Set up the cluster of the session replication and it was working fine. However showing following error in the catalina.out. Sometime occurring weird behavior.
Tomcat version: Apache Tomcat/6.0.16 (1) WARNING: IOException in replication worker, unable to drain channel. Probable cause: Keep alive socket closed[Connection reset by peer]. >> For above warning i have checked forum and as suggested we do have keepAliveCount. (2) Mar 8, 2013 4:49:34 PM org.apache.catalina.tribes.group.interceptors.TcpFailureDetector memberDisappeared INFO: Received memberDisappeared[org.apache.catalina.tribes.membership.MemberImpl[tcp://{-64, -88, 3, 12}:4000,{-64, -88, 3, 12},4000, alive=45882882,id={-70 -12 103 -20 66 -83 68 53 -74 -59 -107 0 -18 -70 33 65 }, payload={}, command={}, domain={}, ]] message. Will verify. Mar 8, 2013 4:49:34 PM org.apache.catalina.tribes.group.interceptors.TcpFailureDetector memberDisappeared INFO: Verification complete. Member still alive[org.apache.catalina.tribes.membership.MemberImpl[tcp://{-64, -88, 3, 12}:4000,{-64, -88, 3, 12},4000, alive=45882882,id={-70 -12 103 -20 66 -83 68 53 -74 -59 -107 0 -18 -70 33 65 }, payload={}, command={}, domain={}, ]] Mar 8, 2013 4:49:34 PM org.apache.catalina.tribes.tipis.AbstractReplicatedMap get Operation has timed out(60000 ms.). (3) SEVERE: Unable to replicate out data for a LazyReplicatedMap.get operation java.lang.NullPointerException at org.apache.catalina.tribes.tipis.AbstractReplicatedMap.get(AbstractReplicatedMap.java:850) at org.apache.catalina.session.ManagerBase.findSession(ManagerBase.java:862) at org.apache.catalina.connector.Request.doGetSession(Request.java:2283) at org.apache.catalina.connector.Request.getSessionInternal(Request.java:2220) at org.apache.catalina.ha.session.JvmRouteBinderValve.handlePossibleTurnover(JvmRouteBinderValve.java:22 (4) SEVERE: An exception or error occurred in the container during the request processing (5) Mar 8, 2013 11:26:32 PM org.apache.catalina.ha.session.DeltaSession writeObject SEVERE: Cannot serialize session attribute CURRENT_USER for session 61CA81CF075D08855B143814C53BF136.t7 java.io.NotSerializableException: Please let us know your views on it.