Start of change

Configuring global coordination of transactions (two-phase commit)

If you want to ensure data integrity during transactions by globally coordinating message flow transactions with a WebSphere MQ queue manager.

Before you start:
On distributed platforms (UNIX, Linux (x86 platform), and Windows), by default the broker manages all message flow transactions using a one-phase commit approach. In many contexts, this is sufficient but if your business requires assured data integrity (for example, for audit reasons or for financial transactions), configure your system so the broker's WebSphere MQ queue manager manages the message flow transactions in a two-stage commit approach using the XA protocol standard. For more information about global coordination of transactions, see The Transactional model.

z/OS platform On z/OS, all transactions are globally coordinated by RRS so the following instructions are not relevant. RRS must, however, be available. For more information, see Resource Recovery Service planning on z/OS.

To configure your system for global coordination of transactions:

  1. Ensure that the databases are configured for global coordination.
  2. Configure the broker environment so that the broker's queue manager coordinates transactions. The steps to configure the broker environment depend on the database manager that you are using and whether the broker's queue manager and the execution group are 32-bit or 64-bit.

    If you are using shared memory to connect directly to a 64-bit database instance, you must use a 64-bit queue manager to globally coordinate transactions (all WebSphere MQ Version 6 queue managers on 64-bit platforms are 64-bit). A 32-bit queue manager cannot connect directly to a 64-bit database instance.

  3. Configure the message flow for global coordination.
When you have completed all of the steps, your message flows are processed using global coordination, which is managed by the queue manager.

You must complete all of the steps correctly; otherwise, global coordination will not work.

For an example of how you can use WebSphere MQ to globally coordinate transactions, see the Error Handler sample in the Samples Gallery.
End of change