EJB Deployment Question

Question

If your servlets are running in the same instance as your EJBs, do you
          need to make the EJBs clusterable (i.e. set the deployment descriptor
          properties)? We have the same EJBs deployed on each server (5.1 SP8)
          and we have been getting conflict handler errors for each EJB when we
          start the second server (shown below)
          Wed Aug 01 09:05:37 CEST 2001:<I> <ConflictHandler> ConflictStop
          com.es.messaging.ESMessageQueueManagerHome_EO:com.es.messaging.ESMessageQueueManagerBeanEOImpl
          (from
          [email protected]:[7001,7001,7002,7002,7001,-1])
          Support tells us that if EJBs are deployed on every server in a cluster,
          then they MUST be configured to be clusterable. Why is that? Since
          they are running in the same JVM as the servlets, we don't want EJB load
          balancing or fault tolerance.. I would think that the non-clusterable
          EJBs would not be added to the the cluster-wide JNDI. Also, we have
          deployed this way in SP 5 and 6.0 SP2 and we never got any conflict
          errors. If we do need to make them clusterable, can someone explain
          why? Thanks.
          Kirk
          

Answer 1

If you're using WLS 9.x, then I would package the ejb-client-jar as a library.
If you're using an older version, then you have the 2 choices you mentioned (packaging it in each war file or putting in on the classpath.)
The advantage of the classpath is you have the file in only 1 place. The disadvantage is you must restart the server to update it.
Placing it in each webapp means you have N copies of the jar file, but you'll be able to take an update by just redeploying the webapp not restarting the entire server.
WLS 9.x's libraries give you the best of both worlds. You only manage 1 copy of the file, but you do not need to restart the server. You can also have multiple versions of a given library.
-- Rob
WLS Blog http://dev2dev.bea.com/blog/rwoollen/