4 Replies Latest reply on May 10, 2013 5:28 AM by Radoslav Husar

    Clustering question with multislot in standalone mode

    Markus Falk Newbie

      Hello together.

       

      I have a clustering question when running two slots on two nodes setup of JBoss 7.2, running in standalone mode. The setup looks like this:

       

      node1 slot1 and node2 slot1 -> should form a cluster

      node1 slot2 and node2 slot2 -> should form a cluster

       

      But when I deploy a war with the <distributable/> element in the web.xml all the nodes try to form a cluster. When I set the node ids of the servers to different names, they actually form a cluster without exceptions.

       

      When I make a netstat to the jgroup-udp ports I see that slot1 and slot2 are listening on the same ports. Example from node1:

       

      falk@markusfalk:~$ netstat -a

      udp        0      0 239.252.1.81:45688      *:*                               

      udp        0      0 239.252.1.81:45688      *:*

       

      I also noticed, when the multicast-ports per slot differ, the clusters behaves like they should.

       

      So my questions:

      - Are the multicast-ports not touched by the port-offest setting?

      - Is the jgroups wrong configured when they form a cluster here? or

      - Is it in my responsibility to set the multicast-ports different on each slot?

       

       

      Thank you in advance for your response :-)

       

      Best regards,

      Markus

        • 1. Re: Clustering question with multislot in standalone mode
          Radoslav Husar Master

          - Are the multicast-ports not touched by the port-offest setting?

          No, they are not touched.

          - Is the jgroups wrong configured when they form a cluster here? or

          No, its correct.

          - Is it in my responsibility to set the multicast-ports different on each slot?

          Yes, it is.

           

          You can also just change the multicast group. I actually recommend this way, as it is easier to route this traffic as opposed to the port. Performance like, this should be no different as the UDP layer uses both the destination address and port to un-multiplex the packets.

          • 2. Re: Clustering question with multislot in standalone mode
            Radoslav Husar Master

            Regarding:

             

            When I set the node ids of the servers to different names, they actually form a cluster without exceptions.

             

            The name is uniquely generated per machine, so if you are running 2 jboss instances, you need to specify different node names for each (so manually assign node name at least for one).

            • 3. Re: Clustering question with multislot in standalone mode
              Markus Falk Newbie

              Hi Radoslav,

               

              thank you for your answer!

               

              I adjusted the multicast-ports and it works perfect :-)

               

              Regarding your answers:

              - I suppose with the multicast group you mean the multicast-address. Correct? I found nothing in the XML schema that indicates an attribute called multicast-group or a startup parameter that could be set by JAVA OPTS.

              - When I distinguish the multicast-ports then it should do no harm when the different slots have the same node-id because they don't 'see' each other. Correct, too? ;-)

               

              Thx again and have a nice weekend!

               

               

              Regards,

              Markus

              • 4. Re: Clustering question with multislot in standalone mode
                Radoslav Husar Master

                I am glad to hear it worked!

                 

                - I suppose with the multicast group you mean the multicast-address. Correct? I found nothing in the XML schema that indicates an attribute called multicast-group or a startup parameter that could be set by JAVA OPTS.

                Yes, that's right. Actually the clearest term would be "multicast group address". In socket-binding-group you need to find the mping multicast-address, or you can just set it via -Djboss.default.multicast.address=230.0.0.4

                 

                - When I distinguish the multicast-ports then it should do no harm when the different slots have the same node-id because they don't 'see' each other. Correct, too? ;-)

                Oh yes that's right, but it would be a good practice to differentiate them anyway, in case you want to make them all form a cluster on day to, for instance, provide a HA singleton (not necessarily cluster the sessions).