We're having a strange problem in our environment when the consumer is not receiving any more messages from the queue since the broker considers the consumer queue filled to the prefetch size and messages not acked though they are/should be. They are received and handled by the consumer.
I have managed to reproduce the behaviour with slightly modified examples from the binary distro. see attachment. In short what's needed is that the consumer sends a message while the broker queue is full, usage = 100 and the prefetch is also reached. To reproduce run the examples as they are on your system to get your max queue size and check the jconsole figures. cmd> ant consumer -Dmax=100000 -DsleepTime=10 cmd> ant producer -Dmax=100000 I get QueueSize = 8042 and that is the steady state, producer sends messages as they are acked from the consumer and this can go on forever. (Modify the message size, memory size etc and you can get other figures.) Now use the attached ConsumerTool.java. The modification is that it creates a separate thread with a new jms session on which it sends a heart beat message every 2 seconds. As long as the broker queue is not filled this works fine, test this by using cmd> ant consumer -Dmax=100000 cmd> ant producer -Dmax=100000 Now make sure the broker queue gets filled by cmd> ant consumer -Dmax=100000 -DsleepTime=2 cmd> ant producer -Dmax=100000 Now everything freezes 1000 messages after the most recent heart beat sent by the consumer when the broker queue is full.. What happens? I've read the post http://www.nabble.com/Consumer-blocking-when-session-created-on-same-connection-as-blocked-producer-tf3294332s2354.html but in that scenario the answer is sent within onMessage and will of course be blocked as the already blocked producer. Here it's on a separate thread. TIA /Stefan http://www.nabble.com/file/p12812854/ConsumerTool.java ConsumerTool.java -- View this message in context: http://www.nabble.com/Producer-and-consumer-hangs-with-specific-scenario-tf4492569s2354.html#a12812854 Sent from the ActiveMQ - User mailing list archive at Nabble.com.
