It's the second time we encountered a very strange and annoying problem with hornetq 2.1.2.Final in our production application.
Without any reason the queue seems to be "paused" and doesn't distribute message any more. This is a screenshot of the jmx console when the queue is blocked :
It is a simple queue without filters with a MDB consuming messages. As you can see the Paused status is false and there is 15 consumers but no message is distribute. The situation stay freeze until we click on resume in the jmx-console.