| <div class="wiki-content maincontent"><h3>Background</h3> |
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| <p>As well as having a pluggable dispatch policy (e.g. round robin etc), we now support consumer priorities.</p> |
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| <p>This allows us to weight consumers to optimise network hops. For example, you typically want a broker to send messages to regular NMS consumers rather than to other brokers; there's no need to make unnecessary broker-to-broker hops if there are available consumers.</p> |
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| <h3>Example</h3> |
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| <p>The priority for a consumer is set using <link><page ri:content-title="ActiveMQ URI Configuration"></page><link-body>Destination Options</link-body></link> as follows:</p> |
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| <structured-macro ac:macro-id="91f62f32-07fc-46ae-b30f-86646d2f98e6" ac:name="code" ac:schema-version="1"><parameter ac:name="">java</parameter><plain-text-body> |
| var queue = session.GetQueue("TEST.QUEUE?consumer.priority=10"); |
| var consumer = session.CreateConsumer(queue); |
| </plain-text-body></structured-macro> |
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| <p>The range for assigning priority numbers is from 0 to 127, with 127 being the highest priority and 0 being the default priority.<br clear="none"> |
| The way it works is that the broker will simply order any queue consumers according to their priorities and send messages to the highest priority consumers first. <br clear="none"> |
| Once a particular consumer has its prefetch buffer filled up, the broker will begin to dispatch messages to consumers of lower priorities. </p></div> |
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