Support for Distributed Transactions

• The EJB container is capable of handling the distributed transactions for the beans
• The EJB server takes a role of the transaction coordinator
• Transaction support in EJB is based on the Java Transaction Service (JTS). JTS is to a large extent the Java mapping of CORBA's Object Transaction Service (OTS).
• The Java Transaction Service (JTS) takes care of coordinating all resources involved in a transaction (commonly by two-phase commit approach)
• Transaction policies of the bean are most often defined during the deployment process using declarative statements. In this case, the EJB container explicitly manages the start, commit and rollback of a transaction
• The bean may choose to implement a interface through which the container notifies it about significant events of the transaction
• Optionally, transactions can be controlled by the client application and the bean itself