Task kill limitations and considerations
The task kill function gets control at two CICS global exit points: XEIIN and XRMIOUT. The task has to issue an EXEC CICS or return after an RMI call in order for the task kill function to get control and check the thresholds that are specified in CMRTTHR. Because of this limitation, a task might not be killed at the time the threshold is exceeded; it will be killed the next time the kill exit gets control and checks the kill thresholds.
The programs that provide the task kill function are subject to discard and create processing that is employed by the TERM and INIT functions for auto maintenance. The task kill function is turned off (if it is on) when a TERM function is issued and restarted when the INIT function is issued.
The file call threshold includes remote files if the extractor is active. If the extractor is not active and MN=ON, the kill exit counts only local file access because it uses the CICS task monitoring area (TMA) field, which is not updated for remote file access.
When the extractor is active and TSQ and TDQ monitoring are active, the threshold includes local and remote access; otherwise, when only the extractor is active, only local access is included.
The Task Kill Exit is not supported in a CPSM CMAS or WUI region. Attempts to start the Task Kill Exit will not be processed.
The Option Warn and Warning Thresh functions are mutually exclusive. The kill thresholds are always used in WARN-only mode.
MainView for CICS uses the warning thresholds only when the option Warning Thresh is set to YES. In addition, it is used only when you also specify a kill threshold for the resource.
When you set the Warning Thresh to YES, when a warning threshold for a resource is exceeded, MainView for CICS uses the kill threshold of the same resource the next time it gets control.
This means before a task is killed by the exit it might have multiple warning messages such as one for each monitored resource or just one warning message for the resource that has exceeded the Kill threshold.
There is also a possibility MainView for CICS kills the task at the next CICS EXEC right after issuing a warning for the resource (depending on the value of the resource).
It could also delay killing a task depending on when the exit gets control. The exit does not get control until the task schedules an EXEC CICS.
The resource might exceed both warning and kill thresholds before the exit gets control but the warning threshold is checked first and the kill threshold is not checked until the next EXEC CICS, therefore delaying the kill.