Dynamic IMS connectivity to MQ via Subzero

This implementation procedure requires the implementation of an IMS usermod, and subsequent stop and restart of IMS. It offers the following additional features:

• You do not need to modify any IMS SSM member parameters. IMS SSM parameters are modified in real-time based upon Subzero definitions and MQ subsystem availability.

• IMS can connect to local MQ subsystems using native IBM interfaces and remote MQ subsystems using Subzero.

  For example, IMSA on SYSA may have a SSN=MQB definition.

  If MQB is running on SYSB, Subzero will make the remote connection without the use of any native MQ interfaces.

  If MQB is running on SYSA, Subzero will simply pass the connection to the native MQ interface routines without any further execution of Subzero code. 

To create a dynamic connection to MQ via Subzero

1. Apply the IMS usermod:

   1. Edit the usermod - BRDSMP01. It can be found in SAMPLIB.Modify the following elements as instructed within the JCL:
      • Subzero high-level qualifier
      • IMS Distribution load library
      • IMS RESLIB
      • IMS SMP/E CSI
      • IMS SMP/E Target Zone
      • Modify the ++VER to specify only the entry for the correct IMS version

   2. Run the job. By default, this does an APPLY CHECK of the usermod. If the APPLY CHECK is successful, you can remove the CHECK parameter and rerun the job.

      Warning

      Note

      Do not accept this usermod. Reject this usermod before applying IMS maintenance and then re-apply the usermod afterwards.

   • Change your IMS startup JCL:

     1. Add the Subzero product library to the DFSESL statement in your IMS Control Region JCL.
     2. Add the Subzero product library to the DFSESL DD statement in your IMS Dependent Region JCL.

     Warning

     Note

     Subzero does not require any MQ load libraries for remote connectivity. You can remove the MQ load libraries from the DFSESL DD statement only if IMS never connects to a local MQ subsystem.

     If you want to remove all MQ libraries from the LPAR containing the IMS subsystem, you must replace the default SCSQDEFV table which maps queue manager names to their LIT values.

     Use one of the following methods:

     • Copy the default SCSQDEFV table from SCSQAUTH to the dependent region STEPLIB
     • Assemble and link your own version of the SCSQDEFV table
2. Stop and re-start IMS.

3. You should see the following messages:

    BMCBRDM0026I MQID connection is being managed by Subzero (DBCID)

    CSQQ000I IMS/TM IMSID connected to queue manager MQID
4. Restart your IMS dependent regions.
5. Set up the Subzero MQ redirection options in the LGC.See Setting-Subzero-configuration-options-in-LGC.