Not sure if this is still an issue, I was facing the same "already connected" problem even with 4.0 and 4.0.1 and I just switched from DefaultMessageListenerContainer to SimpleMessageListenerContainer and it worked fine with no such exception.
I could get this to work by replacing the DefaultMessageListenerFactory with the SimpleMessageListenerFactory class and there were no more hung servers. Side Note: I have had six listener containers and each one listens to a different Queue. This configuration works if I assign concurrentConsumers in each of these listener containers equal to 1. ( 6 x 1 = 6. ) If I assign concurrentConsumers in each of these listener containers to 2. (6 x 2 = 12 ) When I do this two listener consumers do not receive the message, implying there is a some limit on the total number of concurrentConsumers in such a configuration. -- View this message in context: http://www.nabble.com/Client%3A-XXX-already-connected-bug-tf1522491.html#a5223575 Sent from the ActiveMQ - User forum at Nabble.com.
