Migrating MSC macro definitions to the IMSRSC repository

You can migrate your MSC macro definitions to the IMSRSC repository to store the definitions in a single, centralized location for all IMS systems in an IMSplex. Migrating MSC definitions to the IMSRSC repository also ensures that the definitions are saved across an IMS cold start.

Procedure

To migrate MSC macro definitions to the IMSRSC repository, complete the following steps:

  1. Enable automatic export and automatic import by defining both of the following parameters in the DYNAMIC_RESOURCES section of the DFSDFxxx member of the IMS.PROCLIB data set:
    • AUTOEXPORT=AUTO or AUTOEXPORT=REPO
    • AUTOIMPORT=AUTO
  2. Enable dynamic resource definition for MSC resources by specifying MSCRSCS=DYN in the MSC section of the DFSDFxxx member. Also ensure that MODBLKS=DYN is specified in either or both of the following locations:
    • The DFSCGxxx member of the IMS.PROCLIB data set
    • The COMMON_SERVICE_LAYER section of the DFSDFxxx member of the IMS.PROCLIB data set
  3. Enable the IMSRSC repository for MSC resources by specifying MSCREPO=Y in the MSC section of the DFSDFxxx member.
  4. Specify attributes of the repository in the following members of the IMS PROCLIB data set:
    • FRPCFG member
    • BPE configuration parameters member
    • CSLRIxxx member
    • DFSDFxxx member
  5. Create the repository catalog pairs of data sets.
  6. Create the IMSRSC repository pairs of data sets.
  7. Start the Repository Server (RS) address space.
  8. Define the IMSRSC repository data sets to RS, which stores information about the IMSRSC repository in the RS catalog repository data sets.
  9. If you are enabling more than one IMS Resource Manager (RM), start the Common Queue Server (CQS) with a resource structure.
  10. Enable RM to use the IMSRSC repository dynamically.
    • If the RM address space is running, issue the UPDATE RM command.
    • If RM is not running, restart RM so that it connects to the RS address space.
  11. Specify the MSC=Y execution parameter in your startup procedure to initialize the MSC function.
  12. If one or more logical link paths are not defined in an MSNAME stage-1 system definition macro, specify the SYSID= parameter in the MSC section of the DFSDFxxx member to define one or more local system IDs (SYSIDs) for the IMS system.
  13. If you are cold starting IMS with IMSRSC repository support for MSC resources enabled for the first time and you want MSC resources to be automatically exported to the IMSRSC repository at the cold start, ensure that the following data sets contain the current MSC resource definitions:
    • The DFSCLL3x member of the IMS.SDFSRESL data set, for both MSC physical and logical link definitions
    • The DFSCLC0x member of the IMS.SDFSRESL data set, for MSC logical link path definitions
    • The DFSCLR0x member of the IMS.SDFSRESL data set, for remote logical terminal definitions
  14. Specify the EXEC parameters DFSDF=xxx and, if MODBLKS=DYN was specified in the DFSCGxxx member, CSLG=xxx. These parameters identify which DFSDFxxx and DFSCGxxx members in the IMS.PROCLIB data set to use.
  15. Cold start IMS.
    If the IMSRSC repository does not contain MSC resources, the MSC resource definitions that were generated during the system generation process are imported into the IMS system to create the runtime resource definitions. The runtime resource definitions are then automatically exported to the IMSRSC repository at the cold start.
    If one of the following conditions are true, ensure that at least one system identifier (SYSID) is specified in the MSC section of the DFSDFxxx PROCLIB member. Otherwise, IMS cold start abends with ABENDU0741 MODID MS0ABEND. At least one of the SYSIDs should be the lowest SYSID you plan to define for that IMS system.
    • AUTOIMPORT=AUTO is specified in the DYNAMIC_RESOURCES section of the DFSDFxxx member with no MSC resources in the IMSRSC repository and no MSC resources are defined in stage-1 system definition macros.
    • AUTOIMPORT=REPO is specified in the DYNAMIC_RESOURCES section of the DFSDFxxx member with no MSC resources in the IMSRSC repository.
    • AUTOIMPORT=NO is specified in the DYNAMIC_RESOURCES section of the DFSDFxxx member.
  16. Optional: Issue the QUERY command for the type of MSC resource that you exported to the IMSRSC repository with the SHOW(DEFN) keyword specified.
    The local definitions in the IMS system and the global definitions in the IMSRSC repository are displayed. All of the MSC resource attributes should be identical between IMS and the IMSRSC repository.
After you migrate MSC macro definitions to the IMSRSC repository, the MSC resource definitions that you create or update since the last automatic export are exported to the IMSRSC repository at the next IMS checkpoint. The IMS checkpoint can be initiated either by issuing the /CHECKPOINT command or automatically by the IMS system.

If you are using channel-to-channel (CTC) links, consider removing the DD definitions for the CTC links from the IMS JCL before you import the MSC resources from the IMSRSC repository. This allows the CTC addresses that are defined to be used for the CTC links that are imported from the IMSRSC repository.

If you use the IMSRSC repository to store dynamically defined MSC resources, the DFSCLL3x and DFSCLR0x members of the IMS.SDFSRESL data set are no longer required. Because the DFSCLC0x member might contain non-MSC resources, the DFSCLC0x might still be required. After you are satisfied with the setup of your DRD environment for MSC resources, the DRD environment is running successfully, and your MSC resources are exported to the IMSRSC repository, you can remove the DFSCLL3x and DFSCLR0x members. For the DFSCLC0x member, update the member to remove MSC logical link path definitions. If automatic import is enabled, MSC resource definitions are imported during IMS cold start from the repository that contains the most current data. However, you can continue to use the DFSCLL3x, DFSCLR0x, and DFSCLC0x members as the source for your MSC resource definitions, instead of a repository. If you continue to use the DFSCLL3x, DFSCLR0x, and DFSCLC0x members, keep your system definition macros synchronized with the changes you make dynamically using DRD commands.

If you migrate to using the IMSRSC repository for dynamically defined MSC resources but continue to use the DFSCLL3x, DFSCLR0x, and DFSCLC0x members of the IMS.SDFSRESL data set, keep resource definitions that are in the members synchronized with the resource definitions that are in the repository. This synchronization enables you to maintain viable DFSCLL3x, DFSCLR0x, and DFSCLC0x members if you must disable DRD and fall back to using the system generation process for MSC resources. To keep your DFSCLL3x, DFSCLR0x, and DFSCLC0x members synchronized with your online definitions, update your static macro definitions with the changes that you make dynamically using type-2 commands. When changes are made dynamically, perform a MSC system definition to add, change, or delete resources from the DFSCLL3x, DFSCLR0x, and DFSCLC0x members.