title: Java Hazelcast Tomcat Web Clustering
body: <p>I am trying to implement a sticky session based load balancing across two Tomcat instances using the Hazelcast Tomcat Web Session Replication. For testing purposes, I have deployed the application on two different Tomcat instances and the load balancing is handled through Apache HTTPD. The jvmroute parameters and the mod-proxy settings are fine and the load balancing has no issues. </p>
  
  <p>The problem is with the session replication across the two instances. When the first server (currently serving the request) goes down the request is sent to the second server. The Hazelcast cluster identifies that the session is through fail-over and is copying the session with the new session id (suffixed with the jvmroute parameter of the second server) - as described in the Hazelcast documentation <a href="https://github.com/hazelcast/hazelcast-tomcat-sessionmanager#sticky-sessions-and-tomcat" rel="nofollow">https://github.com/hazelcast/hazelcast-tomcat-sessionmanager#sticky-sessions-and-tomcat</a>) . However for the failed-over request, the session attributes are getting updated in the older session(failed over jvmroute)  and not getting replicated resulting in the failure of the subsequent request. </p>
  
  <p>I have gone through the documentation but unable to find a resolution at this point. I am sure I am missing some setting as this would be a basic setting for a fail over scenario. </p>
  
  <p>Can someone help me out? Please let me know if you need any additional details.</p>
  
  <p>[UPDATE]
  After tracing the flow, able to determine that the handleTomcatSessionChange in com.hazelcast.session.HazelcastSessionChangeValve is being called correctly. The request.changeSessionId(newSessionId) call happens and post this if I display the value of the requestedsession id, the value is updated. However, the session id by itself is not updated and this is resulting in the older id in a request.getSession().getId() call.  </p>