Ok, perhaps the correct question is: Does EJB3 persistence honors this aspects of Entity Bean Life Cycle (these behaviour is described in http://www.ubookcase.com/book/Sams/JBoss.4.0.The.Official.Guide/067232648...): anonymous wrote : With the default configuration of JBoss there is only one active instance of a given entity bean in memory at one time and the locking policy defined in each container configuration in standardjboss.xml: <locking-policy>org.jboss.ejb.plugins.lock.QueuedPessimisticEJBLock</locking-policy> I think if this two pieces are honored, then all I have to assure is the proper container-configuration (Standard CMP 2.x EntityBean) is in effect on my entity bean, what do you think?? please keep in mind by any means I'm not suggesting any disrespect via disinformation. I'm just kindly asking for some insight about this pessimistic locking issue, which at some point one self have to face. regards, PS: The reason I formulate the question as that is because the book Pro EJB3 JPA says the JPA doesn't support a portable way to do pessimistic locking. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4128156#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...