Finally I thought it worthwhile posting a view of what happened around the time of the "hang" from the STD Out logs of one of the unaffected kernels... 1 kernel leaves and rejoins then around 2 minutes later the problem kernel leaves the cluster. 11:23:45,111 INFO [DefaultPartition] Suspected member: cathlbgts06:39562 (additional data: 16 bytes) 11:23:45,111 INFO [DefaultPartition] New cluster view for partition DefaultPartition (id: 19, delta: -1) : [10.9.181.48:1104, 10.9.181.51:1104, 10.9.118.3:1104, 10.9.118.2:1104] 11:23:45,112 INFO [DefaultPartition] I am (10.9.181.48:1104) received membershipChanged event: 11:23:45,112 INFO [DefaultPartition] Dead members: 1 ([10.9.181.50:1104]) 11:23:45,112 INFO [DefaultPartition] New Members : 0 ([]) 11:23:45,112 INFO [DefaultPartition] All Members : 4 ([10.9.181.48:1104, 10.9.181.51:1104, 10.9.118.3:1104, 10.9.118.2:1104]) 11:23:46,394 INFO [DefaultPartition] New cluster view for partition DefaultPartition (id: 20, delta: 1) : [10.9.181.48:1104, 10.9.181.51:1104, 10.9.118.3:1104, 10.9.118.2:1104, 10.9.181.50:1104] 11:23:46,394 INFO [DefaultPartition] I am (10.9.181.48:1104) received membershipChanged event: 11:23:46,394 INFO [DefaultPartition] Dead members: 0 ([]) 11:23:46,395 INFO [DefaultPartition] New Members : 1 ([10.9.181.50:1104]) 11:23:46,395 INFO [DefaultPartition] All Members : 5 ([10.9.181.48:1104, 10.9.181.51:1104, 10.9.118.3:1104, 10.9.118.2:1104, 10.9.181.50:1104]) 26651.767: [Rescan (parallel) , 0.0052600 secs]26726.655: [Rescan (parallel) , 0.0429900 secs]11:25:42,333 INFO [DefaultPartition] Suspected member: cathlbgts01:35704 (additional data: 15 bytes) 11:25:42,335 INFO [DefaultPartition] New cluster view for partition DefaultPartition (id: 21, delta: -1) : [10.9.181.48:1104, 10.9.181.51:1104, 10.9.118.3:1104, 10.9.181.50:1104] 11:25:42,335 INFO [DefaultPartition] I am (10.9.181.48:1104) received membershipChanged event: 11:25:42,335 INFO [DefaultPartition] Dead members: 1 ([10.9.118.2:1104]) 11:25:42,335 INFO [DefaultPartition] New Members : 0 ([]) 11:25:42,335 INFO [DefaultPartition] All Members : 4 ([10.9.181.48:1104, 10.9.181.51:1104, 10.9.118.3:1104, 10.9.181.50:1104]) Thanks in advance for any assistance. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4130848#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...