Upgrading connections with IBM MQ
If you use the CICS®-MQ adapter, bridge, trigger monitor, or API crossing exit to connect CICS to IBM® MQ, you have some changes to make when you upgrade your version of CICS. This information applies to all currently supported CICS TS releases, regardless of your current release and the target release.
If you are upgrading from an end-of-service release, you might need to take additional actions that are relevant to your current, end-of-service release, along with the actions summarized in the upgrade instructions in this information. For details, see Upgrading from end-of-service releases.
Upgrade actions
Table 1 lists the actions you must perform when upgrading to a higher CICS release, regardless of your current release and the target release. The sections that describe these actions in detail are tagged with All versions.
| Action | Mandatory or optional? |
|---|---|
| Specify the new versions of IBM MQ libraries in the STEPLIB and DFHRPL concatenation | Mandatory |
| Replace existing mechanisms for managing instances of CKTI transactions with MQMONITOR resources | Optional |
| Replace existing mechanisms for managing instances of CKBR transactions with MQMONITOR resources | Optional |
Specify the new versions of IBM MQ libraries in the STEPLIB and DFHRPL concatenation
All versions
You must replace the existing versions of the IBM MQ libraries with the new ones in the STEPLIB and DFHRPL concatenation in your CICS procedure. The libraries are thlqual .SCSQAUTH, thlqual .SCSQCICS, and thlqual .SCSQLOAD, where thlqual is the high-level qualifier for the IBM MQ libraries. The SCSQAUTH library is included in both concatenations, but the SCSQLOAD library and the optional SCSQCICS library are included in the DFHRPL concatenation only. Include the IBM MQ libraries after the CICS libraries to ensure that the correct code is used.
Replace existing mechanisms for managing instances of CKTI transactions with MQMONITOR resources
All versions
To complement the existing MQCONN resource, CICS TS 5.4 introduced the MQMONITOR resource definition and new EXEC CICS and CEMT commands for the CICS-MQ monitor.
Before CICS TS 5.4, you cannot start more than one instance of CKTI against the same initiation queue from a single CICS subsystem. When the IBM MQ connection is disconnected and then reconnected, CKTI must be manually restarted.
The new MQMONITOR resource provides a better mechanism for managing instances of CKTI transactions. It is recommended that you replace existing mechanisms for managing instances of CKTI transactions with MQMONITOR resources. The benefits are as follows:
- You can have more than one MQMONITOR resource monitoring an MQ initiation queue. Any number of MQMONITOR resources can be defined and installed in a CICS region.
- An MQMONITOR can be configured to start the associated transaction (for example, CKTI) automatically when the MQ connection is established. Using the MQMONITOR resource removes the need to use the CKQC transaction to start and stop monitors manually.
- Configuration options include the ability to specify a transaction ID to be used by the monitor, the user ID under which a monitor task runs, and the user ID to be used by the monitor to start the application tasks if an alternative user ID is not provided by the application. These options allow better security controls.
Follow Setting up an MQMONITOR resource for the CICS-MQ bridge to define and install an MQMONITOR for monitoring an MQ initiation queue.
You can use new EXEC CICS and CEMT commands to work with the MQMONITOR resource definition. You can also use the SET MQMONITOR command to start and stop a CICS MQ monitor, as an alternative to issuing CKQC commands.
Replace existing mechanisms for managing instances of CKBR transactions with MQMONITOR resources
All versions
The recommended method of controlling the CICS-MQ bridge transaction CKBR is to use an MQMONITOR resource. Doing so allows the bridge to automatically restart when the connection to the IBM MQ manager is established.
Follow this procedure to set up an MQMONITOR for the CICS-MQ bridge.