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| <document> |
| |
| <properties> |
| <title>Apache James Server 3 - ActiveMQ Configuration</title> |
| </properties> |
| |
| <body> |
| <section name="ActiveMQ Configuration"> |
| |
| <p>Consult <a href="https://github.com/apache/james-project/blob/master/server/apps/cassandra-app/sample-configuration/activemq.properties">activemq.properties</a> in GIT to get some examples and hints.</p> |
| |
| <p> |
| Use this configuration to configure ActiveMQ AQMP. It is only applicable with Guice products. |
| </p> |
| |
| </section> |
| |
| |
| <section name="ActiveMQ Metrics Configuration"> |
| <p> |
| ActiveMQ offers some metrics that are available via statistics plugin |
| (see https://activemq.apache.org/statisticsplugin.html): |
| </p> |
| <ul> |
| <li> |
| Broker statistics: metrics about the broker itself such as <em>memoryUsage</em>, |
| <em>maxEnqueueTime</em>, <em>consumerCount</em> etc. Those metrics can be used for |
| monitoring and alerting (e.g. Prometheus). |
| </li> |
| <li> |
| Queue statistics: For each created queue statistics will be collected, too. Usually, |
| the queues <em>spool</em> and <em>outgoing</em> are available, but are not limited to. |
| Having multiple RemoteDelivery mailets in place, then multiple <em>outgoing-*</em> queues |
| can be available. |
| </li> |
| </ul> |
| <p> |
| Basically, the metric collector sends an AQMP message to ActiveMQ requesting the statistics |
| mentioned above. ActiveMQ responds with a message containing those statistics. |
| </p> |
| |
| <p> |
| Metrics Configuration |
| </p> |
| <dl> |
| <dt><strong>metrics.enabled</strong></dt> |
| <dd>Enable collecting metrics (default: true)</dd> |
| |
| <dt><strong>metrics.start_delay (default: 1s, minimum: 1s)</strong></dt> |
| <dd>Add a delay before starting collecting metrics on James' startup. You may increase this |
| value if the embedded ActiveMQ takes long to start.</dd> |
| |
| <dt><strong>metrics.interval (default: 5s, minimum: 5s)</strong></dt> |
| <dd>Define the interval how often the metrics should be collected.</dd> |
| |
| <dt><strong>metrics.timeout (default: 2s, minimum: 2s)</strong></dt> |
| <dd>Timeout used by the collector to wait for an ActiveMQ response to arrive. This timeout is |
| useful if the AQMP timeout (i.e. receive timeout) is not considered (see below).</dd> |
| |
| <dt><strong>metrics.aqmp_timeout (default: 1s, minimum: 1s)</strong></dt> |
| <dd>AQMP timeout (i.e. receive timeout) used by the collector when sending an AQMP message. |
| If the prefetch policy (ActiveMQ connection option) is zero, then the receive timeout is |
| indefinite. Thus, the option <em>metrics.timeout</em> helps to have an additional timeout |
| in place. |
| <br /> |
| When James is not under heavy requesting and receiving statistics takes 50-80ms (mean). |
| </dd> |
| </dl> |
| </section> |
| |
| </body> |
| </document> |
