I would fiddle with the prefetch limits to begin with. To see if it makes a difference, you can increase the queue prefetch limit for your consumers as much as you can (subject to heapspace constraints on the consumers).
Estimate the extra heapspace needed to hold the prefetched messages in the consumer by prefetch_limit x message_size = extra and make sure you have plenty. http://activemq.apache.org/what-is-the-prefetch-limit-for.html You say the performance-per-consumer drops significantly as you add consumers... Just to be sure: are your consumers sharing no resources (apart from the broker on a different box?) Are your messages reasonably small and your network pipes sufficiently large? As well as info on the prefetch limit, there is more tuning information in ActiveMQ in Action, section 13.3 "Optimizing message consumers" In particular, you should look at DUPS_OK_ACKNOWLEDGE instead of the auto ack that you are using. ----- Michael Hayes B.Sc. (NUI), M.Sc. (DCU), SCSA SCNA -- View this message in context: http://activemq.2283324.n4.nabble.com/Consumer-performance-tp4653260p4653278.html Sent from the ActiveMQ - User mailing list archive at Nabble.com.
