Possible transaction types for EJB3 Session beans are listed below along with the behavior at transaction propagation ...
By default the Transaction Attribute is set to REQUIRED for MDB's even...
so it's better to annotate MDB's onMessage () as NOT_SUPPORTED as a precaution for
transaction timeouts.(if actual transaction is not required..!) most of the times for method calls that wait a longer time..
| Transaction Attribute | Caller Transaction Exists | Effect |
| REQUIRED | No | Container creates a new transaction |
Yes | Method joins the callers transaction | |
| REQUIRES_NEW | No | Container creates a new transaction |
Yes | Container creates a new transaction and the callers transaction is suspended | |
| SUPPORTS | No | No transaction is used |
Yes | Method joins the callers transaction | |
| MANDATORY | No | javax.ejb.EJBTransactionRequiredException is thrown |
Yes | Method joins the callers transaction | |
| NOT_SUPPORTED | No | No transaction is used |
Yes | The callers transaction is suspended and the method is called without a transaction | |
| NEVER | No | No transaction is used |
Yes | javax.ejb.EJBException is thrown |
