0 Replies Latest reply on Jul 29, 2004 3:52 PM by James Adams

    Singletons with Clustering

    James Adams Novice

      Am I the only one using singletons with clustering ? It seems to be something which should have been done many times before, but detailed information on how it works does not seem to be readily available. I have posted two messages to the JBoss/Clustering forum (see http://www.jboss.org/index.html?module=bb&op=viewtopic&t=52358 and http://www.jboss.org/index.html?module=bb&op=viewtopic&t=52330) but I have yet to receive any more information on how to get this to work. Does anyone have any experience with this ?

      This is my first attempt to use JBoss Clustering, and aside from the singletons it appears to be simple to setup and run a JBoss cluster. The only article on how this works for singletons, http://www.onjava.com/pub/a/onjava/2003/08/20/jboss_clustering.html, which outlines creating a MBean to run as a singleton using the HASingletonController, isn't complete (no code for the MBean interface, no real direction on which cluster-service.xml to include the singleton and controller entries -- is it cluster-service.xml or cluster-examples-service.xml ?, do you package the SingletonMBean with other Mbeans in a SAR or in the EAR file ?, etc.), and I am having troubles not mentioned in the article.

      The JBoss Clustering documentation I have shows that there are no clustering features available for Message-Drive EJBs -- so does this mean that running a singleton MDB, which runs fine in single JVM, as a singleton in the cluster is impossible ? If not then what else is required other than marking the MDB as in the joss.xml ?

      I am running JBoss 3.2.5. Any suggestions or information would be appreciated. Thanks in advance.