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Java Transaction API (JTA) UserTransaction

The Java Transaction API (JTA) UserTransaction type allows JDBC, JMS, ActiveEnterprise Adapter (using JMS transports), and EJB activities to participate in transactions. JTA specifies standard Java interfaces between a transaction manager and the parties involved in a distributed transaction system: the resource manager, the application server, and the application. Sun Microsystems developed and maintains the API. See http://java.sun.com/products/jta/ for more information about the API.

For activities that use the JMS transport, request/reply operations cannot participate in a JTA transaction.

Using this type of transaction requires an installed and configured application server that implements the JTA interface javax.transaction.UserTransaction. For example, the following transaction servers implement the JTA transaction interface:

•	BEA WebLogic Application Server

•	IBM Websphere Application Server

•	JBoss Application Server

Not all application servers permit JMS and JDBC operations to participate in the JTA transaction. Refer to your application server documentation for more information about supported operations. If the application server does not permit an operation, TIBCO ActiveMatrix BusinessWorks still allows you to configure the operations in the transaction. However, no exception is raised and the operations that are not supported by the application server are performed independent of the transaction.

If the transaction commits, all eligible activities in the transaction group commit. If the transaction rolls back, all eligible activities in the transaction group roll back. The transaction group commits automatically if all activities in the group complete and a non-error transition is taken out of the transaction group. If any errors occur while processing the activities in the group, even errors in activities that do not participate in the transaction, the transaction is rolled back and an error is returned. You should create an error transition out of the group to handle this situation.

Configuring JTA UserTransaction Transactions

To configure a JTA UserTransaction, select JTA UserTransaction as the transaction type of the group.

JDBC Connections used by JDBC activities in the transaction group must be configured to use JNDI as the connection type and specify the data source in the application server. Activities that use the JMS transport must be configured to use the XA connection factory in the application server. The JNDI configuration for JMS, EJB, or JDBC activities must specify the appropriate connection and JNDI Context information for the application server.

The JTA UserTransaction transaction group has the following fields on the transaction group’s Configuration tab:

Field	Description
Transaction Manager	A JTA UserTransaction shared configuration resource. See TIBCO ActiveMatrix BusinessWorks Palette Reference for more information about this resource.
Include Checkpoint	When this field is checked, an implicit checkpoint is performed after the last activity in the group completes successfully and before the transaction is committed. The deployment configuration must specify a database for storing process engine information and the JDBC Connection used must specify JNDI as the connection type for this checkpoint to participate in the transaction.
Checkpoint Duplicate Key	When the Include Checkpoints field is checked, you can specify a duplicate key in this field to perform duplicate checking. This is useful if the checkpoint included in the transaction is the first checkpoint in the process definition. If the process engine crashes after the checkpoint, restarted process instances can use the duplicate key to determine if the transaction has already committed. See Detecting Duplicate Process Instances for more information about specifying duplicate keys.

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