I just experienced what might be the same problem. I started up 6 nodes and one node was using up all CPU without any real load on it. Dumping all stacks shows that all threads are parked except one which is stuck on map.get in OrderedSynchronizationHandler. "ReceivingGameEventDaemon-1" prio=1 tid=0x092d5eb0 nid=0x5660 runnable [0x85421000..0x85421f30] | at java.util.HashMap.get(HashMap.java:346) | at org.jboss.cache.interceptors.OrderedSynchronizationHandler.getInstance(OrderedSynchronizationHandler.java:50) | at org.jboss.cache.interceptors.TxInterceptor.registerHandler(TxInterceptor.java:901) | at org.jboss.cache.interceptors.TxInterceptor.registerTransaction(TxInterceptor.java:877) | at org.jboss.cache.interceptors.TxInterceptor.attachGlobalTransaction(TxInterceptor.java:342) | at org.jboss.cache.interceptors.TxInterceptor.handleNonTxMethod(TxInterceptor.java:292) | at org.jboss.cache.interceptors.TxInterceptor.invoke(TxInterceptor.java:131) | at org.jboss.cache.interceptors.Interceptor.invoke(Interceptor.java:76) | at org.jboss.cache.interceptors.CacheMgmtInterceptor.invoke(CacheMgmtInterceptor.java:81) | at org.jboss.cache.interceptors.Interceptor.invoke(Interceptor.java:76) | at org.jboss.cache.interceptors.InvocationContextInterceptor.invoke(InvocationContextInterceptor.java:62) | at org.jboss.cache.interceptors.Interceptor.invoke(Interceptor.java:76) | View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4134856#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...