IMS HP Change Accumulation Utility address space considerations

IMS High Performance Change Accumulation Utility executes in a multiple address space environment.

The main job can be submitted by the user or by a job scheduler, or initiated as a started task. The job name is determined by the user. The authority is obtained from the user ID that is associated with the job.

IMS High Performance Change Accumulation Utility initiates the subordinate address spaces depending on the method specified for processing job tasks.

The following table describes the subordinate address spaces that can be directly initiated by IMS High Performance Change Accumulation Utility. It shows how the name is determined, how many can be started, and which JCL procedure is used to build the JCL.
Method Subordinate address space name Number started JCL procedure used
Custom job processing
  • The job name is determined by HPCA-ID prefix plus 4-character numeric suffix.
  • The prefix is determined by either:
    • The PARM specification hpca-id on the EXEC statement
    • The ID= hpca-id command value from HPCSYSIN
 The number of address spaces is specified by the PARALLEL SORTS = command value from HPCSYSIN. The default value is 9.
The job that was written either to the PROCLIB or JOBLIB library that is specified in HPCAPROC DD. The job name is stored as either:
  • hpca-id
  • ID= prefix plus 0001 – 0nnn
Standard job processing The job name is determined by either:
  • The PROC = name parameter on the EXEC PARM statement
  • The PROCEDURE NAME= name command value from HPCSYSIN.
 The number of address spaces is specified by the PARALLEL SORTS = command value from HPCSYSIN. The default value is 9. An IMS High Performance Change Accumulation Utility defined member is added to the PROCLIB / JOBLIB libraries during installation. The member name must match the name value specified on either:
  • PROC=
  • PROCEDURE NAME=
The member name is used to start all subordinate address spaces.
Started task control job processing The job name is determined by either:
  • The STC = name parameter on the EXEC PARM statement.
  • The STC NAME= name command value from HPCSYSIN.
 The number of address spaces is specified by the PARALLEL SORTS = command value from HPCSYSIN. The default value is 9. An IMS High Performance Change Accumulation Utility defined member is added to a user library during installation. The member name must match the name value specified on either:
  • STC=
  • STC NAME=
The member name is used to start all subordinate address spaces.
Single address space job processing No subordinate address spaces are created. Instead, each SORT process is an internal task in the main address space. The number of internal tasks is specified by the PARALLEL SORTS = command value from HPCSYSIN. However, IMS High Performance Change Accumulation Utility adjusts this value for managing private storage. The default value is 3. The internal task does not require a JCL procedure; however, the member name value on PROC= or PROCEDURE NAME= must specify HPCSTASK.
For more information about the listed parameters, see the IMS Recovery Solution Pack: IMS High Performance Change Accumulation Utility User's Guide.

All subordinate address spaces that are initiated by IMS High Performance Change Accumulation Utility require special RACF® rules to be set up to allow the job to have the appropriate level of authority. For details about setting up the proper authority and potential problems, see RACF considerations for subordinate address spaces.