In EJB conatainer, how to manage MDB, Will it create one thread for one MDB?

Question

MDB has to waiting for message to arraive, so it must to do something "waiting" then block the running thread.

so, In EJB conatainer, how to manage MDB, Will it create one thread for one MDB?

Answer 1

Every EJB and MDB is pooled, for consuming messages is still valid:

... JMS messages are processed concurrently. That is, although each bean instance handles a message at a time, the EJB container takes care of creating enough bean instances to handle the message load at a given moment. In WebLogic you can set the initial number and max number of bean instances created by the container. For more information, see the @MessageDriven Annotation.

Source: http://docs.oracle.com/cd/E11035_01/workshop102/ejb/messagedriven/conGettingStartedWithMDBs.html