else {
-                getRollupJobRequest = new Request("GET", "/_rollup/job/" + rollupJob);
-            }
+            final Request getRollupJobRequest = new Request("GET", getRollupEndpoint() + "/job/" + rollupJob);
+
             Response getRollupJobResponse = client().performRequest(getRollupJobRequest);
             assertThat(getRollupJobResponse.getStatusLine().getStatusCode(), equalTo(RestStatus.OK.getStatus()));
 
diff --git a/x-pack/qa/rolling-upgrade/src/test/java/org/elasticsearch/upgrades/IndexingIT.java b/x-pack/qa/rolling-upgrade/src/test/java/org/elasticsearch/upgrades/IndexingIT.java
index 8d8d999a55b8d..b44ae0360d884 100644
--- a/x-pack/qa/rolling-upgrade/src/test/java/org/elasticsearch/upgrades/IndexingIT.java
+++ b/x-pack/qa/rolling-upgrade/src/test/java/org/elasticsearch/upgrades/IndexingIT.java
@@ -6,20 +6,15 @@
 package org.elasticsearch.upgrades;
 
 import org.apache.http.util.EntityUtils;
-import org.elasticsearch.common.Booleans;
-import org.elasticsearch.common.Strings;
-import org.elasticsearch.common.xcontent.XContentBuilder;
-import org.elasticsearch.rest.action.document.RestBulkAction;
-import org.elasticsearch.Version;
 import org.elasticsearch.client.Request;
 import org.elasticsearch.client.Response;
+import org.elasticsearch.common.Booleans;
+import org.elasticsearch.rest.action.document.RestBulkAction;
 
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 
-import static org.elasticsearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.elasticsearch.rest.action.search.RestSearchAction.TOTAL_HITS_AS_INT_PARAM;
-import static org.hamcrest.Matchers.equalTo;
 
 /**
  * Basic test that indexed documents survive the rolling restart.
@@ -53,25 +48,6 @@ public void testIndexing() throws IOException {
         }
 
         if (CLUSTER_TYPE == ClusterType.OLD) {
-            {
-                Version minimumIndexCompatibilityVersion = Version.CURRENT.minimumIndexCompatibilityVersion();
-                assertThat("this branch is not needed if we aren't compatible with 6.0",
-                        minimumIndexCompatibilityVersion.onOrBefore(Version.V_6_0_0), equalTo(true));
-                if (minimumIndexCompatibilityVersion.before(Version.V_7_0_0)) {
-                    XContentBuilder template = jsonBuilder();
-                    template.startObject();
-                    {
-                        template.field("index_patterns", "*");
-                        template.startObject("settings");
-                        template.field("number_of_shards", 5);
-                        template.endObject();
-                    }
-                    template.endObject();
-                    Request createTemplate = new Request("PUT", "/_template/template");
-                    createTemplate.setJsonEntity(Strings.toString(template));
-                    client().performRequest(createTemplate);
-                }
-            }
 
             Request createTestIndex = new Request("PUT", "/test_index");
             createTestIndex.setJsonEntity("{\"settings\": {\"index.number_of_replicas\": 0}}");
diff --git a/x-pack/qa/rolling-upgrade/src/test/java/org/elasticsearch/upgrades/TokenBackwardsCompatibilityIT.java b/x-pack/qa/rolling-upgrade/src/test/java/org/elasticsearch/upgrades/TokenBackwardsCompatibilityIT.java
index 1f0b8cffe20b0..6c5fa0c1a9704 100644
--- a/x-pack/qa/rolling-upgrade/src/test/java/org/elasticsearch/upgrades/TokenBackwardsCompatibilityIT.java
+++ b/x-pack/qa/rolling-upgrade/src/test/java/org/elasticsearch/upgrades/TokenBackwardsCompatibilityIT.java
@@ -13,9 +13,6 @@
 import org.elasticsearch.client.Response;
 import org.elasticsearch.client.ResponseException;
 import org.elasticsearch.client.RestClient;
-import org.elasticsearch.common.Strings;
-import org.elasticsearch.common.xcontent.XContentBuilder;
-import org.elasticsearch.rest.action.document.RestGetAction;
 import org.elasticsearch.test.rest.yaml.ObjectPath;
 
 import java.io.IOException;
@@ -23,32 +20,10 @@
 import java.util.List;
 import java.util.Map;
 
-import static org.elasticsearch.common.xcontent.XContentFactory.jsonBuilder;
-import static org.hamcrest.Matchers.equalTo;
-
 public class TokenBackwardsCompatibilityIT extends AbstractUpgradeTestCase {
 
     public void testGeneratingTokenInOldCluster() throws Exception {
         assumeTrue("this test should only run against the old cluster", CLUSTER_TYPE == ClusterType.OLD);
-        {
-            Version minimumIndexCompatibilityVersion = Version.CURRENT.minimumIndexCompatibilityVersion();
-            assertThat("this branch is not needed if we aren't compatible with 6.0",
-                    minimumIndexCompatibilityVersion.onOrBefore(Version.V_6_0_0), equalTo(true));
-            if (minimumIndexCompatibilityVersion.before(Version.V_7_0_0)) {
-                XContentBuilder template = jsonBuilder();
-                template.startObject();
-                {
-                    template.field("index_patterns", "*");
-                    template.startObject("settings");
-                    template.field("number_of_shards", 5);
-                    template.endObject();
-                }
-                template.endObject();
-                Request createTemplate = new Request("PUT", "/_template/template");
-                createTemplate.setJsonEntity(Strings.toString(template));
-                client().performRequest(createTemplate);
-            }
-        }
 
