What Is the BEA Tuxedo Transaction Manager (TM)?

A resource manager (RM) is a data repository, such as a database management system or the Application Queuing Manager, with tools for accessing the data. The BEA Tuxedo system uses one or more RMs to maintain the state of an application. For example, bank records in which account balances are maintained are kept in an RM. When the state of the application changes through a service that allows a customer to withdraw money from an account, the new balance in the account is recorded in the appropriate RM.

The BEA Tuxedo system helps you manage transactions involving resource managers that support the XA interface. To coordinate all the operations performed and all the modules affected by a transaction, the BEA Tuxedo system plays the role of the Transaction Manager (TM).

The TM coordinates global transactions involving system-wide resources. Local resource managers (RMs) are responsible for individual resources. The Transaction Manager Server (TMS) begins, commits, and aborts transactions involving multiple resources. The application code uses the normal embedded SQL interface to the RM to perform reads and updates. The TMS uses the XA interface to the RM to perform the work of a global transaction.

The following table summarizes the actions taken by the Transaction Manager on behalf of each transaction.

Actions Performed by the Transaction Manager

When . . .	The Transaction Manager . . .
The application launches a transaction	Assigns a global transaction identifier (GTRID) to the transaction.
Other processes communicate with the process that launched the transaction	Tracks those communication partners.
The RM is accessed as part of the work of the transaction	Passes the appropriate GTRID to the RM so the RM can monitor which database records are being accessed for the transaction.
The application signals that a transaction is to be committed	Performs a two-phase commit protocol. Specifically, it: (a) contacts communication partners during Phase 1, (b) logs the successful outcome of Phase 1, and (c) contacts partners in Phase 2.
The application indicates that the transaction is to be aborted	Executes a rollback procedure.
A failure occurs	Executes a recovery procedure.