ARTEMIS-4809 Allow configuring initial queue buffer size

In some setups, there could be a few hundred thousand queues that are
created due to many consumers that are connecting. However, most of
these are empty and stay empty for the entire day since there aren't
necessarily messages to be sent. The 8K intermediateMessageReferences
instantiates an 64KB buffer (Object[]). This means we have large
allocation and live heap that ultimately remains empty for almost the
entire day.

In this commit, we introduce initial-queue-buffer-size, which defaults
to the current value of 8192. It can be set programmatically via
QueueConfiguration#setInitialQueueBufferSize(int).

Note that this must be a positive power of 2.

artemis-core-client/src/main/java/org/apache/activemq/artemis/api/config/ActiveMQDefaultConfiguration.java

@@ -512,6 +512,8 @@ public static String getDefaultHapolicyBackupStrategy() {
 
    public static final long DEFAULT_GLOBAL_MAX_MESSAGES = -1;
 
+   public static final int INITIAL_QUEUE_BUFFER_SIZE = 8192;
+
    public static final int DEFAULT_MAX_DISK_USAGE;
 
    static {
@@ -1967,4 +1969,10 @@ public static boolean getDefaultMirrorPageTransaction() {
       return DEFAULT_MIRROR_PAGE_TRANSACTION;
    }
 
+   /**
+    * the initial size of the intermediate message buffer used for queues
+    */
+   public static int getInitialQueueBufferSize() {
+      return INITIAL_QUEUE_BUFFER_SIZE;
+   }
 }

artemis-core-client/src/main/java/org/apache/activemq/artemis/api/core/management/AddressSettingsInfo.java

@@ -309,6 +309,11 @@ public final class AddressSettingsInfo {
    }
    private boolean enableMetrics;
 
+   static {
+      META_BEAN.add(Integer.class, "initialQueueBufferSize", (t, p) -> t.initialQueueBufferSize = p, t -> t.initialQueueBufferSize);
+   }
+   private int initialQueueBufferSize;
+
 
    public static AddressSettingsInfo fromJSON(final String jsonString) {
       AddressSettingsInfo newInfo = new AddressSettingsInfo();
@@ -554,5 +559,9 @@ public long getMaxExpiryDelay() {
    public boolean isEnableMetrics() {
       return enableMetrics;
    }
+
+   public int getInitialQueueBufferSize() {
+      return initialQueueBufferSize;
+   }
 }
 

artemis-server/src/main/java/org/apache/activemq/artemis/core/config/impl/Validators.java

@@ -107,6 +107,14 @@ public interface Validator<T> {
       }
    };
 
+   public static final Validator<Number> POSITIVE_POWER_OF_TWO = (name, value) -> {
+      if ((value.longValue() & (value.longValue() - 1)) == 0 && value.longValue() > 0) {
+         return value;
+      } else {
+         throw ActiveMQMessageBundle.BUNDLE.positivePowerOfTwo(name, value);
+      }
+   };
+
    public static final Validator<Number> MINUS_ONE_OR_POSITIVE_INT = (name, value) -> {
       if (value.longValue() == -1 || (value.longValue() > 0 && value.longValue() <= Integer.MAX_VALUE)) {
          return value;

artemis-server/src/main/java/org/apache/activemq/artemis/core/deployers/impl/FileConfigurationParser.java

@@ -141,6 +141,7 @@
 import static org.apache.activemq.artemis.core.config.impl.Validators.PERCENTAGE;
 import static org.apache.activemq.artemis.core.config.impl.Validators.PERCENTAGE_OR_MINUS_ONE;
 import static org.apache.activemq.artemis.core.config.impl.Validators.POSITIVE_INT;
+import static org.apache.activemq.artemis.core.config.impl.Validators.POSITIVE_POWER_OF_TWO;
 import static org.apache.activemq.artemis.core.config.impl.Validators.ROUTING_TYPE;
 import static org.apache.activemq.artemis.core.config.impl.Validators.SLOW_CONSUMER_POLICY_TYPE;
 import static org.apache.activemq.artemis.core.config.impl.Validators.SLOW_CONSUMER_THRESHOLD_MEASUREMENT_UNIT;
@@ -388,6 +389,8 @@ public final class FileConfigurationParser extends XMLConfigurationUtil {
 
    private static final String MIRROR_PAGE_TRANSACTION = "mirror-page-transaction";
 
