Custom pool not working when applied to Message-Driven Bean

1) Create a JMS Queue: jms-queue add --queue-address=customQueue --entries=java:jboss/jms/customQueue 2) Create a custom pool with a max-pool-size greater than the default (let's use 50): /subsystem=ejb3/strict-max-bean-instance-pool=customPool/:add(max-pool-size=50,timeout=5,timeout-unit=MINUTES) 3) Create a WAR application with an MDB and assign the annotation @Pool("customPool") to the MDB and also @ActivationConfigProperty(propertyName = "maxSessions", propertyValue = "50") to match the pool max size. Add a Thread.sleep to the onMessage() method to simulate. @MessageDriven(name = "CustomMDB" , activationConfig = { @ActivationConfigProperty(propertyName = "destinationType" , propertyValue = "javax.jms.Queue" ), @ActivationConfigProperty(propertyName = "destination" , propertyValue = "java:jboss/jms/customQueue" ), @ActivationConfigProperty(propertyName = "maxSessions" , propertyValue = "50" ) }) @Pool( "customPool" ) public class DummyListener implements MessageListener { private static AtomicInteger count = new AtomicInteger(); @Override public void onMessage(Message message) { try { System .out.println( "Count: " + count.incrementAndGet()); Thread .sleep(10000); } catch (InterruptedException e) { e.printStackTrace(); } } } @Pool annotation needs the following dependency: <dependency> <groupId> org.jboss.ejb3 </groupId> <artifactId> jboss-ejb3-ext-api </artifactId> <version> 2.2.0.Final </version> <scope> provided </scope> </dependency> 4) Deploy the application and send 50 messages to the queue. @Stateless @Path( "/enqueue" ) public class DummyResource { @Inject @JMSConnectionFactory( "java:/JmsXA" ) private JMSContext context; @Resource(mappedName = "java:jboss/jms/customQueue" ) private Queue customQueue; @GET public void get() { IntStream.range(0, 50).forEach(i -> context.createProducer().send(customQueue, "message" )); } } Only 15 queue messages will be dequeue at a time, not the 50 that was specified in the pool. I also don't know why 15, since the default MDB pool is configured to be 20.