我们最近从ActiveMQ 4.0迁移到ActiveMQ 5.6，并注意到代理的响应时间减慢了大约50-60秒。我们使用的是默认的ActiveMQ 5.6设置，并且没有配置任何参数。客户端使用Java Impl存根，应用服务器是Jboss 5.1.0。我们打开了ActiveMQ中的TRACE日志记录，以检查减速的原因，但无法找到任何重要信息。队列看起来好像在等待某些原因，我们可以在日志中看到很多以下的行重复：
2012-06-11 02:04:38,523 | DEBUG | queue://dav/validator expiring messages .. | org.apache.activemq.broker.region.Queue | ActiveMQ Broker[localhost] Scheduler
2012-06-11 02:04:38,524 | DEBUG | dav/validator toPageIn: 0, Inflight: 0, pagedInMessages.size 0, enqueueCount: 0, dequeueCount: 0 | org.apache.activemq.broker.region.Queue | ActiveMQ Broker[localhost] Scheduler
2012-06-11 02:04:38,524 | TRACE | org.apache.activemq.broker.region.cursors.QueueStorePrefetch@e0420b:dav/validator,batchResetNeeded=false,storeHasMessages=false,size=0,cacheEnabled=true - fillBatch | org.apache.activemq.broker.region.cursors.AbstractStoreCursor | ActiveMQ Broker[localhost] Scheduler
2012-06-11 02:04:38,524 | TRACE | org.apache.activemq.broker.region.cursors.QueueStorePrefetch@e0420b:dav/validator,batchResetNeeded=false,storeHasMessages=false,size=0,cacheEnabled=true - fillBatch | org.apache.activemq.broker.region.cursors.AbstractStoreCursor | ActiveMQ Broker[localhost] Scheduler
2012-06-11 02:04:38,524 | DEBUG | queue://dav/validator expiring messages done. | org.apache.activemq.broker.region.Queue | ActiveMQ Broker[localhost] Scheduler
2012-06-11 02:04:39,824 | DEBUG | queue://dav/logger expiring messages .. | org.apache.activemq.broker.region.Queue | ActiveMQ Broker[localhost] Scheduler
2012-06-11 02:04:39,824 | DEBUG | dav/logger toPageIn: 0, Inflight: 0, pagedInMessages.size 0, enqueueCount: 1, dequeueCount: 1 | org.apache.activemq.broker.region.Queue | ActiveMQ Broker[localhost] Scheduler
2012-06-11 02:04:39,824 | TRACE | org.apache.activemq.broker.region.cursors.QueueStorePrefetch@1c64ed8:dav/logger,batchResetNeeded=false,storeHasMessages=true,size=0,cacheEnabled=true - fillBatch | org.apache.activemq.broker.region.cursors.AbstractStoreCursor | ActiveMQ Broker[localhost] Scheduler
2012-06-11 02:04:39,824 | TRACE | org.apache.activemq.broker.region.cursors.QueueStorePrefetch@1c64ed8:dav/logger,batchResetNeeded=false,storeHasMessages=true,size=0,cacheEnabled=true - fillBatch | org.apache.activemq.broker.region.cursors.AbstractStoreCursor | ActiveMQ Broker[localhost] Scheduler
2012-06-11 02:04:39,824 | DEBUG | queue://dav/logger expiring messages done. | org.apache.activemq.broker.region.Queue | ActiveMQ Broker[localhost] Scheduler
2012-06-11 02:04:39,824 | DEBUG | queue://dav/synchronizer expiring messages .. | org.apache.activemq.broker.region.Queue | ActiveMQ Broker[localhost] Scheduler
2012-06-11 02:04:39,824 | DEBUG | dav/synchronizer toPageIn: 0, Inflight: 0, pagedInMessages.size 0, enqueueCount: 1, dequeueCount: 1 | org.apache.activemq.broker.region.Queue | ActiveMQ Broker[localhost] Scheduler
2012-06-11 02:04:39,824 | TRACE | org.apache.activemq.broker.region.cursors.QueueStorePrefetch@1549ceb:dav/synchronizer,batchResetNeeded=false,storeHasMessages=true,size=0,cacheEnabled=true - fillBatch | org.apache.activemq.broker.region.cursors.AbstractStoreCursor | ActiveMQ Broker[localhost] Scheduler
2012-06-11 02:04:39,825 | TRACE | org.apache.activemq.broker.region.cursors.QueueStorePrefetch@1549ceb:dav/synchronizer,batchResetNeeded=false,storeHasMessages=true,size=0,cacheEnabled=true - fillBatch | org.apache.activemq.broker.region.cursors.AbstractStoreCursor | ActiveMQ Broker[localhost] Scheduler
2012-06-11 02:04:39,825 | DEBUG | queue://dav/synchronizer expiring messages done. | org.apache.activemq.broker.region.Queue | ActiveMQ Broker[localhost] Scheduler
2012-06-11 02:04:39,825 | DEBUG | queue://dav/executor expiring messages .. | org.apache.activemq.broker.region.Queue | ActiveMQ Broker[localhost] Scheduler
2012-06-11 02:04:39,825 | DEBUG | dav/executor toPageIn: 0, Inflight: 0, pagedInMessages.size 0, enqueueCount: 1, dequeueCount: 1 | org.apache.activemq.broker.region.Queue | ActiveMQ Broker[localhost] Scheduler
2012-06-11 02:04:39,825 | TRACE | org.apache.activemq.broker.region.cursors.QueueStorePrefetch@9b777a:dav/executor,batchResetNeeded=false,storeHasMessages=true,size=0,cacheEnabled=true - fillBatch | org.apache.activemq.broker.region.cursors.AbstractStoreCursor | ActiveMQ Broker[localhost] Scheduler
2012-06-11 02:04:39,825 | TRACE | org.apache.activemq.broker.region.cursors.QueueStorePrefetch@9b777a:dav/executor,batchResetNeeded=false,storeHasMessages=true,size=0,cacheEnabled=true - fillBatch | org.apache.activemq.broker.region.cursors.AbstractStoreCursor | ActiveMQ Broker[localhost] Scheduler
我们可以从调度程序中看到上面的行，并怀疑它可能正在引入等待，因此尝试使用标志useScheduleSupport = false。我们还尝试了persistent = false标志，但它对时间没有影响。
这是我的ActiveMQ.xml文件：
<!--
Licensed to the Apache Software Foundation (ASF) under one or more
contributor license agreements. See the NOTICE file distributed with
this work for additional information regarding copyright ownership.
