Global transactions

If an application uses two or more resources, then an external transaction manager is needed to coordinate the updates to both resource managers in a global tansaction.

Global transaction support is available to web and enterprise bean J2EE components. Enterprise bean components can be subdivided into beans that exploit container-managed transactions (CMT) or bean-managed transactions (BMT).

BMT enterprise beans and web components can use the Java Transaction API (JTA) UserTransaction interface to define the demarcation of a global transaction. The UserTransaction interface is obtained by a JNDI lookup of java:comp/UserTransaction . The UserTransaction is not available to the following components:

• CMT enterprise beans. Any attempt by such beans to obtain the interface results in an exception in accordance with the EJB specification.

• Client applications running outside the Web and EJB containers.

Ensure that programs that perform a JNDI lookup of the UserTransaction interface, use an InitialContext that resolves to a local implementation of the interface. Also ensure that such programs use a JNDI location appropriate for the EJB version.

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Local transaction containment (LTC)
Transaction support in WAS