The pool for message-driven beans is similar to the pool for session beans described in To configure EJB pool settings. By default, the container maintains a pool of message—driven beans.
To adjust the configuration of this pool:
In the tree component, select the Configuration node.
Select the EJB Container node.
Click the MDB Settings tab.
Under Pool Settings in the Initial and Minimum Pool Size field, enter the minimum number of message beans the container creates in the pool.
In the Maximum Pool Size field, enter the maximum number of beans the container maintains in the pool, at any time.
In the Pool Idle Timeout field, enter the time, in seconds, that a bean in the pool can remain idle before it is removed from the pool.
Restart the Application Server.