Hi, We experienced a server hang a couple of days back and analyzed the thread dump. We use JBoss 4.2 GA, JBM 1.4. The sever seems to hang due to the 2 threads below. The Thread: Thread-136 : has the WriterpreferenceLock and the MessageSucker Lock and is waiting for the lock to be released on java.lang.Object@1b6b0a1. While the Thread Thread-50 has the lock on java.lang.Object@1b6b0a1 and is waiting for MessageSucker leading to the Dead Lock Situation. Could publish the full dump after I confirm that I have the necessary permissions. Any hint on how to avoid this would really be appreciated. Ranga | Thread: Thread-136 : priority:5, demon:true, threadId:44755, threadState:BLOCKED, lockName:java.lang.Object@1b6b0a1 | org.jboss.messaging.core.impl.MessagingQueue.unregisterSucker(MessagingQueue.java:386) | --------------------------------------------------------------------------------- | The previous method call is waiting for Lock java.lang.Object@1b6b0a1 | --------------------------------------------------------------------------------- | org.jboss.messaging.core.impl.clusterconnection.MessageSucker.stop(MessageSucker.java:178) | --------------------------------------------------------------------------------- | The previous method call seems to have the the Lock on Message Sucker. | --------------------------------------------------------------------------------- | org.jboss.messaging.core.impl.clusterconnection.ClusterConnectionManager.removeSucker(ClusterConnectionManager.java:508) | org.jboss.messaging.core.impl.clusterconnection.ClusterConnectionManager.notify(ClusterConnectionManager.java:384) | org.jboss.messaging.core.impl.DefaultClusterNotifier.sendNotification(DefaultClusterNotifier.java:72) | org.jboss.messaging.core.impl.postoffice.MessagingPostOffice.removeBindingInMemory(MessagingPostOffice.java:2339) | --------------------------------------------------------------------------------- | The previous method call seems to have the the Writer Preference Lock | --------------------------------------------------------------------------------- | org.jboss.messaging.core.impl.postoffice.MessagingPostOffice.cleanDataForNode(MessagingPostOffice.java:2690) | org.jboss.messaging.core.impl.postoffice.MessagingPostOffice.nodesLeft(MessagingPostOffice.java:963) | org.jboss.messaging.core.impl.postoffice.GroupMember$ControlMembershipListener$1ViewChangeRunnable.run(GroupMember.java:517) | java.lang.Thread.run(Thread.java:595) | | | Thread: Thread-50 : priority:5, demon:false, threadId:220, threadState:BLOCKED, | lockName:org.jboss.messaging.core.impl.clusterconnection.MessageSucker@eb9dfa | org.jboss.messaging.core.impl.clusterconnection.MessageSucker.setConsuming(MessageSucker.java:208) | --------------------------------------------------------------------------------- | The previous method call is waiting for Lock org.jboss.messaging.core.impl.clusterconnection.MessageSucker@eb9dfa | --------------------------------------------------------------------------------- | org.jboss.messaging.core.impl.MessagingQueue.informSuckers(MessagingQueue.java:565) | org.jboss.messaging.core.impl.MessagingQueue.deliverInternal(MessagingQueue.java:515) | org.jboss.messaging.core.impl.ChannelSupport.deliver(ChannelSupport.java:226) | ----------------------------------------- | The previous method call seems to have the the lock on java.lang.Object@1b6b0a1" | ----------------------------------------- | org.jboss.jms.server.endpoint.ServerSessionEndpoint$2.run(ServerSessionEndpoint.java:1598) | EDU.oswego.cs.dl.util.concurrent.QueuedExecutor$RunLoop.run(QueuedExecutor.java:89) | java.lang.Thread.run(Thread.java:595) | | View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4217284#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...