Cluster not load-balancing, ideas?

Question

I've been struggling to identify why my JMS producers are not load-balancing against a remote cluster.
          I've ruled out the producer as being the problem (I see the same non-load-balancing behavior regardless of what I use to create messages - Hermes, ALSB, simple Java producer...) I also don't think the JMS Connection Factory config is the problem, judging by the help I've received from folks over on the jms forum.
          I believe something is wrong with our cluster setup because in addition to the problem I just mentioned, we also are not seeing JNDI entries propagate to all managed servers - for example, if I create one jms queue on m1, that queue does not appear in the jndi tree on m2.
          I've been trying to find any documentation on what settings I should look at to verify the cluster configuration. If I go through the WLS console and look at the Cluster settings, I see both managed servers there, is there some other place that the configuration could be messed up?
          Added 6/11, 9:30 am:
          We're focusing on multicast now as the most likely problem. Can anyone tell me whether clusters on the same multicast address but different ports will interfere with each other? It looks like the infrastructure team has set up 5 clusters like that (same multicast address in each cluster, but different ports).
          We've got a ticket open with BEA but it's been two weeks now and nothing except requests for more information.
          Any ideas/help are much appreciated!
          Meghan
          Edited by pietila at 06/11/2008 7:38 AM

Answer 1

Meghan Pietila wrote:
          > I've been struggling to identify why my JMS producers are not load-balancing against a remote cluster.
          >
          > I've ruled out the producer as being the problem (I see the same non-load-balancing behavior regardless of what I use to create messages - Hermes, ALSB, simple Java producer...) I also don't think the JMS Connection Factory config is the problem, judging by the help I've received from folks over on the jms forum.
          >
          > I believe something is wrong with our cluster setup because in addition to the problem I just mentioned, we also are not seeing JNDI entries propagate to all managed servers - for example, if I create one jms queue on m1, that queue does not appear in the jndi tree on m2.
          >
          > I've been trying to find any documentation on what settings I should look at to verify the cluster configuration. If I go through the WLS console and look at the Cluster settings, I see both managed servers there, is there some other place that the configuration could be messed up?
          >
          > Added 6/11, 9:30 am:
          > We're focusing on multicast now as the most likely problem. Can anyone tell me whether clusters on the same multicast address but different ports will interfere with each other? It looks like the infrastructure team has set up 5 clusters like that (same multicast address in each cluster, but different ports).
          >
          > We've got a ticket open with BEA but it's been two weeks now and nothing except requests for more information.
          >
          > Any ideas/help are much appreciated!
          >
          > Meghan
          >
          > --
          > Edited by pietila at 06/11/2008 7:38 AM
          You could be right. I think we have had problems where the same IP but
          different ports were used for multicast. This is on 8.1 though.
          I think as a rule, it's best to have a different ip and port for each
          cluster.
          Also - can you be sure that no one else is using the multicast addresses
          on the network for anything else - we had someone bring up a test
          cluster using our addresses which caused a few issues and took a while
          to find! We also have security cameras which also use multicast, which
          if they are using the same address/port can cause issues!
          We're using 239.192.1.4:8001 for one cluster and 239.192.1.3:7001 for
          the other - I think it's best to keep those as different as you can.
          In 8.1, there is also the multicast monitor utility - there's a support
          pattern on e-support on how to diagnose it. I've found this useful in
          the past when I've suspected a cluster issue.
          https://support.bea.com/application_content/product_portlets/support_patterns/wls/MulticastErrorsPattern.html
          Check also that you're using a valid range for the address - we weren't
          for a while and had odd problems from time to time.
          There are also cluster debug flags available which you'll see listed in
          the support document.
          Are you seeing dropped multicast packets?
          Hope that helps.
          Pete