CICSPlex SM workload management

CICSPlex® SM workload management can dynamically route transactions and programs to the CICS® region that is the most appropriate at the time, taking into account any transaction affinities and workload separation definitions that exist.

CICSPlex SM workload management takes account of three main criteria when it selects a target for the workload:
  • Routing
    The process by which it decides the most appropriate target region to distribute the work to, assuming:
    • The work could be sent to any of the target regions.
    • The work does not impose any constraints on the distribution.
    • In cooperation with z/OS® Workload Manager, the region that is most likely to fulfill the response time goals.
  • Workload separation
    The process of distributing specified work to a specific set of target regions.
    • For example, separation of work by application type.
  • Affinity management
    Routing workloads that have existing dependencies declared for them.
    • For example, state data that is maintained in a single region.
    Eliminate all affinities if at all possible.

Workload management makes the best use of the available CICS systems, and provides opportunities for increased throughput, performance, and region health by routing transactions or programs among a group of target regions according to the availability, performance, and load of those target regions.

The CICSPlex SM workload management function uses a user-replaceable dynamic routing program, EYU9XLOP, to identify which target region runs a work request that originates in a requesting region. The region where the decision is made is called a routing region. The same region can be both the requesting and the routing region. For more information about dynamic routing with CICSPlex SM, and dynamic routing program EYU9XLOP, see Dynamic routing with CICSPlex SM.

The target region can be selected by using one of four algorithms:
  • The queue algorithm routes work requests to the target region that has the shortest queue of work, is least affected by conditions such as short-on-storage, and is the least likely to cause the transaction to abend.
  • The goal algorithm routes work requests to the target region that is best able to meet the transaction's response time goal, as predefined in z/OS Workload Manager. Before CICS TS 4.1, CICSPlex SM only supported average response time goals. However, CICS TS 4.1 and later adds the ability to also use percentile response time goals.
  • The link neutral queue (LNQUEUE) algorithm corresponds to the queue algorithm, except that the type of connection between the routing and target region is not considered.
  • The link neutral goal (LNGOAL) algorithm corresponds to the goal algorithm, except that the type of connection between the routing and target region is not considered.

For more information about CICSPlex SM workload management, see Managing workloads. For more information about configuring CICSPlex SM workload management, see Configuring workload management.