Installing resources automatically

To automatically install a set of resources when a CICS® system initializes, you must:

  1. Update the CICS system definition (CICSSYS) to indicate:
  2. Create one or more resource descriptions (RESDESC) and specify:
  3. Optionally, associate the resource descriptions with resource assignments (RASGNDEF) to select specific resources and provide usage information and override values.

    In this case, the resources are installed in the CICS systems named in the Target Scope and Related Scope fields of the resource assignment, resource description, or the association between them.

Note:
Resources can be installed in a CICS system automatically even if the maintenance point CMAS for the CICSplex is not active.

Performance considerations for assigned resource descriptions

Each time a BAS resource definition is associated with a target CICS system through a RESDESC, an entry for that installation assignment is made in the resource set table which is an internal table within the BAS storage cache. Take the example of a data repository with just one RESDESC defined, which has 50 PROGDEFs associated with it in migration mode. When the target scope of the RESDESC is assigned to a single MAS, the resource set table will be initialized with 50 entries -- one entry for each PROGDEF instance at the target MAS. If the RESDESC target scope is changed to a CICS system group comprising 20 MASes, the number of entries in the resource set table will increase to 1000 (50 resource definitions times 20 target regions). The resource set table is kept in contiguous storage to optimize peformance. It follows that, because the BAS storage cache has a finite size, there is a limit on the number of installation assignments that can be made with RESDESCs within a CICSPlex. The limit will vary from installation to installation but the assignment of more than 150,000 resource definitions across the whole of the CICSPlex may lead to performance problems. If a CICSPlex is expected to exceed that limit, we advise you to consider reducing the number of static definitions by using autoinstall services.

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