+   private static final String INITIAL_QUEUE_BUFFER_SIZE = "initial-queue-buffer-size";
+
    private boolean validateAIO = false;
 
    private boolean printPageMaxSizeUsed = false;
@@ -1472,6 +1475,8 @@ protected Pair<String, AddressSettings> parseAddressSettings(final Node node) {
             addressSettings.setEnableIngressTimestamp(XMLUtil.parseBoolean(child));
          } else if (ID_CACHE_SIZE.equalsIgnoreCase(name)) {
             addressSettings.setIDCacheSize(GE_ZERO.validate(ID_CACHE_SIZE, XMLUtil.parseInt(child)).intValue());
+         } else if (INITIAL_QUEUE_BUFFER_SIZE.equalsIgnoreCase(name)) {
+            addressSettings.setInitialQueueBufferSize(POSITIVE_POWER_OF_TWO.validate(INITIAL_QUEUE_BUFFER_SIZE, XMLUtil.parseInt(child)).intValue());
          }
       }
       return setting;

artemis-server/src/main/java/org/apache/activemq/artemis/core/server/ActiveMQMessageBundle.java

@@ -559,4 +559,6 @@ IllegalStateException invalidRoutingTypeUpdate(String queueName,
    @Message(id = 229255, value = "Bridge {} cannot be {}. Current state: {}")
    ActiveMQIllegalStateException bridgeOperationCannotBeExecuted(String bridgeName, String failedOp, BridgeImpl.State currentState);
 
+   @Message(id = 229256, value = "{} must be a positive power of 2 (actual value: {})")
+   IllegalArgumentException positivePowerOfTwo(String name, Number val);
 }

artemis-server/src/main/java/org/apache/activemq/artemis/core/server/Queue.java

@@ -178,6 +178,8 @@ default void setSwept(boolean sweep) {
 
    long getRingSize();
 
+   int getInitialQueueBufferSize();
+
    default boolean isMirrorController() {
       return false;
    }

artemis-server/src/main/java/org/apache/activemq/artemis/core/server/impl/QueueImpl.java

@@ -213,7 +213,7 @@ public class QueueImpl extends CriticalComponentImpl implements Queue {
    // Messages will first enter intermediateMessageReferences
    // Before they are added to messageReferences
    // This is to avoid locking the queue on the producer
-   private final MpscUnboundedArrayQueue<MessageReference> intermediateMessageReferences = new MpscUnboundedArrayQueue<>(8192);
+   private final MpscUnboundedArrayQueue<MessageReference> intermediateMessageReferences;
 
    // This is where messages are stored
    protected final PriorityLinkedList<MessageReference> messageReferences = new PriorityLinkedListImpl<>(QueueImpl.NUM_PRIORITIES, MessageReferenceImpl.getSequenceComparator());
@@ -365,6 +365,8 @@ private void checkIDSupplier(NodeStoreFactory<MessageReference> nodeStoreFactory
 
    private volatile long createdTimestamp = -1;
 
+   private final int initialQueueBufferSize;
+
    @Override
    public boolean isSwept() {
       return swept;
@@ -753,6 +755,11 @@ public QueueImpl(final QueueConfiguration queueConfiguration,
       }
 
       this.ringSize = queueConfiguration.getRingSize() == null ? ActiveMQDefaultConfiguration.getDefaultRingSize() : queueConfiguration.getRingSize();
+
+      this.initialQueueBufferSize = this.addressSettings.getInitialQueueBufferSize() == null
+              ? ActiveMQDefaultConfiguration.INITIAL_QUEUE_BUFFER_SIZE
+              : this.addressSettings.getInitialQueueBufferSize();
+      this.intermediateMessageReferences = new MpscUnboundedArrayQueue<>(initialQueueBufferSize);
    }
 
    // Bindable implementation -------------------------------------------------------------------------------------
@@ -1092,6 +1099,11 @@ public RoutingType getRoutingType() {
       return routingType;
    }
 
+   @Override
+   public int getInitialQueueBufferSize() {
+      return this.initialQueueBufferSize;
+   }
+
    @Override
    public void setRoutingType(RoutingType routingType) {
       if (addressInfo.getRoutingTypes().contains(routingType)) {

artemis-server/src/main/java/org/apache/activemq/artemis/core/settings/impl/AddressSettings.java

