In a point-to-point queue I want to use transacted sessions to ensure messages are processed completely before being removed from the queue. The client is to be multi threaded to process messages in parallel.
I decided each thread would need it's own Session object (for transacting) so that when the work on each message is successfully completed the session can be commited. Session objects would be pooled and retrieved when the next message is ready to be received. The documentation states that, "ActiveMQ is a high performance message bus that streams messages to consumers as fast as possible so that the consumer always has a buffer of messages, in RAM, ready to process - rather than have them explicitly pull messages from the server which adds significant latency per message". The problem is that messages will not be evenly distributed amoungst Sessions, with the likeihood that a single session will be flooded with all the messages making it impossible to distribute the work amoungst multiple threads. The logical next step would be to set the prefetch limit to one and have a pull-one-message-at-a-time dispatch policy (as described here:http://activemq.apache.org/what-is-the-prefetch-limit-for.html). Apparently, this is advised against as it's very SLOW (http://osdir.com/ml/java.activemq.user/2005-03/msg00188.html). I expect millions of messages in my queue, each one can be processed in a matter of seconds. The problem of multi threading and transacted sessions must be fairly common - can anyone suggest other options? Terry -- View this message in context: http://www.nabble.com/transacted-sessions-in-multi-threaded-client-tf4603908s2354.html#a13145807 Sent from the ActiveMQ - User mailing list archive at Nabble.com.
