I'm seeing an issue where SEQUENCER is dropping messages, with logs like this:

2012-04-13 10:05:21.363 [Incoming-1,pisces,CFS-B-pisces-cfs02] ERROR org.jgroups.protocols.SEQUENCER - CFS-B-pisces-cfs02: non-coord; dropping FORWARD request from CFS-A-pisces-cfs03

It looks as though there's some sort of race where:

• a member ("CFS-B-pisces-cfs02") is becoming coordinator, but SEQUENCER hasn't yet seen the view change
• meanwhile some other member ("CFS-A-pisces-cfs03") has been told of the view change, and so SEQUENCER there forwards messages to the new coordinator
• but because the new coordinator doesn't yet know that it is coordinator, we hit the problem above.

The messages don't ever get retransmitted; so they're simply lost.

Here's some trace from the member who drops the message, with the line from my application showing that he does indeed become coordinator a few milliseconds later:

2012-04-13 10:05:21.363 [Incoming-1,pisces,CFS-B-pisces-cfs02] ERROR org.jgroups.protocols.SEQUENCER - CFS-B-pisces-cfs02: non-coord; dropping FORWARD request from CFS-A-pisces-cfs03
2012-04-13 10:05:21.393 [Incoming-2,pisces,CFS-B-pisces-cfs02] INFO c.m.c.CommunicatorComponent$Communicator - New view: MergeView::[CFS-B-pisces-cfs02|86] [CFS-B-pisces-cfs02, CFS-B-pisces-cfs03, CFS-A-pisces-cfs03, CFS-A-pisces-cfs02], subgroups=[CFS-A-pisces-cfs03|84] [CFS-A-pisces-cfs03, CFS-A-pisces-cfs02], [CFS-B-pisces-cfs03|85] [CFS-B-pisces-cfs03, CFS-A-pisces-cfs02, CFS-B-pisces-cfs02]

And here's trace from the other end, showing that message being broadcast in the new view.

2012-04-13 10:05:21.359 [Incoming-1,pisces,CFS-A-pisces-cfs03] INFO c.m.c.CommunicatorComponent$Communicator - New view: MergeView::[CFS-B-pisces-cfs02|86] [CFS-B-pisces-cfs02, CFS-B-pisces-cfs03, CFS-A-pisces-cfs03, CFS-A-pisces-cfs02], subgroups=[CFS-A-pisces-cfs03|84] [CFS-A-pisces-cfs03, CFS-A-pisces-cfs02], [CFS-B-pisces-cfs03|85] [CFS-B-pisces-cfs03, CFS-A-pisces-cfs02, CFS-B-pisces-cfs02]
2012-04-13 10:05:21.361 [ForkJoinPool-1-worker-0] INFO c.m.c.CommunicatorComponent$Communicator - Broadcasting ClusterMgmtMsg

I can try to get lower level trace from JGroups if that would help.

I'm using the same stack as in JGRP-1443.