I am using EJB3 with Jboss and when I shutdown my jboss server, all my tables and data is cleaned up.
Is it the normal behavior, how do I change this behavior?
Look at your %JBOSS_HOME%\server\default\<your_config>\ejb3.deployer\META-INF\persistence.properties
file, my guess is that you have the following line in that file: hibernate.hbm2ddl.auto=create-drop. If you don't want the database to be dropped when you shutdown JBoss, change the value to create or to the value that fits your needs.