<div class="docbook"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Appendix E. Queue Alerts</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="apds03.html">Prev</a> </td><th width="60%" align="center"> </th><td width="20%" align="right"> <a accesskey="n" href="Java-Broker-Miscellaneous.html">Next</a></td></tr></table><hr /></div><div class="appendix"><div class="titlepage"><div><div><h1 class="title"><a id="Java-Broker-Appendix-Queue-Alerts"></a>Appendix E. Queue Alerts</h1></div></div></div><p>The Broker supports a variety of queue alerting thresholds. Once configured on a queue,
    these limits will be periodically written to the log if these limits are breached, until the
    condition is rectified.</p><p>For example, if queue <code class="literal">myqueue</code> is configured with a message count alert of
    1000, and then owing to a failure of a downstream system messages begin to accumulate on the
    queue, the following alerts will be written periodically to the log. </p><pre class="screen">INFO [default:VirtualHostHouseKeepingTask] (queue.NotificationCheck) - MESSAGE_COUNT_ALERT On Queue myqueue - 1272: Maximum count on queue threshold (1000) breached.
  </pre><p>Note that queue alerts are <span class="emphasis"><em>soft</em></span> in nature; breaching the limit will
    merely cause the alerts to be generated but messages will still be accepted to the queue.</p><div class="table"><a id="Java-Broker-Appendix-Queue-Alerts-Alerting-Messages"></a><p class="title"><strong>Table E.1. Queue Alerts</strong></p><div class="table-contents"><table summary="Queue Alerts" width="100%" border="1"><colgroup><col class="alertname" /><col class="purpose" /></colgroup><thead><tr><th>Alert Name</th><th>Alert Format and Purpose</th></tr></thead><tbody><tr><td rowspan="2">MESSAGE_COUNT_ALERT</td><td> MESSAGE_COUNT_ALERT On Queue <em class="replaceable"><code>queuename</code></em> -
              <em class="replaceable"><code>number of messages</code></em>: Maximum count on queue threshold
              (<em class="replaceable"><code>limit</code></em>) breached. </td></tr><tr><td>
            <p>The number of messages on the given queue has breached its configured
              limit.</p>
          </td></tr><tr><td rowspan="2">MESSAGE_SIZE_ALERT</td><td> MESSAGE_SIZE_ALERT On Queue <em class="replaceable"><code>queuename</code></em>
              -<em class="replaceable"><code>message size</code></em> : Maximum message size threshold
              (<em class="replaceable"><code>limit</code></em>) breached. [Message ID=<em class="replaceable"><code>message
              id</code></em>]</td></tr><tr><td>
            <p>The size of an individual messages has breached its configured limit.</p>
          </td></tr><tr><td rowspan="2">QUEUE_DEPTH_ALERT</td><td> QUEUE_DEPTH_ALERT On Queue <em class="replaceable"><code>queuename</code></em> -
              <em class="replaceable"><code>total size of all messages on queue</code></em> : Maximum queue depth
            threshold (<em class="replaceable"><code>limit</code></em>) breached.</td></tr><tr><td>
            <p>The total size of all messages on the queue has breached its configured
              limit.</p>
          </td></tr><tr><td rowspan="2">MESSAGE_AGE_ALERT</td><td>MESSAGE_AGE_ALERT On Queue <em class="replaceable"><code>queuename</code></em> - <em class="replaceable"><code>age
              of message</code></em> : Maximum age on queue threshold
              (<em class="replaceable"><code>limit</code></em>) breached. </td></tr><tr><td>
            <p>The age of a message on the given queue has breached its configured limit.</p>
          </td></tr></tbody></table></div></div><br class="table-break" /></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="apds03.html">Prev</a> </td><td width="20%" align="center"> </td><td width="40%" align="right"> <a accesskey="n" href="Java-Broker-Miscellaneous.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">D.3. Examples </td><td width="20%" align="center"><a accesskey="h" href="Apache-Qpid-Broker-J-Book.html">Home</a></td><td width="40%" align="right" valign="top"> Appendix F. Miscellaneous</td></tr></table></div></div>