Invoking hiperbatch support

About this task

Hiperbatch is a z/OS performance enhancement that works with DLF (data lookaside facility) to allow batch jobs and started tasks to share access to a data set, or data object. IBM® Z Workload Scheduler provides control information to DLF concerning which operations are allowed to connect to which DLF object and which data sets are eligible for Hiperbatch.

Within IBM® Z Workload Scheduler, a data set eligible for Hiperbatch is treated as a special resource. Using the Special Resource Description dialog, you define a special resource with the name of the data set and specify Y (yes) in the Hiperbatch field. The DLF exit sample, EQQDLFX, can then make the following decisions about the DLF component:
  • Will this data set be eligible for Hiperbatch?
  • Should this operation be connected to this data object?

IBM® Z Workload Scheduler issues enqueues on the job and data set name to notify the DLF exit that the job to be scheduled will use Hiperbatch. When the job ends, IBM® Z Workload Scheduler checks if the same data set is required by the immediate successor operation or other ready operations. If the data set is not required, IBM® Z Workload Scheduler initiates purge processing (that is, IBM® Z Workload Scheduler removes the data object from Hiperspace™) also for operations that have ended in error, unless the keep on error value specifies that the resources allocated to the operations must be kept.

Only the system where the controller is started and systems participating in the same global resource serialization (GRS) ring interact with DLF. Before you can use IBM® Z Workload Scheduler Hiperbatch support, you must:
  1. Install the DLF connect/disconnect exit. SEQQSAMP member EQQDLFX contains an assembler program that provides control information to DLF based on information provided by IBM® Z Workload Scheduler. For details , see IBM Z Workload Scheduler: Planning and Installation.
  2. Add started-task procedure EQQPROC. When an object in Hiperspace™ is no longer needed by the jobs, IBM® Z Workload Scheduler initiates a PURGE of this object. A start command is issued from within IBM® Z Workload Scheduler:
    EQQPROC
    S EQQPROC, PARM='resource name
    (Sample installation JCL for this started task is contained in sample member EQQPROC.)
  3. Create a file containing purge JCL. EQQPROC initiates an IBM® Z Workload Scheduler batch program, EQQPURGE. EQQPURGE requires input JCL to submit to the JES internal reader. Sample member EQQJCLIN contains sample input JCL. When the DLF exit is installed on a z/OS system other than the IBM® Z Workload Scheduler controller, the JCL must contain routing information to transmit the job to the correct z/OS system.