I have an mdb configured with max sessions = 15. I will load the queue up with 3000 messages and it looks like 15 messages will get consumed and as they are consumed new messages are grabbed from the queue. So that is fine, but what I see is that on a regular basis several messages will finish their processing the InProcessMessageCount will drop significantly below 16 and it will take a couple of seconds processing only a few messages at a time and then it will jump back up to the 15 it should be processing at a time. Why doesn't the number of messages stay at around 15 why does it dip so much? I am running Jboss-4.2.3.GA. Any ideas on how to keep the messages being consumed up at 15?