Re: User Session using ServletSession and Stateful EJB in Cluster

Question

          Sorry , I didn't use WLS 6.0, we use wls 5.1 in production.
          But in Wls 6.0, in some situations , the state of the stateful session bean can be lost. So it's not so reliable. You have to deal with it in the client code. Instead, servlet is a reliable solution.
          In order to test under wls6.0, you can store the handle of the EJBObject in the HttpSession, not in jndi, cos if the instance fails, all its objects will be removed by remaining instances from jndi. In another instance, you get the handle, and try to get the EJBObject.
          In wls5.1, some information like the server url must be embeded inside the handle. But in wls6.0, I don't know how they deal with it.
          I am looking forward to your results
          "Anuj Soni" <[email protected]> wrote:
          >
          >What kind of clustering problems you had with WL6.0 for Stateful session beans ? It will be helpful for me to know before hand.
          >
          >BTW, how were you able to test stateful session beans in a cluster under WL6.0 i.e. were you storing the Handle or EJBObject in HttpSession or did you store it in JNDI ?
          >
          >Thanks,
          >
          >Anuj
          >"Tao Zhang" <[email protected]> wrote:
          >>Although it's very advanced to take advantage of both http session and
          >>stateful session bean replication, but if you rely on the stateful session
          >>bean's state, you will be in trouble. Because the support of stateful
          >>session bean's replication is not perfect in wls6.0. We already chaned
          >>almost all stateful session beans into servlets or entity beans.
          >>
          >>I am not sure about the handle of the EJBObject. I think it should be able
          >>to reconstruct for us otherwise we can't use the handle any more.
          >>
          >>You can do a test. BTW, could you tell me the result?
          >>
          >>Thanks.
          >>
          >>Anuj Soni <[email protected]> wrote in message
          >>news:[email protected]...
          >>>
          >>> Hi,
          >>>
          >>> I am designing the workflow for my web application using a Stateful
          >>session bean. As Weblogic 6.0 supports clustering of stateful session bean
          >>and HttpSession(in-memory replication), I want to use the combination of
          >>both techniques to provide load-balancing and fail-over safety for user
          >>sessions and their corresponding workflows.
          >>>
          >>> The question I have is that, Is Handle obtained using
          >>EJBObject.getHandle(), fail-over safe (for a clusterable stateful bean), so
          >>that I can reconstruct the reference to EJBObject on the secondary server
          >>incase of primary server crash.
          >>>
          >>> My understanding is that I should store Handle in the HttpSession as it is
          >>Serializable not the EJBObject. The weblogic 6.0 document only talks about
          >>the replica-awareness of EJBObject.
          >>>
          >>> If my above assumption is incorrect, Can you tell me how else I can
          >>achieve my goal ?
          >>>
          >>> Thanks in advance.
          >>>
          >>> Anuj Soni
          >>
          >>
          >
          

Answer 1

Any one tested this scenario yet? i.e: storing the handle to an EJB object and then trying to re-use after the HttpSession is restored?
          Thanks.