Dynamic routing with EXEC CICS START TERMID

Use the Web User Interface (WUI) to set up dynamic routing capability for a transaction started with EXEC CICS START, that specifies a terminal ID and a transaction ID, and to use the GOAL algorithm to select the target region.

Note: You should check the system requirements before trying to route EXEC CICS START TERMID dynamically. See CICSPlex SM workload requirements.

In this example, a program running in CICSPA01 begins with EXEC CICS START, which is associated with terminal TRM1, to run transaction PAY1, for which you require a 2-second response time. Terminal TRM1 is associated with region CICSPT01. Transaction PAY1 may execute in any region connected to CICSPT01, that is, in CICSPA01, CICSPA02, or CICSPA03.

This example uses the environment that has already been created as part of earlier examples. You are working in CICSplex PLXPROD1, which comprises TOR CICSPT01 and AORs CICSPA01, CICSPA02, and CICSPA03 in CICS® system group CSGTGTS1. Transaction group TRGPAY03 has transactions PAY1, PAY2, PAY3, and PAY4 associated with it. Workload definition WLDPAY03 was defined to tell CICSPlex® SM that transactions in group TRGPAY03 must be routed to a target region in CICS system group CSGTGS1.

As you want to use the GOAL algorithm, you need to define, in MVS Workload Manager, a Service Class with the required response time and allocate that Service Class to transaction PAY1. For example, you could specify:
  • A Service Class of Fast that has an average response time of 2 seconds.
  • A classification rule that associates Classification Subsystem CICS with transaction ID PAY1 and Service Class Fast.

For more information about Service Classes, see the information about the goal algorithm in Management of the work in a workload.

In CICSPlex SM:
  1. Create a workload specification.
    • From the main menu, click Administration > Workload manager administration > Specifications. This opens the WLM specifications tabular view.

      If the current context is not PLXPROD1, specify PLXPROD1 in the Context field and click Refresh.

    • Click the Create button, and provide the following information:
    • Click Yes to create the specification.
    You must supply:
    • A name for the specification (WLSDYN01 in this example).
    • A Primary search criterion value. USERID is shown in this example, though in fact it doesn't matter whether you specify USERID or LUNAME, because the Primary search criterion value has no effect on simple workload routing. It is used only for some kinds of workload separation, but 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.
    • A Default target scope value, which is the name of the single target region, or group of target regions, to which transactions can be routed.
    • An Algorithm type value. For this example, use GOAL, because the criteria for selecting the target region are based on the requirement that the transaction has a response time of 2 seconds.

    When you click Yes, the WLM specifications tabular view is redisplayed, this time showing an entry for the new workload specification, WLSDYN01.

  2. The next step is to tell CICSPlex SM about the region that's going to be routing the work requests to the target regions in group CSGTGTS1. To associate the workload specification with a routing region:
    • On the WLM specifications tabular view, click the Record check box beside the entry for the WLSDYN01 specification and click the Associate CICS system button.
    • Type WLSDYN01 in the CICS system field and click Yes. The WLM specifications tabular view is redisplayed and you can check that the association between the routing region and the workload specification has been created.
  3. Activate workload routing in the routing region:
    • From the main menu, click Administration > Topology administration > System definitions. This opens the CICS system definitions tabular view.
    • Click the Record check box beside the entry for CICSPT01 and click the Update button.
    • In the Workload manager status field, select YES from the drop-down menu. This change takes effect when CICSPT01 is next started.
  4. Activate workload routing in the target regions.
    • From the main menu, click Administration > Topology administration > System definitions. This opens the CICS system definitions tabular view.
    • Click the Record check box beside the entry for CICSPA01 and click the Update button.
    • In the AOR dynamic routing mode field, select YES from the drop-down menu. This change takes effect when the target region CICSPA01 is next started.

    Repeat this step for target regions CICSPA02 and CICSPA03.

  5. Install program definitions:
    • From the main menu, click Administration > Basic CICS resource administration > Resource definitions > Program definitions. This opens the Program definitions tabular view.
    • Click the Record check box beside the entry for CICSPA01 and click the Update button.
    • Set the Dynamic routing status field to NO from the drop-down box.
    • Click Yes to confirm. The Program definitions tabular view is redisplayed.
    • Click the Record check box beside the entry for CICSPA01 and click the Install button.
    • Type CICSPA01 in the Target scope value field and click Yes to confirm.

    Repeat this step for CICSPA02 and CICSPA03.

  6. Install transaction definitions:
    • From the main menu, click Administration > Basic CICS resource administration > Resource definitions > Transaction definitions. This opens the Transaction definitions tabular view.
    • From the Transaction definitions view, select PAY1 and click the Install button. Type CICSPA01 in the Target scope value field.
    • Click Yes to confirm.

    You can either update the transaction definitions to specify these field values, or you can specify override values when you install the transaction definitions.

In this example task, a program running in CICSPA01, the requesting region, issues an EXEC CICS START command that specifies a transaction ID of PAY1 and a terminal ID TRM1. The START command is function shipped to CICSPT01, the TOR that owns the specified terminal. CICSPT01 acts as the routing region and invokes the dynamic routing exit, which selects the target region. All the AORs in CICS system group CSGTGS1 are possible target regions; the actual target region is selected on the basis of the GOAL criterion of a response time of 2 seconds. CICSPlex SM obtains the Service Class of transaction PAY1 and the identity of the target region to which that Service Class is allocated, from a CICSPlex SM-maintained table.