Migrating a queue manager to a later version on AIX and Linux

Single-stage migration

Single-stage migration is the term used to describe replacing the only installation of IBM MQ on a server, with a later release. Single stage migration is also known as upgrading in place or in place upgrade. Single-stage migration preserves existing scripts and procedures for running IBM MQ the most. With other migration scenarios you might change some scripts and procedures, but you can reduce the effect queue manager migration has on users.

The advantage of single-stage migration is that it changes the configuration of a queue manager on the earlier version as little as possible. Existing applications automatically switch from loading the libraries from the earlier version to loading the libraries of the later version. Queue managers are automatically associated with the installation on the later version. Administrative scripts and procedures are affected as little as possible by setting the installation to be the primary installation. If you set the installation of the later version to be the primary installation, commands such as strmqm work without providing an explicit path to the command.

For more information about performing a single-stage migration, see Migrating on AIX and Linux: single-stage.

Side-by-side migration

Side-by-side migration is the term used to describe installing a later version of IBM MQ alongside an earlier version on the same server. Queue managers remain running during the installation and verification of the later version of IBM MQ. They remain associated with the earlier version of IBM MQ. When you decide to migrate queue managers to the later version of IBM MQ, you stop all queue managers, uninstall the earlier version, and migrate them all to the later version of IBM MQ.

The advantage the side-by-side scenario has over the single-stage scenario is that you can install and verify the installation of the later version of the product on the server before switching over to it.

The side-by-side migration scenario is less flexible than multi-stage migration, and might not seem to have any advantages over it. However, side-by-side migration does have advantages over the multi-stage and single-stage approaches. With the side-by-side approach, because you uninstall the earlier version before starting any queue managers, you can assign an installation on the later version to be the primary installation. In the multi-stage approach, you cannot set an installation of the later version to be the primary installation while you continue to run the earlier version. With the later version having the primary installation, many applications restart without reconfiguring their environment, making the migration process simpler.

For more information about performing a side-by-side migration, see Migrating on AIX and Linux: side-by-side.

Multi-stage migration

Multi-stage migration is the term used to describe running a later version of IBM MQ alongside an earlier version on the same server. After installing the later version alongside the earlier version, you can create new queue managers to verify the installation of the later version, and develop new applications. At the same time, you can migrate queue managers and their associated applications from the earlier version to the later version. By migrating queue managers and applications one-by-one, you can reduce the peak workload on staff managing the migration. When migration to the later version is complete, you can uninstall the earlier version, and make the later version installation the primary installation.

For more information about performing a multi-stage migration, see Migrating on AIX and Linux: multi-stage.