@@ -533,6 +533,12 @@ public class AddressSettings implements Mergeable<AddressSettings>, Serializable
    static {
       metaBean.add(Integer.class, "queuePrefetch", (t, p) -> t.queuePrefetch = p, t -> t.queuePrefetch);
    }
+
+   static {
+      metaBean.add(Integer.class, "initialQueueBufferSize", (t, p) -> t.initialQueueBufferSize = p, t -> t.initialQueueBufferSize);
+   }
+   private Integer initialQueueBufferSize = null;
+
    //from amq5
    //make it transient
    @Deprecated
@@ -1283,6 +1289,15 @@ public AddressSettings setIDCacheSize(int idCacheSize) {
       return this;
    }
 
+   public Integer getInitialQueueBufferSize() {
+      return initialQueueBufferSize;
+   }
+
+   public AddressSettings setInitialQueueBufferSize(int initialQueueBufferSize) {
+      this.initialQueueBufferSize = initialQueueBufferSize;
+      return this;
+   }
+
    /**
     * Merge two AddressSettings instances in one instance
     *
@@ -1783,6 +1798,9 @@ public boolean equals(Object o) {
          return false;
       if (!Objects.equals(idCacheSize, that.idCacheSize))
          return false;
+      if (!Objects.equals(initialQueueBufferSize, that.initialQueueBufferSize)) {
+         return false;
+      }
       return Objects.equals(queuePrefetch, that.queuePrefetch);
    }
 
@@ -1865,11 +1883,13 @@ public int hashCode() {
       result = 31 * result + (enableIngressTimestamp != null ? enableIngressTimestamp.hashCode() : 0);
       result = 31 * result + (idCacheSize != null ? idCacheSize.hashCode() : 0);
       result = 31 * result + (queuePrefetch != null ? queuePrefetch.hashCode() : 0);
+      result = 31 * result + (initialQueueBufferSize != null ? initialQueueBufferSize.hashCode() : 0);
       return result;
    }
 
