Hi, We need to implement a parallelising system using messaging - work is handled by message beans. The upstream and message processing works fine - we've run cluster performance tests on 200000 messages and scalability is fine (and linear across 3 systems in a cluster). The problem is to determine the best way of knowing when all the messages have been processed. Initial attempts resulted in the thread http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4138673#... which wasn't much use. I am loathe to use a semaphore approach - we know the number of messages before we start, so each message could decrement this - as this would introduce contention on the semaphore (however implemented I think). There doesn't appear to be a way of querying the queue. We can't stick a 'final' message onto the queue as this could be processed before all the others have been processed (each message can take a while). I have some other ideas, but they're all a bit twiddly : entry in DB for each completion ... count entries) Just wondering if anyone has had the same problem - and what suggestions there are for solving it? Many Thanks tim View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4138731#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...