Entity Beans are CMT i.e. where Transactions are managed by Container.
Each method invokation on an
ejb either starts a new transaction or is part of previous transaction. CMP beans must be part of a transaction. This transaction scope is specified by transaction attribute in deployment file. The transaction ends before the method which started the transaction, ends. if successful, it commits before the end of method, otherwise rolledback and throws TransactionRolledbackException or RemoteException or TransactionRolledbackLocalException is thrown depending upon the case.