Coding Each AOF Rule Type › Global Variable Rules › Execution Considerations for GLV Rules

Execution Considerations for GLV Rules

The processing section of a rule that responds to a GLV event executes in the address space from which the global variable event originated. Therefore, any type of logic that could possibly suspend the processing of a GLV rule should be performed by scheduling an OPS/REXX program to a CA OPS/MVS OSF TSO, TSL, or TSP server, as described in the chapter “Code and Debug AOF Rules.”

A change in the value of an OPS/REXX global variable triggers a GLV rule. However, a global variable event does not trigger a global variable rule under these conditions:

• Changing the value of a global variable triggers a global variable event unless that variable has a stem of GLOBALx. or GLVTEMPx. (where x is a number from 0 to 9)
• During CA OPS/MVS startup or shutdown
• When a global variable in the initialization or termination section of the rule changes
• When a global variable is deleted

If a global variable update occurs in the processing section of a rule, the rule can trigger itself. A global variable rule triggering itself is not true recursion. The AOF maintains such global variable events in a FIFO queue. The AOF extracts the events from the queue and triggers other rules when the rule that caused the recursion has finished executing. The GLVPENDINGMAX parameter determines size of the FIFO queue; the default queue size is 100.

To prevent infinite recursion, specify the GLVCHAINMAX parameter to limit the number of global variable events that can occur from in the original rule; the default limit is 1000 events.

Note: For more information about the GLVPENDINGMAX and GLVCHAINMAX parameters, see the Parameter Reference.