Choosing a migration path

When you are migrating between IBM MQ Version 8.0 and Version 9.0, there are several migration paths you can take.

This topic gives an overview of the following migration paths:

  • Single-stage path, also known as Stand-alone, migration
  • Side-by-side migration path
  • Multi-stage migration path
Note: This scenario describes only the Single-stage and Side-by-side migration methods. Consider the advantages and limitations of each path to determine which best suits your requirements:

    Single-stage migration

    In single-stage migration, the installation of the latest version of the product replaces an earlier version in the same installation location.

    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 switch from loading the libraries from the earlier version, to loading the libraries of the latest version, automatically. Using this approach, your system will be unavailable for the entire process.

    Side-by-side migration

    In side-by-side migration, you install the latest version of IBM MQ alongside queue managers that continue to be associated with the earlier version.

    When you are ready, you migrate the queue managers, and applications to the latest version.

    With this approach, because you uninstall the earlier version before starting any queue managers, we can assign an installation of the latest version to be the primary installation.

    See Choosing a primary installation for further information.

    Multi-stage migration

    In multi-stage migration, you install the latest version of the product alongside running queue managers that continue to be associated with the earlier version. We can create queue managers and run new applications using the latest version installation. When you are ready to start migrating queue managers and applications from the earlier, we can do so, one-by-one. When migration to the latest version is complete, uninstall the earlier version, and make the latest version installation the primary installation.

    With the multi-stage approach, until you uninstall the earlier version, you must configure an environment to run applications that connect to a queue manager to the latest version. You must also provide a path to run IBM MQ commands. Both these tasks are accomplished with the setmqenv command.