    @Override
    public String toString() {
-      return "AddressSettings{" + "addressFullMessagePolicy=" + addressFullMessagePolicy + ", maxSizeBytes=" + maxSizeBytes + ", maxReadPageBytes=" + maxReadPageBytes + ", maxReadPageMessages=" + maxReadPageMessages + ", prefetchPageBytes=" + prefetchPageBytes + ", prefetchPageMessages=" + prefetchPageMessages + ", pageLimitBytes=" + pageLimitBytes + ", pageLimitMessages=" + pageLimitMessages + ", pageFullMessagePolicy=" + pageFullMessagePolicy + ", maxSizeMessages=" + maxSizeMessages + ", pageSizeBytes=" + pageSizeBytes + ", pageMaxCache=" + pageCacheMaxSize + ", dropMessagesWhenFull=" + dropMessagesWhenFull + ", maxDeliveryAttempts=" + maxDeliveryAttempts + ", messageCounterHistoryDayLimit=" + messageCounterHistoryDayLimit + ", redeliveryDelay=" + redeliveryDelay + ", redeliveryMultiplier=" + redeliveryMultiplier + ", redeliveryCollisionAvoidanceFactor=" + redeliveryCollisionAvoidanceFactor + ", maxRedeliveryDelay=" + maxRedeliveryDelay + ", deadLetterAddress=" + deadLetterAddress + ", expiryAddress=" + expiryAddress + ", expiryDelay=" + expiryDelay + ", minExpiryDelay=" + minExpiryDelay + ", maxExpiryDelay=" + maxExpiryDelay + ", defaultLastValueQueue=" + defaultLastValueQueue + ", defaultLastValueKey=" + defaultLastValueKey + ", defaultNonDestructive=" + defaultNonDestructive + ", defaultExclusiveQueue=" + defaultExclusiveQueue + ", defaultGroupRebalance=" + defaultGroupRebalance + ", defaultGroupRebalancePauseDispatch=" + defaultGroupRebalancePauseDispatch + ", defaultGroupBuckets=" + defaultGroupBuckets + ", defaultGroupFirstKey=" + defaultGroupFirstKey + ", redistributionDelay=" + redistributionDelay + ", sendToDLAOnNoRoute=" + sendToDLAOnNoRoute + ", slowConsumerThreshold=" + slowConsumerThreshold + ", slowConsumerThresholdMeasurementUnit=" + slowConsumerThresholdMeasurementUnit + ", slowConsumerCheckPeriod=" + slowConsumerCheckPeriod + ", slowConsumerPolicy=" + slowConsumerPolicy + ", autoCreateJmsQueues=" + autoCreateJmsQueues + ", autoDeleteJmsQueues=" + autoDeleteJmsQueues + ", autoCreateJmsTopics=" + autoCreateJmsTopics + ", autoDeleteJmsTopics=" + autoDeleteJmsTopics + ", autoCreateQueues=" + autoCreateQueues + ", autoDeleteQueues=" + autoDeleteQueues + ", autoDeleteCreatedQueues=" + autoDeleteCreatedQueues + ", autoDeleteQueuesDelay=" + autoDeleteQueuesDelay + ", autoDeleteQueuesSkipUsageCheck=" + autoDeleteQueuesSkipUsageCheck + ", autoDeleteQueuesMessageCount=" + autoDeleteQueuesMessageCount + ", defaultRingSize=" + defaultRingSize + ", retroactiveMessageCount=" + retroactiveMessageCount + ", configDeleteQueues=" + configDeleteQueues + ", autoCreateAddresses=" + autoCreateAddresses + ", autoDeleteAddresses=" + autoDeleteAddresses + ", autoDeleteAddressesDelay=" + autoDeleteAddressesDelay + ", autoDeleteAddressesSkipUsageCheck=" + autoDeleteAddressesSkipUsageCheck + ", configDeleteAddresses=" + configDeleteAddresses + ", configDeleteDiverts=" + configDeleteDiverts + ", managementBrowsePageSize=" + managementBrowsePageSize + ", maxSizeBytesRejectThreshold=" + maxSizeBytesRejectThreshold + ", defaultMaxConsumers=" + defaultMaxConsumers + ", defaultPurgeOnNoConsumers=" + defaultPurgeOnNoConsumers + ", defaultConsumersBeforeDispatch=" + defaultConsumersBeforeDispatch + ", defaultDelayBeforeDispatch=" + defaultDelayBeforeDispatch + ", defaultQueueRoutingType=" + defaultQueueRoutingType + ", defaultAddressRoutingType=" + defaultAddressRoutingType + ", defaultConsumerWindowSize=" + defaultConsumerWindowSize + ", autoCreateDeadLetterResources=" + autoCreateDeadLetterResources + ", deadLetterQueuePrefix=" + deadLetterQueuePrefix + ", deadLetterQueueSuffix=" + deadLetterQueueSuffix + ", autoCreateExpiryResources=" + autoCreateExpiryResources + ", expiryQueuePrefix=" + expiryQueuePrefix + ", expiryQueueSuffix=" + expiryQueueSuffix + ", enableMetrics=" + enableMetrics + ", managementMessageAttributeSizeLimit=" + managementMessageAttributeSizeLimit + ", enableIngressTimestamp=" + enableIngressTimestamp + ", idCacheSize=" + idCacheSize + ", queuePrefetch=" + queuePrefetch + '}';
