Using RMF

Ring performance is only one aspect of total system performance. Focus your monitoring efforts on total system performance and look more closely at ring performance only when it appears to be affecting how well your system meets your overall performance objectives.

RMF™ Monitor I session reports are particularly useful in determining how ring performance affects overall system performance. One key report is Workload Activity. Use this report to determine the resources (processor, I/O, and storage) that global resource serialization is using. To obtain the clearest picture of resource consumption, place global resource serialization in its own performance group or report performance group.

RMF Monitor II session reports can also provide information about how global resource serialization affects the system. For example, you can use the Address Space State Data report to determine how much processor time global resource serialization consumes and the number of page faults the GRS address space experiences. To provide the optimum response time, the page-in rate for the GRS address space should be close to zero.

RMF Monitor III (workload delay monitor) reports can also help you deal with problems related to delays of jobs or users. These reports can show address spaces delayed and whether resource contention is contributing to the delay, as well as the jobs affected. They can point out jobs that are being slowed by ENQ delays. If the reports indicate ENQ delays, possible reasons might be:

A job is delayed because the system is waiting for the RSA-message to complete its cycle. Lowering the RESMIL value might resolve the problem.
A job is delayed because the RSA-message is encountering a communication delay. Ensure that the links used to send the RSA-message are not installed on the same channels as devices that monopolize the channel for long periods of time.
A job is delayed because there is contention for the resource; another job is using it. If the delay is caused by a reserve, investigate the possibility of converting the reserve to reduce contention for the resource.

The Monitor I Enqueue Contention Activity report can also help you to identify the resources that are causing the most significant contention delays.