Single Threaded MDB on Glassfish

Question

I have a number of MDBs running on Glassfish 3.1.2.2. Due to the nature of work on one of the MDBs I need to make it single threaded. I looked at the Tuning Guide, and while setting the maximum pool size to 1 does resolve the problem, it also means all the other MDBs are single threaded. What I'd really like to do achieve is for the specific MDB to be single threaded, whilst allowing the others to be multi-threaded.

Answer 1

That's easy to achieve via the glassfish-ejb-jar.xml deployment descriptor:

<glassfish-ejb-jar>
  <enterprise-beans>
    <ejb>
      <ejb-name>YourMDB</ejb-name>
      <bean-pool>
        <resize-quantity>1</resize-quantity>
        <max-pool-size>1</max-pool-size>
        <steady-pool-size>1</steady-pool-size>
      </bean-pool>
    </ejb>
  </enterprise-beans>
</glassfish-ejb-jar>

The above section will limit the number of processing beans to strictly 1, regardless of what the global poolsize says. That way you can easily finetune the system setup.