A good place to start is with JCosole, to have a look at the queues and consumers to see how many messages are currently in the queues.
>The broker is configured with producerFlowControl="false", using TCP, a >pre-fetch size of 0 and I've also set sendFailIfNoSpace="true". > The sendFailIfNoSpace is disabled if producerFlowControl==false, so your producers will hang if memory for the queues are exhausted. sendFailIfNoSpace is considered a flowControl mechanism that does not block so it needs producerFlowControl to be enabled (the default) and no producer window to be set (also the default). Just a thought, but is it possible that the consumers are blocking when trying to "stick messages" back on a queue? Out of interest, why are you using prefetch==0? 2009/1/13 IBeaumont <ibeaum...@categoric.com>: > > I've got a fairly complex app, that takes msgs, processing them and sticks > them on the same or different queues. > > The queues are pre-loaded with persistent messages before the application > starts (50000). Once it starts processing things work fine for a while and > then the consumers stop receiving any messages. I have a 4 consumers for > each queue, and there are 3 different queues. > > Looking at jconsole all consumes are waiting here: > > State: WAITING on java.lang.obj...@1801d4a > Total blocked: 20 Total waited: 158 > > Stack trace: > java.lang.Object.wait(Native Method) > java.lang.Object.wait(Object.java:485) > org.apache.activemq.MessageDispatchChannel.dequeue(MessageDispatchChannel.java:75) > org.apache.activemq.ActiveMQMessageConsumer.dequeue(ActiveMQMessageConsumer.java:412) > org.apache.activemq.ActiveMQMessageConsumer.receiveNoWait(ActiveMQMessageConsumer.java:560) > com.xalert.server.queuing.SessionManager.getAlert(SessionManager.java:236) > > > If I look at the broker (and I'm not really sure what to look at here), the > thread for my queue that should be dispatching messages looks like this > Name: QueueThread:queue://csPIQ > State: WAITING on > java.util.concurrent.locks.abstractqueuedsynchronizer$conditionobj...@b0a518 > Total blocked: 2,365 Total waited: 6,717 > > Stack trace: > sun.misc.Unsafe.park(Native Method) > java.util.concurrent.locks.LockSupport.park(Unknown Source) > java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(Unknown > Source) > java.util.concurrent.LinkedBlockingQueue.take(Unknown Source) > java.util.concurrent.ThreadPoolExecutor.getTask(Unknown Source) > java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) > java.lang.Thread.run(Unknown Source) > > The broker is configured with producerFlowControl="false", using TCP, a > pre-fetch size of 0 and I've also set sendFailIfNoSpace="true". > > Any ideas on what my problem is or how/where I look in ActiveMQ to find the > cause, or if the problem is with the consumer. > > TIA > Ian > > -- > View this message in context: > http://www.nabble.com/Q-Consumers-stop-receiving-messages-tp21438163p21438163.html > Sent from the ActiveMQ - User mailing list archive at Nabble.com. > > -- http://blog.garytully.com Open Source SOA http://FUSESource.com
