Configuring global coordination of transactions (two-phase commit)

Globally coordinate message flow transactions with a WebSphere® MQ queue manager to ensure the data integrity of transactions.

Before you start:

Complete the following tasks:

On distributed platforms, the default behavior of the broker is to manage all message flow transactions by using a one-phase commit approach. In many contexts this approach is sufficient, but if your business requires assured data integrity (for example, for audit reasons or for financial transactions), configure the broker's WebSphere MQ queue manager to manage the message flow transactions in a two-stage commit approach by 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 Resource Recovery Service (RRS), therefore the instructions in this topic do not apply. RRS must, however, be available; 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. For information about how to perform this configuration, see Configuring databases for global coordination of transactions.
  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. For information about how to perform this configuration, see Configuring globally coordinated message flows.
When you have completed these steps, your message flows are processed by using global coordination, which is managed by the queue manager.

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

For an example of how you can use WebSphere MQ to globally coordinate transactions, look at the following sample: You can view samples only when you use the information center that is integrated with the Message Brokers Toolkit.
Related concepts
The Transactional model
Related tasks
Configuring globally coordinated message flows
Configuring databases for global coordination of transactions
Resource Recovery Service planning on z/OS
Enabling ODBC connections to the databases
Creating a broker
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Copyright IBM Corporation 1999, 2009Copyright IBM Corporation 1999, 2009.
Last updated : 2009-01-07 15:21:50

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