There are three types of transaction resource managers:
Databases - Use of transactions prevents databases from being left in inconsistent states due to incomplete updates. For information about JDBC transaction isolation levels, see Using JDBC Transaction Isolation Levels.
The Enterprise Server supports a variety of JDBC XA drivers. For a list of the JDBC drivers currently supported by the Enterprise Server, see the Sun GlassFish Enterprise Server 2.1 Release Notes. For configurations of supported and other drivers, see Configurations for Specific JDBC Drivers in Sun GlassFish Enterprise Server 2.1 Administration Guide.
Java Message Service (JMS) Providers - Use of transactions ensures that messages are reliably delivered. The Enterprise Server is integrated with Sun GlassFish Message Queue, a fully capable JMS provider. For more information about transactions and the JMS API, see Chapter 18, Using the Java Message Service.
J2EE Connector Architecture (CA) components - Use of transactions prevents legacy EIS systems from being left in inconsistent states due to incomplete updates. For more information about connectors, see Chapter 12, Developing Connectors.
For details about how transaction resource managers, the transaction service, and applications interact, see Chapter 12, Transactions, in Sun GlassFish Enterprise Server 2.1 Administration Guide.