The X/Open Distributed Transaction Processing (X/Open DTP) model, designed by The Open Group (a vendor consortium), defines a standard communication architecture that provides the following:
Concurrent execution of applications on shared resources.
Coordination of transactions across applications.
Components, interfaces, and protocols that define the architecture and provide portability of applications.
Atomicity of transaction systems.
Single-thread control and sequential function-calling.
The X/Open DTP XA standard defines the application programming interfaces that a resource manager uses to communicate with a transaction manager. The XA interfaces enable resource managers to join transactions, to perform two-phase commit, and to recover in-doubt transactions following a failure.
OpenJPA supports XA-compliant transactions when used in a properly configured managed environment. The following components are required:
A managed environment that provides an XA compliant transaction manager. Examples of this are application servers such as WebLogic or JBoss.
Instances of a javax.sql.XADataSource for each of the
DataSources that OpenJPA will use.
Given these components, setting up OpenJPA to participate in distributed transactions is a simple two-step process:
Integrate OpenJPA with your application server's transaction manager, as detailed in Section 2, “ Integrating with the Transaction Manager ” above.
Point OpenJPA at an enlisted XADataSource, and configure
a second non-enlisted data source. See
Section 2.1, “
Managed and XA DataSources
”.