Example: Defining a system rule for a high water mark of active tasks in your CICS regions

This example shows you how to define a typical policy system rule using the CICS Explorer® Policy Definition editor. In this example, you want to define a system rule that will emit a message when the number of active tasks in your CICS® regions goes above 90% of your MXT value.

Procedure

  1. Create a CICS bundle project called CICS_system_rules. All policies are defined in a CICS bundle project using CICS Explorer. For details of how to create a CICS bundle project, see Creating a CICS bundle project.
  2. After you have created a CICS bundle project, right-click the bundle project in the Project Explorer view of CICS Explorer and select New > Policy Definition to open the Policy Definition editor as follows:
    Figure 1. Create Policy Definition tab
    This figure shows the Create Policy Definition tab in the Policy Definition editor.

    Enter a name for the policy in the File name field and click Finish. This opens the Policy Overview tab of the Policy Definition editor.

  3. On the Policy Overview tab, you can optionally supply a description for the policy rules.
    Figure 2. Policy Overview tab
    This figure shows the Policy Overview tab in the Policy Definition editor.
  4. Define the policy rule to issue a message when the number of tasks in the CICS region goes above 90% of the MXT value.
    1. On the Overview tab, click the New button to the right to open the New Rule dialog as follows:
      Figure 3. New Rule dialog
      This figure shows the New Rule dialog in the Policy Definition editor.
      Define the new rule as follows:
      Field Value
      Name goes_above_90_percent_of_MXT
      Description (optional) Issue a CICS message when the number of active user tasks goes above 90% of MXT
      Rule type User tasks
    2. In the Conditions section of the Rules tab, define the condition that will trigger the automated action.
      Figure 4. Rules tab
      This figure shows the Rules tab in the Policy Definition editor.
      Only one condition is available for this rule type: Percentage of MXT. Define it as follows:
      • Select Goes higher than from the first drop-down box.
      • Select 90% from the second drop-down box.
    3. In the Action section of the Rules tab, define the action to be taken when the rule is triggered.

      The action defaults to Issue a message and can be used as-is. That completes the definition of the required system rule to issue a message when the number of active task in a CICS region goes above 90% of the MXT value.

      You can also specify other actions such as emitting an event and changing the z/OS® WLM open status. For instructions, see Step 7 in Creating a policy in a CICS bundle project.

That’s it! With the equivalent system event, you have to choose which data to capture in the emitted event from a list that includes the from task count, the to task count the MXT value and the threshold defined. Whereas a policy system rule is much simpler to use because the events are pre-configured to contain all this information in the emitted events.

What to do next

To deploy this policy to a CICS region, you need to first export the CICS bundle project to zFS and then define, install and enable a CICS BUNDLE resource which refers to it. For details of how to do this, see Creating a policy in a CICS bundle project. Once that’s done, whenever the number of active tasks in your CICS region goes above 90% of MXT, the following CICS message will be sent to the CMPO destination which by default is re-directed to CSSL.

DFHMP3009 07/05/2020 11:39:27 IYK2Z3B1 Task 00252 (STRT) has triggered a taskThreshold system rule 
goes_above_90_percent_of_MXT FROM=90, TO=91) defined by policy mySystemRules in bundle CICSDEV_system_rule.

In this case, the CICS region has the MXT value set to 100 so the policy triggers when the 91st task is attached.