         Request createTokenRequest = new Request("POST", "/_security/oauth2/token");
         createTokenRequest.setJsonEntity(
@@ -64,7 +39,7 @@ public void testGeneratingTokenInOldCluster() throws Exception {
         assertNotNull(token);
         assertTokenWorks(token);
 
-        Request indexRequest1 = new Request("PUT", "token_backwards_compatibility_it/doc/old_cluster_token1");
+        Request indexRequest1 = new Request("PUT", "token_backwards_compatibility_it/_doc/old_cluster_token1");
         indexRequest1.setJsonEntity(
                 "{\n" +
                 "    \"token\": \"" + token + "\"\n" +
@@ -78,7 +53,7 @@ public void testGeneratingTokenInOldCluster() throws Exception {
         token = (String) responseMap.get("access_token");
         assertNotNull(token);
         assertTokenWorks(token);
-        Request indexRequest2 = new Request("PUT", "token_backwards_compatibility_it/doc/old_cluster_token2");
+        Request indexRequest2 = new Request("PUT", "token_backwards_compatibility_it/_doc/old_cluster_token2");
         indexRequest2.setJsonEntity(
                 "{\n" +
                 "    \"token\": \"" + token + "\"\n" +
@@ -89,8 +64,7 @@ public void testGeneratingTokenInOldCluster() throws Exception {
     public void testTokenWorksInMixedOrUpgradedCluster() throws Exception {
         assumeTrue("this test should only run against the mixed or upgraded cluster",
                 CLUSTER_TYPE == ClusterType.MIXED || CLUSTER_TYPE == ClusterType.UPGRADED);
-        Request getRequest = new Request("GET", "token_backwards_compatibility_it/doc/old_cluster_token1");
-        getRequest.setOptions(expectWarnings(RestGetAction.TYPES_DEPRECATION_MESSAGE));
+        Request getRequest = new Request("GET", "token_backwards_compatibility_it/_doc/old_cluster_token1");
         Response getResponse = client().performRequest(getRequest);
         assertOK(getResponse);
         Map<String, Object> source = (Map<String, Object>) entityAsMap(getResponse).get("_source");
@@ -100,8 +74,7 @@ public void testTokenWorksInMixedOrUpgradedCluster() throws Exception {
     public void testMixedCluster() throws Exception {
         assumeTrue("this test should only run against the mixed cluster", CLUSTER_TYPE == ClusterType.MIXED);
         assumeTrue("the master must be on the latest version before we can write", isMasterOnLatestVersion());
-        Request getRequest = new Request("GET", "token_backwards_compatibility_it/doc/old_cluster_token2");
-        getRequest.setOptions(expectWarnings(RestGetAction.TYPES_DEPRECATION_MESSAGE));
+        Request getRequest = new Request("GET", "token_backwards_compatibility_it/_doc/old_cluster_token2");
 
         Response getResponse = client().performRequest(getRequest);
         Map<String, Object> source = (Map<String, Object>) entityAsMap(getResponse).get("_source");
@@ -152,8 +125,7 @@ public void testMixedCluster() throws Exception {
 
     public void testUpgradedCluster() throws Exception {
         assumeTrue("this test should only run against the mixed cluster", CLUSTER_TYPE == ClusterType.UPGRADED);
-        Request getRequest = new Request("GET", "token_backwards_compatibility_it/doc/old_cluster_token2");
-        getRequest.setOptions(expectWarnings(RestGetAction.TYPES_DEPRECATION_MESSAGE));
+        Request getRequest = new Request("GET", "token_backwards_compatibility_it/_doc/old_cluster_token2");
 
         Response getResponse = client().performRequest(getRequest);
         assertOK(getResponse);
@@ -168,8 +140,7 @@ public void testUpgradedCluster() throws Exception {
         assertOK(invalidationResponse);
         assertTokenDoesNotWork(token);
 
-        getRequest = new Request("GET", "token_backwards_compatibility_it/doc/old_cluster_token1");
-        getRequest.setOptions(expectWarnings(RestGetAction.TYPES_DEPRECATION_MESSAGE));
+        getRequest = new Request("GET", "token_backwards_compatibility_it/_doc/old_cluster_token1");
 
         getResponse = client().performRequest(getRequest);
         source = (Map<String, Object>) entityAsMap(getResponse).get("_source");
diff --git a/x-pack/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/old_cluster/40_ml_datafeed_crud.yml b/x-pack/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/old_cluster/40_ml_datafeed_crud.yml
index bbe26eb69bd20..d7dba6b3b2d3a 100644
--- a/x-pack/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/old_cluster/40_ml_datafeed_crud.yml
+++ b/x-pack/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/old_cluster/40_ml_datafeed_crud.yml
@@ -28,7 +28,6 @@
           {
             "job_id":"old-cluster-datafeed-job",
             "indices":["airline-data"],
-            "types":["response"],
             "scroll_size": 2000
           }