activemq消息清理

本文讲述activemq的消息清理方法：

1. 配置法
2. 命令行

purge和delete有什么区别呢

我们看到管理界面的queue里有purge和delete，而且注意：只有queue有purge。

他们的区别很简单：

• purge: 只是清空队列里的消息，并把消息放入已经出队里
• delete: 删除这个queue，在列表里会消失

为什么要删除过期的queue或topic？

因为，如果不删除不仅占空间，而且堆积太多会导致管理界面卡顿。

通过配置定时清理

官方文档：http://activemq.apache.org/delete-inactive-destinations

配置有以下几个：

1. schedulePeriodForDestinationPurge="60000",代表每60秒清理一次,默认为0
2. gcInactiveDestinations="true"，代表回收不活跃目标，默认是false
3. inactiveTimeoutBeforeGC="30000",当目标限制30秒删除，默认60秒

    <broker xmlns="http://activemq.apache.org/schema/core" brokerName="localhost" useJmx="true" 
		dataDirectory="${activemq.data}" schedulePeriodForDestinationPurge="60000">

        <destinationPolicy>
            <policyMap>
              <policyEntries>
                <policyEntry topic=">" >
                  <pendingMessageLimitStrategy>
                    <constantPendingMessageLimitStrategy limit="1000"/>
                  </pendingMessageLimitStrategy>
                </policyEntry>
		<policyEntry queue=">" gcInactiveDestinations="true" inactiveTimeoutBeforeGC="30000"/>
              </policyEntries>
            </policyMap>
        </destinationPolicy>

结果示例：

2020-04-07 16:09:16,619 | INFO  | 0c2f8e32-3a4b-449a-807f-086012425188 Inactive for longer than 30000 ms - removing ... | org.apache.activemq.broker.region.Queue | ActiveMQ Broker[localhost] Scheduler
2020-04-07 16:09:16,620 | INFO  | b3004cb2-d625-44e3-b18a-33e857a6b69d Inactive for longer than 30000 ms - removing ... | org.apache.activemq.broker.region.Queue | ActiveMQ Broker[localhost] Scheduler
2020-04-07 16:09:16,621 | INFO  | 32d7e194-15ba-458b-a4f9-91a41d37fb32 Inactive for longer than 30000 ms - removing ... | org.apache.activemq.broker.region.Queue | ActiveMQ Broker[localhost] Scheduler
2020-04-07 16:09:16,622 | INFO  | 8ffa6724-0ec9-4128-93bb-0955e0066a8c Inactive for longer than 30000 ms - removing ... | org.apache.activemq.broker.region.Queue | ActiveMQ Broker[localhost] Scheduler

命令行清理

purge是清理，比如清理一个queue的所有或部分消息

# bin/activemq purge 00015a7f-5bc4-4a76-aab3-366dee279320

...
INFO: Purging all messages in queue: 00015a7f-5bc4-4a76-aab3-366dee279320

正则匹配删除：可以选择性地清理某些queue/topic里满足条件地message：

Examples:
    Main purge FOO.BAR
        - Delete all the messages in queue FOO.BAR
    Main purge --msgsel "JMSMessageID='*:10',JMSPriority>5" FOO.*
        - Delete all the messages in the destinations that matches FOO.* and has a JMSMessageID in
          the header field that matches the wildcard *:10, and has a JMSPriority field > 5 in the
          queue FOO.BAR.
          SLQ92 syntax is also supported.
        * To use wildcard queries, the field must be a string and the query enclosed in ''
          Use double quotes "" around the entire message selector string.

比如：清理000开始的queue的消息

# bin/activemq purge 000*

命令行我没找到删除功能,通过上面的配置可以定时移除。