+      return "AddressSettings{" + "addressFullMessagePolicy=" + addressFullMessagePolicy + ", maxSizeBytes=" + maxSizeBytes + ", maxReadPageBytes=" + maxReadPageBytes + ", maxReadPageMessages=" + maxReadPageMessages + ", prefetchPageBytes=" + prefetchPageBytes + ", prefetchPageMessages=" + prefetchPageMessages + ", pageLimitBytes=" + pageLimitBytes + ", pageLimitMessages=" + pageLimitMessages + ", pageFullMessagePolicy=" + pageFullMessagePolicy + ", maxSizeMessages=" + maxSizeMessages + ", pageSizeBytes=" + pageSizeBytes + ", pageMaxCache=" + pageCacheMaxSize + ", dropMessagesWhenFull=" + dropMessagesWhenFull + ", maxDeliveryAttempts=" + maxDeliveryAttempts + ", messageCounterHistoryDayLimit=" + messageCounterHistoryDayLimit + ", redeliveryDelay=" + redeliveryDelay + ", redeliveryMultiplier=" + redeliveryMultiplier + ", redeliveryCollisionAvoidanceFactor=" + redeliveryCollisionAvoidanceFactor + ", maxRedeliveryDelay=" + maxRedeliveryDelay + ", deadLetterAddress=" + deadLetterAddress + ", expiryAddress=" + expiryAddress + ", expiryDelay=" + expiryDelay + ", minExpiryDelay=" + minExpiryDelay + ", maxExpiryDelay=" + maxExpiryDelay + ", defaultLastValueQueue=" + defaultLastValueQueue + ", defaultLastValueKey=" + defaultLastValueKey + ", defaultNonDestructive=" + defaultNonDestructive + ", defaultExclusiveQueue=" + defaultExclusiveQueue + ", defaultGroupRebalance=" + defaultGroupRebalance + ", defaultGroupRebalancePauseDispatch=" + defaultGroupRebalancePauseDispatch + ", defaultGroupBuckets=" + defaultGroupBuckets + ", defaultGroupFirstKey=" + defaultGroupFirstKey + ", redistributionDelay=" + redistributionDelay + ", sendToDLAOnNoRoute=" + sendToDLAOnNoRoute + ", slowConsumerThreshold=" + slowConsumerThreshold + ", slowConsumerThresholdMeasurementUnit=" + slowConsumerThresholdMeasurementUnit + ", slowConsumerCheckPeriod=" + slowConsumerCheckPeriod + ", slowConsumerPolicy=" + slowConsumerPolicy + ", autoCreateJmsQueues=" + autoCreateJmsQueues + ", autoDeleteJmsQueues=" + autoDeleteJmsQueues + ", autoCreateJmsTopics=" + autoCreateJmsTopics + ", autoDeleteJmsTopics=" + autoDeleteJmsTopics + ", autoCreateQueues=" + autoCreateQueues + ", autoDeleteQueues=" + autoDeleteQueues + ", autoDeleteCreatedQueues=" + autoDeleteCreatedQueues + ", autoDeleteQueuesDelay=" + autoDeleteQueuesDelay + ", autoDeleteQueuesSkipUsageCheck=" + autoDeleteQueuesSkipUsageCheck + ", autoDeleteQueuesMessageCount=" + autoDeleteQueuesMessageCount + ", defaultRingSize=" + defaultRingSize + ", retroactiveMessageCount=" + retroactiveMessageCount + ", configDeleteQueues=" + configDeleteQueues + ", autoCreateAddresses=" + autoCreateAddresses + ", autoDeleteAddresses=" + autoDeleteAddresses + ", autoDeleteAddressesDelay=" + autoDeleteAddressesDelay + ", autoDeleteAddressesSkipUsageCheck=" + autoDeleteAddressesSkipUsageCheck + ", configDeleteAddresses=" + configDeleteAddresses + ", configDeleteDiverts=" + configDeleteDiverts + ", managementBrowsePageSize=" + managementBrowsePageSize + ", maxSizeBytesRejectThreshold=" + maxSizeBytesRejectThreshold + ", defaultMaxConsumers=" + defaultMaxConsumers + ", defaultPurgeOnNoConsumers=" + defaultPurgeOnNoConsumers + ", defaultConsumersBeforeDispatch=" + defaultConsumersBeforeDispatch + ", defaultDelayBeforeDispatch=" + defaultDelayBeforeDispatch + ", defaultQueueRoutingType=" + defaultQueueRoutingType + ", defaultAddressRoutingType=" + defaultAddressRoutingType + ", defaultConsumerWindowSize=" + defaultConsumerWindowSize + ", autoCreateDeadLetterResources=" + autoCreateDeadLetterResources + ", deadLetterQueuePrefix=" + deadLetterQueuePrefix + ", deadLetterQueueSuffix=" + deadLetterQueueSuffix + ", autoCreateExpiryResources=" + autoCreateExpiryResources + ", expiryQueuePrefix=" + expiryQueuePrefix + ", expiryQueueSuffix=" + expiryQueueSuffix + ", enableMetrics=" + enableMetrics + ", managementMessageAttributeSizeLimit=" + managementMessageAttributeSizeLimit + ", enableIngressTimestamp=" + enableIngressTimestamp + ", idCacheSize=" + idCacheSize + ", queuePrefetch=" + queuePrefetch + ", initialQueueBufferSize=" + initialQueueBufferSize
+             + '}';
    }
 }

