NPE with SSO in cluster

[prabhat.jha]

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?

[brian.stansberry]

See http://fisheye.jboss.org/browse/JBossAS/branches/Branch_4_2/tomcat/src/main/org/jboss/web/tomcat/service/sso/TreeCacheSSOClusterManager.java?r1=60265&r2=72794 for the change.

The JBoss Cache getChildrenNames() will return null if there are no children; in this case meaning there are no SSOs.