well, we've just got bit by something huge.
Previously we have been shipping messages from producer to consumer via a named Queue 'Index2.EntityIncrementalIndexer', where the machine index2 has a consumer called "EntityIncrementalIndexer" using persisted messages.
The design used Composite destinations so that the destination could be:
and have the 2 hosts get sent the same message simply, and if one goes down, it'll catch up later. This gave us the ability to have a mirrored configuration, and go tertiary later if we want simply by adding a new name in the composite destation.
With a single name, this works great, been working fine for months. Yesterday we activated the true composite destination, and both machines started getting their messages fine.
no problems so far, BUT, 12 hours later we have noticed that the broker has now stopped accepting messages, and a look at the activemq_msgs table shows 33228 messages