I have some questions regarding the actual working of singleton MDB. We have JBoss 4.0.5 GA clustered environment with two nodes (server1 and server 2) in the cluster. We have implemented a singleton MDB. Given below is a brief about the steps that we followed
1. Defined a queue (SequentialQ)
2. Created a MDB (SequentialMDB), which is attached to the SequentialQ
3. Deployed the SequentialMDB jar file under deploy-hasingleton folder on both the servers in the cluster
In jboss.xml the tag is set as true for the SequentialMDB. Based on our testing it seems everything is working fine.
Now my questions are
1. Since it is a singleton MDB, I understand there will be only one instance of it. But since the jar file is deployed on both servers, does both the server will have an instance of SequentialMDB?
2. If a message comes on SequentialQ, which node will process it?
3. Is it only the primary node on which the SequentialQ is present process the messages in case of singleton MDB's?
4. If the MDB is not singleton, does it get processed by the instances on both the nodes because we have the tag true?
Your answers are appreciated