The ASF licenses this file to You under the Apache License, Version 2.0
(the "License"); you may not use this file except in compliance with
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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.
-->
<!-- START SNIPPET: example -->
<beans
xmlns="http://www.springframework.org/schema/beans"
xmlns:amq="http://activemq.apache.org/schema/core"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
http://activemq.apache.org/schema/core http://activemq.apache.org/schema/core/activemq-core.xsd">
<!-- Allows us to use system properties as variables in this configuration file -->
<bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations">
<value>file:${activemq.conf}/credentials.properties</value>
</property>
</bean>
<!--
The <broker> element is used to configure the ActiveMQ broker.
-->
<broker xmlns="http://activemq.apache.org/schema/core" brokerName="localhost" dataDirectory="${activemq.data}"
useShutdownHook="false" useJmx="true" persistent="false">
<!--
For better performances use VM cursor and small memory limit.
For more information, see:
http://activemq.apache.org/message-cursors.html
Also, if your producer is "hanging", it's probably due to producer flow control.
For more information, see:
http://activemq.apache.org/producer-flow-control.html
-->
<!--
<destinationPolicy>
<policyMap><policyEntries>
<policyEntry topic="FOO.>">
<dispatchPolicy>
<strictOrderDispatchPolicy />
</dispatchPolicy>
<subscriptionRecoveryPolicy>
<lastImageSubscriptionRecoveryPolicy />
</subscriptionRecoveryPolicy>
</policyEntry>
</policyEntries></policyMap>
</destinationPolicy>
-->
<destinationPolicy>
<policyMap>
<policyEntries>
<policyEntry topic=">" producerFlowControl="false" memoryLimit="1mb">
<pendingSubscriberPolicy>
<vmCursor />
</pendingSubscriberPolicy>
</policyEntry>
<policyEntry queue=">" producerFlowControl="false" memoryLimit="1mb">
<!-- Use VM cursor for better latency
For more information, see:
http://activemq.apache.org/message-cursors.html
<pendingQueuePolicy>
<vmQueueCursor/>
</pendingQueuePolicy>
-->
</policyEntry>
</policyEntries>
</policyMap>
</destinationPolicy>
<!--
The managementContext is used to configure how ActiveMQ is exposed in
JMX. By default, ActiveMQ uses the MBean server that is started by
the JVM. For more information, see:
http://activemq.apache.org/jmx.html
-->
<managementContext>
<managementContext createConnector="false"/>
</managementContext>
<!--
Configure message persistence for the broker. The default persistence
mechanism is the KahaDB store (identified by the kahaDB tag).
For more information, see:
http://activemq.apache.org/persistence.html
-->
<persistenceAdapter>
<kahaDB directory="${activemq.data}/kahadb"/>
</persistenceAdapter>
<!--
The systemUsage controls the maximum amount of space the broker will
use before slowing down producers. For more information, see:
http://activemq.apache.org/producer-flow-control.html
If using ActiveMQ embedded - the following limits could safely be used:
<systemUsage>
<systemUsage>
<memoryUsage>
<memoryUsage limit="20 mb"/>
</memoryUsage>
<storeUsage>
<storeUsage limit="1 gb"/>
</storeUsage>
<tempUsage>
<tempUsage limit="100 mb"/>
</tempUsage>
</systemUsage>
</systemUsage>
<systemUsage>
<systemUsage>
<memoryUsage>
<memoryUsage limit="64 mb"/>
</memoryUsage>
<storeUsage>
<storeUsage limit="100 gb"/>
</storeUsage>
<tempUsage>
<tempUsage limit="50 gb"/>
</tempUsage>
</systemUsage>
</systemUsage>-->
<!--
The transport connectors expose ActiveMQ over a given protocol to
clients and other brokers. For more information, see:
http://activemq.apache.org/configuring-transports.html
-->
<transportConnectors>
<transportConnector name="default" uri="tcp://localhost:61616?jms.useAsyncSend=true&jms.prefetchPolicy.all=10&wireFormat.maxInactivityDuration=0" discoveryUri="multicast://default"/>
</transportConnectors>
请帮助理解可能是响应中额外延迟的根本原因。这个额外的响应时间导致我们的生产标准响应时间限制失败。此外，客户端超时等待数据，因为它们被配置为在达到时间限制后自动关闭连接。