Details
Minor Description
I have multiple producers posting messages to queues and adding statistical information to a topic. I have one consumer of that topic subscribing and taking those messages and monitors for problems. The consumer is slower than publishing to the topic. I have flow control enabled and I expected that once the memory limit of the Consumers dispatch queue was reached it would throttle the publishers to the topic, but instead it seems to lock everything up.
The message producers are putting messages to each queue and the topic on separate sessions. The broker basically stops once it posts the message that it's going to throttle producers. The topic messages are messages with text attributes, they are non persistent and posted non-transactional using the AUTO_ACKNOWLEDGE mode.
All the producers and consumers use the same Connection factory with with these attributes set.
ActiveMQConnectionFactory factory = new ActiveMQConnectionFactory(brokerURI);
factory.setProducerWindowSize(1024 * 1024);
factory.getPrefetchPolicy().setTopicPrefetch(10);
My activemq config is as follows:
<broker xmlns="http://activemq.apache.org/schema/core" brokerName="localhost" dataDirectory="${activemq.base}/data" destroyApplicationContextOnStop="true">
<!--
For better performances use VM cursor and small memory limit.
For more information, see:
http://activemq.apache.org/message-cursors.html
Also, if your producer is "hanging", it's probably due to producer flow control.
For more information, see:
http://activemq.apache.org/producer-flow-control.html
-->
<destinationPolicy>
<policyMap>
<policyEntries>
<policyEntry topic=">" producerFlowControl="true" memoryLimit="15mb">
<pendingSubscriberPolicy>
<vmCursor />
</pendingSubscriberPolicy>
</policyEntry>
<policyEntry queue=">" producerFlowControl="true" memoryLimit="15mb">
<!-- Use VM cursor for better latency
For more information, see:
http://activemq.apache.org/message-cursors.html
<pendingQueuePolicy>
<vmQueueCursor/>
</pendingQueuePolicy>
-->
</policyEntry>
</policyEntries>
</policyMap>
</destinationPolicy>
<!--
The managementContext is used to configure how ActiveMQ is exposed in
JMX. By default, ActiveMQ uses the MBean server that is started by
the JVM. For more information, see:
http://activemq.apache.org/jmx.html
-->
<managementContext>
<managementContext createConnector="false"/>
</managementContext>
<!--
Configure message persistence for the broker. The default persistence
mechanism is the KahaDB store (identified by the kahaDB tag).
For more information, see:
http://activemq.apache.org/persistence.html
-->
<persistenceAdapter>
<kahaDB directory="${activemq.base}/data/kahadb" journalMaxFileLength="5 mb"/>
</persistenceAdapter>
<!--
The systemUsage controls the maximum amount of space the broker will
use before slowing down producers. For more information, see:
http://activemq.apache.org/producer-flow-control.html
-->
<systemUsage>
<systemUsage>
<memoryUsage>
<memoryUsage limit="200 mb"/>
</memoryUsage>
<storeUsage>
<storeUsage limit="50 gb"/>
</storeUsage>
<tempUsage>
<tempUsage limit="100 mb"/>
</tempUsage>
</systemUsage>
</systemUsage>
<!--
The transport connectors expose ActiveMQ over a given protocol to
clients and other brokers. For more information, see:
http://activemq.apache.org/configuring-transports.html
-->
<transportConnectors>
<transportConnector name="openwire" uri="tcp://0.0.0.0:61616"/>
</transportConnectors>
</broker>