The ENF 57 and ENF 41 listener exits

When the WLM scheduling environment integration is active (the value of OPCOPTS SECHECK is not set to NO for all trackers), by default each tracker activates its own ENF 57 and ENF 41 listener exits. Therefore, for each image, a pair of these exits are at work.

The ENF 41 exit (EQQZNF41) sends an event every time a change in the WLM policy occurs, so that the controller is informed that a change in scheduling environment availability or definition have taken place. As a consequence, the controller resubmit all the operations in READY, WAITING FOR SE status that belong to the Sysplex where the WLM policy change occurred.

The ENF 57 exit (EQQZNF57) sends an event every time a scheduling environment becomes available, so that the controller is immediately notified that it can submit a pending job (in READY, WAITING FOR SE status) again. This means that, for example, if you have 32 MVS™ images, when scheduling environment SEDB2 becomes active, the HCL Workload Automation for Z controller is sent 32 events containing the same information. If you have many scheduling environments that change their status often, the performance of your system might be affected, depending also on the size of the workload on the controller.

To avoid unnecessary processing, you can suppress the activation of exits ENF 57 and ENF 41 on specific trackers, if this is compatible with your configuration. Considering that the tracker is in the same MVS™ image as the controller (either in the same or in a separate address space), in a Sysplex hosting both the controller and trackers you can use the SUPPRESSENF parameter to reduce the number of exits to the ones running on the controller. Proceed as follows:
  1. Activate the exit on the controller: the value of OPCOPTS SECHECK must not be set to NO.
  2. Activate the exit on all the trackers that are not located in the same Sysplex where the controller is: on each tracker the value of OPCOPTS SECHECK must not be NO.
  3. Suppress the exit on all the trackers located in the same Sysplex where the controller is: on each tracker the value of OPCOPTS SECHECK must not be set to NO and SUPPRESSENF must be set to YES.