The WebSphere® Application Server message migration utility uses an XA (globally coordinated) transaction to migrate messages from the V5 embedded messaging provider on a WebSphere Application Server Version 5.1 application server to the default messaging provider (service integration) on an application server at a later version of the product.
You do not have to start the Version 5.1 server.
You run the message migration utility only once for a particular queue, unless a failure occurs.
If a failure occurs during message migration, it is safe to run the message migration utility again in the same direction because messages are moved rather than copied. Whether you successfully try a failing message migration again, or delete the message, the message ordering of the remaining messages is preserved on the queue on the current version of the product.
During successful migration, messages are moved from the WebSphere Application Server Version 5.1 system to the later system. No copy is left on the Version 5.1 server queue.
For more information about the XA transaction, see XA recovery.
For information about the reversal of message migration, see Reversing the migration of messages by using the message migration utility.