I am using message groups with ActiveMQ 5.4.1 and when ending the group I'm seeing some odd behavior.
I run two consumers on Queue A. There is a 200ms delay when processing a message. I have a producer send 500 messages with group A to the broker with the last having a group sequence of -1. The first consumer starts processing messages from group A while the producer is creating the messages, but as soon as the broker gets the message with group sequence of -1 that message gets sent to the second consumer, and then the remaining in the group go to the second consumer. So the processing is out of order and all the messages don't go to the same consumer.
I believe only messages created after the one with group sequence of -1 should go to the second consumer. And the message with -1 sequence gets processed last. Should this also be the case if the master broker fails over during this time?
AMQ-2952 does not appear to be the same issue. Unfortunately I do not have time to test this against the current snapshot or include a test case. The scenario, however, is very simple and I'm sure it would be easy to whip up an example.