Weblogic Cluster In-Memory Session Replication Problem

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EJB programming & troubleshooting: Weblogic Cluster In-Memory Session Replication Problem

  1. Weblogic Cluster In-Memory Session Replication Problem (3 messages)

    We have developed a custom tailored web application running in Bea Weblogic 8.1 sp2 under linux platform.The problem is
    some times user complain about user getting reset (Session getting lost).This happens when the load increases.But the in-memory replication is happening.We are having 2 managed servers in the cluster.
    1.All session variables have been serialized
    2.Weblogic.xml
       <param-name>PersistentStoreType</param-name>
       <param-value>replicated_if_clustered</param-value>
    3.Replica Group has been interchanged
      Managed 1 Primary (Group1)
      Managed 1 Secondary (Group2)
      Managed 2 Primary (Group2)
      Managed 2 Secondary (Group1)

    Would be oblidged if could give resolve this problem

     
    Thanks
  2. We just saw a similar problem on WL 8.1 SP3 on RHEL 3.0 (which we haven't seen on SP2 on RHEL 2.1), that the sessions were behaving strangely. This turned out to be a problem with the (virtual) multicast address. We couldn't run with the original setting after upgrading, but had to change IP address of the cluster multicast from 225.1.1.225 (which was the original setting) to 237.0.0.1. This seems to have done the trick and it's working ok now.

    Hope this helps!
  3. It's a known issue: The session attributes can be lost when the load is heavy. Your choices are to use a JDBC store instead of in-memory replication, add more hardware to keep the average load down, or use a different session management implementation (like our Coherence*Web product.)

    Peace,

    Cameron Purdy
    Tangosol, Inc.
    Coherence: Shared Memories for J2EE Clusters
  4. Hi, I am building a struts based application on Weblogic Cluster. Sometimes the data I put in session does not reflect in the session of the other server. I do not expilicitly set data in session, I just take the refernce to a session object and update it. Sometimes this updation does not reflect in the other session. I have read on bea site that Weblogic does not trigger session replication unless the setAttribute() or removeAttribute() methods are called. But if that is the case, how do the data in the session scoped form beans reflect properly in both the sessions. Please help with this.