Balancing a workload

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Start of changeThis example describes how to use the Web User Interface (WUI) to get CICSPlex® SM to balance a workload--that is, to route all work from a single routing region to a suitable target region. For this task, a "suitable" target region is the one with the shortest queue of work requests, relative to the maximum number of tasks permitted in the target region. This queue of work, also called the load count, is the queue of all active and queued user tasks. By default, tasks queued for both MAXTASKS and TRANCLASS are included in the load count. Use of the WLMLOADCOUNT EYUPARM allows sites to exclude tasks queued for TRANCLASS from the load count. Please refer to the CICS® Transaction Server for z/OS® Installation Guide (GC34-6426) for more information about the WLMLOADCOUNT EYUPARM.End of change

The TOR (CICSPT01) is the requesting region and the routing region, and the three AORs (CICSPA01, CICSPA02, and CICSPA03) are all target regions. None of the CICS regions are currently running.

If some of your work requests can’t be routed freely (perhaps you want work requests from a particular user always to go to the same target region, for example), don’t worry. You’ll see how to add that requirement in a later example task (Routing a specific transaction to a specific target region).

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  1. Create a CICS system group.

    The group will include all of the target regions among which the work requests ("the workload") can be routed dynamically.

    1. Click Administration views-->Topology administration views-->CICS system group definitions to open the System group definition tabular view
    2. If the current context is not PLXPROD1, specify PLXPROD1 in the Context field and click Refresh.
    3. Click the Create button to open the System group definition create screen.
    4. Type in the following:
      System group name
      CSGTGTS1
      Description
      All target regions in CICSplex PLXPROD1
    5. Click Yes to create the system group

      The System group definition tabular view is redisplayed, this time showing an entry for CICS system group CSGTGTS1.

    At this point, the group CSGTGTS1 exists, but is empty. The next step is to tell CICSPlex SM which target regions belong to the group.

  2. Add target regions to CICS system group CSGTGTS1.
    1. Click Administration views-->Topology administration views-->CICS system definitions to open the CICS system definition tabular view
    2. Select the entries for the CICS systems CICSPA01, CICSPA02 and CICSPA03 and click the Add to CICS system group button.
    3. In the Group which member will join field type in CSGTGTS1 and click the button labelled Yes to 3 remaining. This adds the three selected systems to your new group.
  3. Create a workload specification.
    1. From the main menu click Administration views-->Workload manager administration views-->Workload specifications to open the Workload management specification tabular view.
    2. Click the Create button and provide the following information:
      WLM specification name
      WLSPAY01
      Description
      Balance payroll workload in PLXPROD1
      Primary search criterion
      USERID
      Default target scope
      CSGTGTS1
      Algorithm type
      QUEUE
      Leave the remaining fields empty or accept the defaults.
      Notes:
      1. A Primary search criterion value of USERID is shown in this example, though in fact it does not matter whether you specify USERID or LUNAME, because the Primary search criterion value has no effect on simple workload balancing. It is used only for some kinds of workload separation, which is the subject of a later example. You have to supply a value because CICSPlex SM doesn’t know, at this stage, that you aren’t going to use this workload specification for workload separation.
      2. The Default target scope value is the name of the single target region, or group of target regions, to which work requests can be routed.
      3. The Algorithm type value, QUEUE, tells CICSPlex SM to select the target region that has the shortest queue of work requests.
      4. The Description is optional, but is worth providing. (When you are confronted with a list of specification names, and have no way of telling one from another, you will appreciate its value.)

    Click Yes. The Workload management specification tabular view is redisplayed, this time showing an entry for the new WLM Specification, WLSPAY01.

  4. Associate the workload specification with a routing region.

    The next step is to tell CICSPlex SM about the region that is going to be routing the work requests to the target regions in group CSGTGTS1.

    1. In the Workload management specification view, select the entry for the WLSPAY01 specification, and click Associate CICS system.
    2. In the CICS system field, enter the name of the routing region (CICSPT01, in this example) and click Yes.

    You can check that the association between the routing region and the workload specification has worked by selecting the entry for WLSPAY01 in the Workload management specification tabular view to open a detail view of WLSPAY01, then clicking CICS systems associated with this workload specification.

  5. Activate workload balancing in the routing region.
    1. From the main menu click Administration views-->Topology administration views-->CICS system definitions to open the CICS system definition tabular view.
    2. Select the entry for CICSPT01 and click the Update action button to open a detail view of CICSPT01.
    3. Scroll down to the Start of changeWorkload manager statusEnd of change field and select YES from the drop-down menu. Click the Yes button at the bottom of the screen to return to the CICS system definition tabular view.

      This change takes effect when the Start of changerouting End of changetarget region CICSPT01 is next started.

  6. Activate workload balancing in the target regions.
    1. From the CICS system definitition tabular view, select the entry for CICSPA01 and click the Update action button to open a detail view of CICSPA01.
    2. Scroll down to the Start of changeAOR dynamic routing modeEnd of change field and select YES from the drop-down menu. Click the Yes button at the bottom of the screen to return to the CICS system definition tabular view.

      This change takes effect when the target region CICSPA01 is next started.

    Repeat this step for target regions CICSPA02 and CICSPA03.

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When the routing region and the target regions have been started, you can check that the workload is active by clicking Active workload views-->Active workloads. This opens the Active workload view, showing the workload specification WLSPAY01 as active.

To see which target regions are being routed to, click Active workload views-->Target regions in an active workload. The displayed view is shows all active target regions being routed to within workload WLSPAY01. All of the target regions listed belong to the CICS system group CSGTGTS1.

Related concepts
Workload management and dynamic routing
Workload requirements
Establishing a workload
Balancing the work in a workload
Separating the work in a workload
Taking affinity relations into consideration
Related tasks
Adding a region to an existing target region scope
Removing a region from a target region scope
Adding a routing region to an active workload
Quiescing a target region in an active workload
Routing a specific transaction to a specific target region
Routing particular transactions from a given user to a specific target region
Honoring a pseudoconversational transaction
Deactivating a workload definition
Updating an active workload definition
Discarding an active transaction from a workload
Updating a workload specification
Using real-time analysis to select a target region for workload balancing
Related reference
WLMSPEC (Workload specifications)
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