This topic describes how to reverse the results of the WebSphere® message migration
utility.
Before you begin
If you want to revert to using WebSphere Application Server Version 5,
instead of WebSphere Application
Server Version 6, you must reverse the migration of the messages before
deleting the WebSphere Application
Server Version 6 server.
About this task
Reverse migration is carried out under XA coordination.
If
the reverse migration takes place after a partial migration from WebSphere Application Server
Version 5 to WebSphere Application
Server Version 6, in which only some of the messages were migrated,
then the message ordering will not be preserved. However, if the target
queue in the WebSphere Application
Server Version 5 is empty when the migration takes place (as it is
likely to be) then the message order will be retained.
Messages
that are reverse-migrated appear on the queue after those that were
not migrated at the first attempt.
Note:
- 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 WebSphere Application Server Version 6
queue.
Procedure
- Follow the actions indicated by the message migration utility.
- On the "Select the direction of migration" panel choose Reverse
a previous migration.
Results
As in normal migration, if a queue has a failing message you
have the choice of:
- Trying the failing message again, in case there is a transient
error.
- Deleting the failing message and going on to the next message.
- Stopping the queue that has the failing message and moving on
to the next queue.