如何激活ActiveMQ持久化以抵抗重启？

Posted 2023-03-10

【中文标题】如何激活ActiveMQ持久化以抵抗重启？

【英文标题】：How to activate ActiveMQ persistence to resist restart?

【发布时间】：2017-08-16 08:31:11

【问题描述】：

我确实得到 ActiveMQ 支持数据持久性 (http://activemq.apache.org/persistence.html)，但我不明白如何使它工作，结果是当我重新启动 ActiveMQ 时，所有消息都消失了，而队列和主题仍然存在。

我已经阅读了有关在数据库上启用持久性的信息，但我想将数据保留在文件系统上，因为我的系统面临数据库性能问题。

这是我的 activemq.xml

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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

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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:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://www.springframework.org/schema/beans 
http://www.springframework.org/schema/beans/spring-beans.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>
<!-- Allows accessing the server log -->
<bean id="logQuery" class="io.fabric8.insight.log.log4j.Log4jLogQuery"
      lazy-init="false" scope="singleton"
      init-method="start" destroy-method="stop">
</bean>

<!--
    The <broker> element is used to configure the ActiveMQ broker.
-->
<broker xmlns="http://activemq.apache.org/schema/core" brokerName="localhost" dataDirectory="$activemq.data">

    <destinationPolicy>
        <policyMap>
          <policyEntries>
            <policyEntry topic=">" >
                <!-- The constantPendingMessageLimitStrategy is used to prevent
                     slow topic consumers to block producers and affect other consumers
                     by limiting the number of messages that are retained
                     For more information, see:

                     http://activemq.apache.org/slow-consumer-handling.html

                -->
              <pendingMessageLimitStrategy>
                <constantPendingMessageLimitStrategy limit="1000"/>
              </pendingMessageLimitStrategy>
            </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 disabling caching and/or slowing down producers. For more information, see:
        http://activemq.apache.org/producer-flow-control.html
      -->
      <systemUsage>
        <systemUsage>
            <memoryUsage>
                <memoryUsage percentOfJvmHeap="70" />
            </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>
        <!-- DOS protection, limit concurrent connections to 1000 and frame size to 100MB -->
        <transportConnector name="openwire" uri="tcp://0.0.0.0:61616?maximumConnections=1000&amp;wireFormat.maxFrameSize=104857600"/>
        <transportConnector name="amqp" uri="amqp://0.0.0.0:5672?maximumConnections=1000&amp;wireFormat.maxFrameSize=104857600"/>
        <transportConnector name="stomp" uri="stomp://0.0.0.0:61613?maximumConnections=1000&amp;wireFormat.maxFrameSize=104857600"/>
        <transportConnector name="mqtt" uri="mqtt://0.0.0.0:1883?maximumConnections=1000&amp;wireFormat.maxFrameSize=104857600"/>
        <transportConnector name="ws" uri="ws://0.0.0.0:61614?maximumConnections=1000&amp;wireFormat.maxFrameSize=104857600"/>
    </transportConnectors>

    <!-- destroy the spring context on shutdown to stop jetty -->
    <shutdownHooks>
        <bean xmlns="http://www.springframework.org/schema/beans" class="org.apache.activemq.hooks.SpringContextHook" />
    </shutdownHooks>

</broker>

<!--
    Enable web consoles, REST and Ajax APIs and demos
    The web consoles requires by default login, you can disable this in the jetty.xml file

    Take a look at $ACTIVEMQ_HOME/conf/jetty.xml for more details
-->
<import resource="jetty.xml"/>

【问题讨论】：

它是否与订阅者必须订阅为持久的事实有关？

能否请您指定用于向队列/主题发送消息的机制

【参考方案1】：

为了在代理上启用持久性，您必须选择一个持久性适配器。您已经通过在 activemq.xml 中指定要使用 KahaDB 来完成此操作。

<broker brokerName="broker" persistent="true" ...>
    <persistenceAdapter>
         <kahaDB directory="$activemq.data/kahadb"/>
    </persistenceAdapter>
</broker>

好的，现在代理知道您要保留传入的消息，但客户端仍然可以覆盖此设置。为此，您需要在发送消息时指定您希望它被保留。检查您用于发送消息的机制，并确保将它们设置为持久化。

例如如果您使用 Spring 的 JmsTemplate 发送消息，则必须致电 setDeliveryPersistent(...)。这只是一个示例，请注意此方法的默认值为 “true”，也就是交付模式“PERSISTENT”。

【参考方案2】：

您还需要持久发送消息。这是客户端决定的事情。在 Java/JMS 中，您将在发送消息时设置 DeliveryMode.PERSISTENT。在其他客户端框架中，例如 MQTT，还有其他方式来指定它，例如 QoS = 1 或 2。

【参考方案3】：

感谢大家，我正在寻找的是为发布者客户端设置服务质量 > 1，因为默认 QoS 是 0。