Disabling dynamic resource definition for MODBLKS resources

You might need to disable the dynamic resource definition (DRD) process for MODBLKS resources and fall back to using the online change process.

With DRD enabled, ensure that the IMS.MODBLKS data set has a complete set of the current resource definitions. This complete set includes resource definitions that were originally in the IMS.MODBLKS data set or in the RDDS at cold start, and that were not changed or deleted dynamically. It also includes any resource definitions that were added or changed dynamically since cold start. This check enables you to fall back to using online change for the IMS.MODBLKS data set with all the resources that were either defined originally by system definition or defined dynamically.

Perform the following procedure to disable the DRD process and fall back to using the online change process:

Procedure

  1. Use one of the following methods to synchronize your IMS.MODBLKS data set 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 MODBLKS system definition to update the IMS.MODBLKS data set.
    • Generate an RDDS for the IMS with the resource definitions at the IMS. Use the EXPORT command to export the definitions from IMS to an RDDS. When IMS is using the IMSRSC repository, the non-system RDDS can be generated using the EXPORT DEFN command or by using the Repository to RDDS utility (CSLURP20).

      Use the Resource Definition Data Set (RDDS) Extraction utility (DFSURDD0) to extract the resource definitions to create Stage-1 macro statements from the stored resource definitions in an RDDS. Then perform a MODBLKS system definition to update the IMS.MODBLKS data set.

  2. Shut down IMS normally.
  3. Enable online change for the IMS.MODBLKS data set:
    1. Perform one of the following steps:
      • Remove the MODBLKS keyword from the DFSCGxxx member of the IMS PROCLIB data set. Optionally, also remove the MODBLKS keyword from the COMMON_SERVICE_LAYER section of the DFSDFxxx member of the IMS PROCLIB data set.

        If both members are defined, any values specified in DFSCGxxx override those values that are in DFSDFxxx.

      • Change the value of the MODBLKS keyword from DYN to OLC in the DFSCGxxx member of the IMS PROCLIB data set. Optionally, also change the value of the MODBLKS keyword from DYN to OLC in the COMMON_SERVICE_LAYER section of the DFSDFxxx member of the IMS PROCLIB data set.

        If both members are defined, any values specified in DFSCGxxx override those values that are in DFSDFxxx.

    2. Specify AUTOIMPORT=MODBLKS or AUTOIMPORT=AUTO in the DFSDFxxx member of the IMS PROCLIB data set.
    3. Remove all RDDS statements from the DFSDFxxx member of the IMS PROCLIB data set. If the repository is not required for any other IMS functions, also remove all repository statements from the DFSDFxxx member.
      Important: If the repository statement is required for other IMS resources and AUTOIMPORT=AUTO is specified in the DFSDFxxx member, ensure that all of the MODBLKS resources are deleted from the repository.
  4. Ensure that the IMS JCL includes the MODBLKS DD statement.
  5. Cold start IMS. An IMS cold start creates runtime resource definitions from the stored resource definitions in the IMS.MODBLKS data set.
    The online change process for the IMS.MODBLKS data set is enabled again (and DRD is disabled). No variations of the CREATE and DELETE commands are allowed in a non-DRD environment. Some variations of the UPDATE command are allowed. You can issue an EXPORT DEFN TARGET(RDDS) command to export to a non-system RDDS.
  6. Reestablish your in-house procedures that use the online change process for the IMS.MODBLKS data set, and disable the in-house procedures that use DRD commands.
    If you have been using the repository and all IMS systems are falling back to the online change process, disable RM from using the repository and stop the RS address spaces.