1.2. 了解默认代理配置

您可以通过编辑 broker.xml 配置文件来配置大多数代理的功能。此文件包含默认设置，这足以启动和操作代理。但是，您可能需要更改一些默认设置，并添加新设置来为您的环境配置代理。

默认情况下，broker.xml 包含以下功能的默认设置：

默认消息持久性设置

默认情况下，AMQ Broker 持久性使用由磁盘上一组文件组成的只附加文件日志。日志会保存消息、事务和其他信息。

<configuration ...>

   <core ...>

      ...

      <persistence-enabled>true</persistence-enabled>

      <!-- this could be ASYNCIO, MAPPED, NIO
           ASYNCIO: Linux Libaio
           MAPPED: mmap files
           NIO: Plain Java Files
       -->
      <journal-type>ASYNCIO</journal-type>

      <paging-directory>data/paging</paging-directory>

      <bindings-directory>data/bindings</bindings-directory>

      <journal-directory>data/journal</journal-directory>

      <large-messages-directory>data/large-messages</large-messages-directory>

      <journal-datasync>true</journal-datasync>

      <journal-min-files>2</journal-min-files>

      <journal-pool-files>10</journal-pool-files>

      <journal-file-size>10M</journal-file-size>

      <!--
       This value was determined through a calculation.
       Your system could perform 8.62 writes per millisecond
       on the current journal configuration.
       That translates as a sync write every 115999 nanoseconds.

       Note: If you specify 0 the system will perform writes directly to the disk.
             We recommend this to be 0 if you are using journalType=MAPPED and journal-datasync=false.
      -->
      <journal-buffer-timeout>115999</journal-buffer-timeout>

      <!--
        When using ASYNCIO, this will determine the writing queue depth for libaio.
       -->
      <journal-max-io>4096</journal-max-io>

      <!-- how often we are looking for how many bytes are being used on the disk in ms -->
      <disk-scan-period>5000</disk-scan-period>

      <!-- once the disk hits this limit the system will block, or close the connection in certain protocols
           that won't support flow control. -->
      <max-disk-usage>90</max-disk-usage>

      <!-- should the broker detect dead locks and other issues -->
      <critical-analyzer>true</critical-analyzer>

      <critical-analyzer-timeout>120000</critical-analyzer-timeout>

      <critical-analyzer-check-period>60000</critical-analyzer-check-period>

      <critical-analyzer-policy>HALT</critical-analyzer-policy>

      ...

  </core>

</configuration>

默认接受器设置

代理通过使用 acceptor configuration 元素侦听传入的客户端连接，以定义客户端可用于建立连接的端口和协议。默认情况下，AMQ Broker 包括每个支持的消息传递协议的接收器，如下所示。

<configuration ...>

   <core ...>

      ...

      <acceptors>

        <!-- Acceptor for every supported protocol -->
        <acceptor name="artemis">tcp://0.0.0.0:61616?tcpSendBufferSize=1048576;tcpReceiveBufferSize=1048576;protocols=CORE,AMQP,STOMP,HORNETQ,MQTT,OPENWIRE;useEpoll=true;amqpCredits=1000;amqpLowCredits=300</acceptor>

        <!-- AMQP Acceptor. Listens on default AMQP port for AMQP traffic -->
        <acceptor name="amqp">tcp://0.0.0.0:5672?tcpSendBufferSize=1048576;tcpReceiveBufferSize=1048576;protocols=AMQP;useEpoll=true;amqpCredits=1000;amqpLowCredits=300</acceptor>

        <!-- STOMP Acceptor -->
        <acceptor name="stomp">tcp://0.0.0.0:61613?tcpSendBufferSize=1048576;tcpReceiveBufferSize=1048576;protocols=STOMP;useEpoll=true</acceptor>

        <!-- HornetQ Compatibility Acceptor. Enables HornetQ Core and STOMP for legacy HornetQ clients. -->
        <acceptor name="hornetq">tcp://0.0.0.0:5445?anycastPrefix=jms.queue.;multicastPrefix=jms.topic.;protocols=HORNETQ,STOMP;useEpoll=true</acceptor>

        <!-- MQTT Acceptor -->
        <acceptor name="mqtt">tcp://0.0.0.0:1883?tcpSendBufferSize=1048576;tcpReceiveBufferSize=1048576;protocols=MQTT;useEpoll=true</acceptor>

      </acceptors>

      ...

  </core>

</configuration>

默认安全设置

AMQ Broker 包含一个灵活的基于角色的访问控制，根据其地址将安全性应用到队列。默认配置使用通配符将 amq 角色应用到所有地址（以数字符号 # 表示）。

<configuration ...>

   <core ...>

      ...

      <security-settings>
         <security-setting match="#">
            <permission type="createNonDurableQueue" roles="amq"/>
            <permission type="deleteNonDurableQueue" roles="amq"/>
            <permission type="createDurableQueue" roles="amq"/>
            <permission type="deleteDurableQueue" roles="amq"/>
            <permission type="createAddress" roles="amq"/>
            <permission type="deleteAddress" roles="amq"/>
            <permission type="consume" roles="amq"/>
            <permission type="browse" roles="amq"/>
            <permission type="send" roles="amq"/>
            <!-- we need this otherwise ./artemis data imp wouldn't work -->
            <permission type="manage" roles="amq"/>
         </security-setting>
      </security-settings>

      ...

  </core>

</configuration>

默认消息地址设置

AMQ Broker 包括一个默认地址，它建立一组要应用到任何创建队列或主题的默认配置设置。

另外，默认配置定义了两个队列： DLQ (Dead Letter Queue)处理到达没有已知目的地的消息，并且 Expiry Queue 包含已持续到期的消息，因此不应路由到其原始目的地。

<configuration ...>

   <core ...>

      ...

      <address-settings>
         ...
         <!--default for catch all-->
         <address-setting match="#">
            <dead-letter-address>DLQ</dead-letter-address>
            <expiry-address>ExpiryQueue</expiry-address>
            <redelivery-delay>0</redelivery-delay>
            <!-- with -1 only the global-max-size is in use for limiting -->
            <max-size-bytes>-1</max-size-bytes>
            <message-counter-history-day-limit>10</message-counter-history-day-limit>
            <address-full-policy>PAGE</address-full-policy>
            <auto-create-queues>true</auto-create-queues>
            <auto-create-addresses>true</auto-create-addresses>
            <auto-create-jms-queues>true</auto-create-jms-queues>
            <auto-create-jms-topics>true</auto-create-jms-topics>
         </address-setting>
      </address-settings>

      <addresses>
         <address name="DLQ">
            <anycast>
               <queue name="DLQ" />
            </anycast>
         </address>
         <address name="ExpiryQueue">
            <anycast>
               <queue name="ExpiryQueue" />
            </anycast>
         </address>
      </addresses>

   </core>

</configuration>