artemis-server/src/main/resources/schema/artemis-configuration.xsd

@@ -4465,6 +4465,15 @@
             </xsd:annotation>
          </xsd:element>
 
+         <xsd:element name="initial-queue-buffer-size" default="8192" type="xsd:int" maxOccurs="1" minOccurs="0">
+            <xsd:annotation>
+               <xsd:documentation>
+                  This will set the initial intermediate message reference buffer size for all queues on the matching address. Will use the
+                  default initial size if not configured.
+               </xsd:documentation>
+            </xsd:annotation>
+         </xsd:element>
+
       </xsd:all>
 
       <xsd:attribute name="match" type="xsd:string" use="required">

artemis-server/src/test/java/org/apache/activemq/artemis/core/config/impl/FileConfigurationTest.java

@@ -534,6 +534,7 @@ public void testFileConfiguration() {
       assertTrue(conf.getAddressSettings().get("a1").isEnableMetrics());
       assertTrue(conf.getAddressSettings().get("a1").isEnableIngressTimestamp());
       assertNull(conf.getAddressSettings().get("a1").getIDCacheSize());
+      assertNull(conf.getAddressSettings().get("a1").getInitialQueueBufferSize());
 
       assertEquals("a2.1", conf.getAddressSettings().get("a2").getDeadLetterAddress().toString());
       assertTrue(conf.getAddressSettings().get("a2").isAutoCreateDeadLetterResources());
@@ -575,6 +576,7 @@ public void testFileConfiguration() {
       assertFalse(conf.getAddressSettings().get("a2").isEnableMetrics());
       assertFalse(conf.getAddressSettings().get("a2").isEnableIngressTimestamp());
       assertEquals(Integer.valueOf(500), conf.getAddressSettings().get("a2").getIDCacheSize());
+      assertEquals(Integer.valueOf(128), conf.getAddressSettings().get("a2").getInitialQueueBufferSize());
 
       assertEquals(111, conf.getMirrorAckManagerQueueAttempts());
       assertEquals(222, conf.getMirrorAckManagerPageAttempts());

artemis-server/src/test/java/org/apache/activemq/artemis/core/config/impl/ValidatorsTest.java

@@ -152,4 +152,16 @@ public void testTWO_CHARACTERS() {
       ValidatorsTest.success(Validators.NULL_OR_TWO_CHARACTERS, null);
    }
 
+   @Test
+   public void testPOSITIVE_POWER_OF_TWO() {
+      ValidatorsTest.failure(Validators.POSITIVE_POWER_OF_TWO, 0);
+      ValidatorsTest.failure(Validators.POSITIVE_POWER_OF_TWO, -10);
+      ValidatorsTest.failure(Validators.POSITIVE_POWER_OF_TWO, 127);
+
+      ValidatorsTest.success(Validators.POSITIVE_POWER_OF_TWO, 2);
+      ValidatorsTest.success(Validators.POSITIVE_POWER_OF_TWO, 64);
+      ValidatorsTest.success(Validators.POSITIVE_POWER_OF_TWO, 1024);
+      ValidatorsTest.success(Validators.POSITIVE_POWER_OF_TWO, 16777216);
+   }
+
 }

artemis-server/src/test/java/org/apache/activemq/artemis/core/server/impl/RoutingContextTest.java

@@ -378,6 +378,11 @@ public long getRingSize() {
          return 0;
       }
 
+      @Override
+      public int getInitialQueueBufferSize() {
+         return 0;
+      }
+
       @Override
       public ReferenceCounter getConsumersRefCount() {
          return null;

artemis-server/src/test/java/org/apache/activemq/artemis/core/server/impl/ScheduledDeliveryHandlerTest.java

@@ -1717,5 +1717,10 @@ public boolean isExclusive() {
       public void setExclusive(boolean exclusive) {
 
       }
+
+      @Override
+      public int getInitialQueueBufferSize() {
+         return 0;
+      }
    }
 }

artemis-server/src/test/java/org/apache/activemq/artemis/core/settings/AddressSettingsTest.java

@@ -92,6 +92,7 @@ private void testSingleMerge(boolean copy) {
       addressSettingsToMerge.setMinExpiryDelay(888L);
       addressSettingsToMerge.setMaxExpiryDelay(777L);
       addressSettingsToMerge.setIDCacheSize(5);
+      addressSettingsToMerge.setInitialQueueBufferSize(256);
 
       if (copy) {
          addressSettings = addressSettings.mergeCopy(addressSettingsToMerge);
@@ -113,6 +114,7 @@ private void testSingleMerge(boolean copy) {
       assertEquals(Long.valueOf(888), addressSettings.getMinExpiryDelay());
       assertEquals(Long.valueOf(777), addressSettings.getMaxExpiryDelay());
       assertEquals(Integer.valueOf(5), addressSettings.getIDCacheSize());
+      assertEquals(Integer.valueOf(256), addressSettings.getInitialQueueBufferSize());
    }
 
    @Test

artemis-server/src/test/resources/ConfigurationTest-full-config.xml

@@ -639,6 +639,7 @@
             <management-browse-page-size>400</management-browse-page-size>
             <management-message-attribute-size-limit>265</management-message-attribute-size-limit>
             <id-cache-size>500</id-cache-size>
+            <initial-queue-buffer-size>128</initial-queue-buffer-size>
          </address-setting>
       </address-settings>
       <resource-limit-settings>