Hi,
I have updated my application from ActiveMQ 5.3 to 5.11.1 and have noticed
a performance degregation issue. Running a number of jstacks I can see the
broker is often stuck here:
"Queue:master-items" Id=122 RUNNABLE
at
org.apache.activemq.broker.region.cursors.OrderedPendingList.contains(OrderedPendingList.java:144)
at
org.apache.activemq.broker.region.Queue.doPageInForDispatch(Queue.java:1930)
at org.apache.activemq.broker.region.Queue.pageInMessages(Queue.java:2119)
at org.apache.activemq.broker.region.Queue.iterate(Queue.java:1596)
- locked java.lang.Object@253c3089
at
org.apache.activemq.thread.DedicatedTaskRunner.runTask(DedicatedTaskRunner.java:112)
at
org.apache.activemq.thread.DedicatedTaskRunner$1.run(DedicatedTaskRunner.java:42)
Number of locked synchronizers = 1
- java.util.concurrent.locks.ReentrantReadWriteLock$NonfairSync@2eb46567
For this specific queue, there are a large number of items in it.. around
100,000. However I noticed the code for contains has:
public boolean contains(MessageReference message) {
if (message != null) {
for (PendingNode value : map.values()) {
if (value.getMessage().equals(message)) {
return true;
}
}
}
return false;
}
This will obviously be very slow. Given the Map is keyed by message ID,
can't we do a .contains(message.getMessageId()) instead? I noticed the
remove() method does this. I am not familiar with the internals of
ActiveMQ, so I don't know the ramifications of this.
Cheers,
David
