1 Reply Latest reply on Apr 22, 2005 12:02 PM by Ben Wang

    2 Masters in a Singleton service!

    Siddhartha Azad Newbie

      Hi, I am able to consistently replicate a case where I get 2 Masters elected in a Singleton service deployed on 2 hosts on the same cluster. This is what I did:
      (Using JBoss 3.2.3.)
      (1. Started JBOss and the singleton service on a host, say Host A. This becomes the Master.
      (2. Started JBoss and the singleton service on another host, say Host B.
      (3. Host A is the Master at this point.
      (4. I remove the LAN cable and disconnect host A from the network.
      (5. Now Host B becomes the Master and host A remains to be the Master. Of course they are not on the same cluster any more since there is no conenctivity from host B to host A.
      (6. Now I reconnect the LAN cable to host A to restore connectivity. Host B receives a cluster membership changed event and shows host A as 1 of the members in the cluster.
      (7. Host A also shows host B in its list of cluster members, BUT remains to be the Master!
      Hence we have 2 masters at this point, both Host A and host B, that are on the same cluster.
      I was able to see this problem in JBoss 3.2.3. This problem DOES NOT happen in JBoss 4.0.1 sp1.
      Please advise,
      Thanks, Sid.