IBM MQ release types: planning considerations

Within Passport Advantage® there are two separate eAssemblies for IBM MQ 9.4. One contains installation images for IBM MQ 9.4.0 Long Term Support release, and the other contains installation images for IBM MQ 9.4.x Continuous Delivery release. Download installation images from the eAssembly according to your choice of release.

All IBM MQ versions, and for IBM MQ 9.4 both the LTS releases and CD releases, belong to the same Product Id.

Entitlement to use IBM MQ extends across the entire product (PID), subject to the constraints of licensed components and pricing metrics. This means that you can choose freely between LTS release and CD release installation images for IBM MQ 9.4.

After you download an installation image from Passport Advantage, you should select for installation only the components for which you have purchased entitlement. See IBM MQ license information for further information about which installable components are included for each chargeable component.

You can install IBM MQ 9.4.0 LTS release and IBM MQ 9.4.x CD release on the same operating system image. If you do this, the components appear as separate installations, as supported by IBM MQ multi-version support. Each version has distinct sets of queue managers associated with that version.

Each new CD release is provided as an installation image. The new CD release can be installed alongside an existing release, or, an earlier CD release can be updated in place by the installer to the new release.

CD releases contain functional enhancements as well as the latest set of defect fixes and security updates. Each CD release is cumulative, and wholly replaces all prior ones for that version of IBM MQ. So you can skip a specific CD release if it does not contain any function that is relevant for your enterprise.

The LTS release is serviced by the application of fix packs, which provide defect fixes, and cumulative security updates (CSUs), which provide security patches. The fix packs and CSUs are made available periodically and are cumulative.

For CD, CSUs are produced for the latest CD release only, which might be on a subsequent version.

You might occasionally be directed by the IBM Support team to apply an interim fix. Interim fixes are also known as emergency or test fixes, and are used to apply urgent updates that cannot wait for the next maintenance delivery.

There are constraints and limitations but, generally, a single queue manager can be migrated from using LTS release code to CD release code, or from using CD release code to LTS release code, provided that the target release is higher than that in use prior to the migration.

When a queue manager starts running a CD release of code, the queue manager command level is updated to indicate the new release level. This means any new functions provided in the release are enabled, and you can no longer restart the queue manager using a code release with a lower VRM number.

When ordering IBM MQ for z/OS® 9.4, two separate features are offered on ShopZ. The features correspond to the LTS release and the CD release. Both features are applicable to the same product ID (PID). It is the product ID that is licensed, so where one feature is licensed, there is entitlement to use the alternative feature if required. When ordering, you select the feature corresponding with either the LTS release or CD release.

If you are selecting products for inclusion in a ServerPac, you cannot choose both the LTS release and CD release in the same ServerPac order, because the products cannot be installed by SMP/E in the same target zone.

If your queue manger is in a queue sharing group, when you upgrade to the latest CD version you must upgrade all queue managers in the group.

The command level of a queue manager is the three-digit VRM level. An IBM MQ program can call MQINQ, passing the MQIA_COMMAND_LEVEL selector, to get the command level of the queue manager it is connected to.

Because the releases use different FMIDs, you cannot update a CD release with maintenance for an LTS release or the other way round. Similarly, there is no way to switch a version of the product code from an LTS release to a CD release or the other way round. However, you can switch a queue manager between the release models. See Migration between LTS release and CD release.

IBM MQ for z/OS uses PTFs for Maintenance.

PTFs are specific to a particular set of libraries corresponding to specific release level. For UNIX System Services features (that is, JMS and WEB UI, Connector Pack, and Managed File Transfer) the z/OS PTFs are aligned directly with the Multiplatforms fix packs and cumulative security updates (CSUs). These fixes are cumulative, and are made available at the same time as the equivalent Multiplatforms fix pack or CSU.

CD CSUs are not usually made available between CD releases, but are included in the next IBM MQ for z/OS CD release. You can also contact support to request a ++USERMOD.

Other fixes on IBM MQ for z/OS are distinct fixes on particular parts. These fixes resolve specific issues, are not cumulative, and are made available as and when they are produced.

There are constraints and limitations, but generally a single queue manager can be migrated from using LTS release code to CD release code or from using CD release code to LTS release code provided that the target release is higher than that in use prior to the migration.

From IBM MQ for z/OS 9.2.0, you can migrate back and forth between CD and LTS releases with the same VRM as many times as needed, and without impact on the ability to backwards migrate. For example, a queue manager can be started up at IBM MQ for z/OS 9.3.0 LTS, then shut down and started up at IBM MQ for z/OS 9.3.0 CD, then shut down and started up at IBM MQ for z/OS 9.3.0 LTS.

IBM MQ for z/OS has traditionally provided a fallback capability (backward migration) so that after a period of running following a migration you can fall back to the prior release. This capability is retained for LTS releases, and those CD releases with a modifier of 0 such as 9.3.0 CD, but is not possible when the source or target of a migration is a CD release with a non-zero modifier number, for example, 9.2.5 or 9.3.1.