I have a 2-node cluster with EAP 4.3 CP04 running portal with apache mod_jk in front. I have turned on org.jboss.web.tomcat.service.sso.ClusteredSingleSignOn in jboss-web.deployer. When failover happens, I see following in server log: 4:59:18,550 ERROR [TreeCacheSSOClusterManager] Caught exception cleaning sessions from dead cluster members from SSOs | java.lang.NullPointerException | at org.jboss.web.tomcat.service.sso.TreeCacheSSOClusterManager$DeadMemberCleaner.run(TreeCacheSSOClusterManager.java:1493) | at org.jboss.util.threadpool.RunnableTaskWrapper.run(RunnableTaskWrapper.java:148) | at EDU.oswego.cs.dl.util.concurrent.PooledExecutor$Worker.run(PooledExecutor.java:756) | at java.lang.Thread.run(Thread.java:595) | Thanks for creating https://jira.jboss.org/jira/browse/JBPAPP-1865. What could be the cause? View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4223816#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...