3 Replies Latest reply on Oct 12, 2010 10:44 AM by java_mojito

    EJB 3.1 Singleton and Cluster

    jojopotatoe

      I have a question about the future implementation of Singleton Bean.

       

      Do you plan to apply HA fonctionnality to @Singleton bean, i mean ability to restart the singleton bean on others server instance on a failure ?

       

      I am very happy to see part of the EJB 3.1 in the current version, many thanks.

        • 1. Re: EJB 3.1 Singleton and Cluster
          jaikiran

          Sorry, forgot to reply to this earlier.

           

          Jojopotatoe wrote:

           

           

           

          Do you plan to apply HA fonctionnality to @Singleton bean, i mean ability to restart the singleton bean on others server instance on a failure ?

           

           

          Right now, the main priority is to get the EJB3.1 spec compliant singleton implementation available ASAP. Although, i haven't looked into the details about HA functionality  for Singleton, i guess we could do/use the same infrastructure as what we have for providing HA for @Stateful beans. So yes, i think this should be possible. More on this, once we have the @Singleton implementation out. So stay tuned!

          Jojopotatoe wrote:

           

          I am very happy to see part of the EJB 3.1 in the current version, many thanks.

          Good to know

          • 2. Re: EJB 3.1 Singleton and Cluster
            jojopotatoe

            A little up .

             

            Is it possible to declare @Singleton bean as HA artefact ? Is there some guides or articles that we can use in order to try it ?

             

            Regards.

            • 3. Re: EJB 3.1 Singleton and Cluster
              java_mojito

              hello,

              i'm a newby in the EJB world. i'm testing the singleton bean using jboss AS 6.0.0.M4

              i already tested functionalities specified in the spec but some issues are not specified and i didn't find the answer in discussions.

              it's related to the behaviour of singletons in a clustered environment. i knew that an application singleton instance will be provided per JVM.

              does @singleton guarantee propagating changes made on one instance to others? i would be greatful if you  tell what mecanisms jboss uses to deal with that.

              Thank u