This topic describes how to run the WebSphere message migration
utility.
Before you begin
- Ensure that you have a WebSphere Application Server Version 5.x, which
contains an embedded messaging server. You do not need
to start the WebSphere Application Server Version 5.x.
- Ensure that no applications are reading from the WebSphere Application
Server Version 5.x queue manager when you run the message migration utility.
- Ensure that you have not modified or deleted the message queues
on the WebSphere Application Server Version 5.x.
- Ensure that you have a running WebSphere Application Server version 6.0.x
that fulfils the following conditions.
- The WebSphere Application Server version 6.0.x is on the same host as
the WebSphere Application Server Version 5.x.
- The WebSphere Application Server version 6.0.x contains a messaging engine
on the bus to which the messages will migrate (this is automatically included
for you if you upgrade your server from Version 5 to version 6).
Note: These conditions are met if you run the message migration utility
at the correct point in the WebSphere Application Server migration sequence.
The correct point is after you have run the WASPostUpgrade command and restarted
the version 6 node.
Why and when to perform this task
Messages are migrated from the WebSphere Application Server version
5.x to the WebSphere Application Server version 6.0.x under an XA (globally
coordinated) transaction. For further information about the XA transaction
refer to XA recovery.
For
further information about the reversal of message migration, using the message
migration utility, refer to Reversing
the migration of messages using the WebSphere message migration utility.
During
successful migration, messages are moved from the WebSphere Application Server
Version 5.x to the WebSphere Application Server version 6.0.x, no copy is
left on the Version 5.x server’s queue.
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 retry a failing message migration, or
delete the message, the message ordering of the remaining messages is preserved
on the WebSphere Application Server version 6.0.x queue.
Steps for this task
- Follow the actions indicated by the message migration utility.
- On the panel called "Select the direction of migration" select Migrate
messages from Version 5.x to version 6.0.
- Select a message reliability to apply to messages that are to be
migrated. More details on the choice of reliabilities can be found in the Message Reliability Levels topic.
- It is possible to migrate multiple queues during a single execution
of the utility.
- You will need to run the migration utility more than once if the first
message migration attempt failed.
- If a queue has a failing message then perform one of the following operations:
- Retry the failing message, in case there is a transient error.
- Delete the failing message and go on to the next message.
- Stop the queue that has the failing message and move on to the next queue.