2 Replies Latest reply on Feb 7, 2003 10:13 AM by Tomas Kysela

    questions about local interfaces and clustering

    Tomas Kysela Newbie

      Hallo to everybody

      I have seen several postings on this forum related to this topic and maybe I am missing something, but I am completely lost.

      I am designing an J2EE application and I know that it will from the beginning run in clustered environment. Is it possible to use local interfaces for entity beans here?

      If yes: are there any limits for clustering local entity beans? What about load balancing and fail-over with local interfaces? What about CMR in clustered environment?

      If no: why?

      My company is going to buy JBoss Clustering documentation, but till that time, answers to theese questions (or just simple guideline or point to an article) will really help me a lot.

      Thank you in advance

      Tomas Kysela
      PosAm Bratislava
      Slovak Republic

        • 1. Re: questions about local interfaces and clustering
          Sacha Labourey Master

          hello Tomas,

          Most of the time, you will only cluster what external clients use from your applications. Consequently, most of the time you will only cluster the facade SLSB and not the EB. Then, you deploy your *complete* application on *all* nodes. What is absolutly to avoid is to have some calls using some EB running on one node and then failing over to another node: performance is crap, adminstration is a nightmare, plus you would have to use distributed transaction (and it is not even sure it would work as XA drivers have limitations in this area)

          Keep it simple: cluster only what you need. Here I made the hypothesis that you have swing clients. If you have servlet clients, then that is even easier: simply cluster your HTTP session and make all your servlets only access the local EJBs (no remote calls to the other nodes, stay local)

          Cheers,


          sacha

          • 2. Re: questions about local interfaces and clustering
            Tomas Kysela Newbie

            Thank you Sacha, at least one clear answer about where the J2EE is now (I do not want to complain, I just like when things are clear and not misty (like chapters dedicated to clustering in Mastering EJB2 and Professional EJB)).
            Thank you also for really quick response. Have a safe and productive rest of the day :-)

            Tomas