When configuring number of MDBs concurrently processing messages, two parameters needs to be considered

• mdb-strict-max-pool - The number of MDB instances available to concurrently receive messages from the JCA RA's sessions - configured in EJB subsystem
• maxSession - The number of sessions the JCA RA can use concurrently to consume messages - configured by MDB Activation config property

Maximal number of concurrently processed messages equals to minimal value of these parameters.
In case number of MDBs needs to be adjusted, admin needs to update/check both parameters (located in different places)
It would be nice to align size of mdb-strict-max-pool and maxSession activation config property.
If maxSession is not specified, size of mdb-strict-max-pool should be used.

Customer story : because of performance reasons, I need to tweak number of concurrently running MDBs. Now I need to configure two separate parameters located in different places, and in large majority of cases it is best to set them to same value