How to limit the maximum number of concurrently executing su

[ssrrll]

Hi guys,
I have a durable topic with 9 mdbs subscribed to. But dead lock encountered on acknowledging of a new message. Although nearly all operations successfully done at the first retry by PersistenceManager, there is a possibility that the operation fails. Is there any place that the maximum number of concurrently threads for one topic can be set?

Thanks!

[byorn]

Please explain how you are handling the transactions?

[ssrrll]

Thanks for your reply! :)
It's container managed. The MDBs do nothing in the testing environment. The error message is shown below:

java.sql.SQLException: null, message from server: "Deadlock found when trying to get lock; try restarting transaction"

org.jboss.resource.adapter.jdbc.WrappedPreparedStatement.executeUpdate(WrappedPreparedStatement.java:251)
at org.jboss.mq.pm.jdbc2.PersistenceManager.remove(PersistenceManager.java:1401)
at org.jboss.mq.server.BasicQueue.acknowledge(BasicQueue.java:749)
at org.jboss.mq.server.JMSTopic.acknowledge(JMSTopic.java:349)

I got this exception even though both parameters MaximumSize and MinimumSize of container invoker "message-driven-bean" set to 1 and MDB container parameter "MaximumSize" set to 1 with "strictMaximumSize" set to true