CA MICS Hardware and SCP Analyzer (RMF) Queries › WLM Service Class and Report Class Analysis › RMFSRV – z/OS Service Class Analysis by SYSPLEX, CPCID, and SYSID › Uses

Uses

All workloads running on z/OS are assigned to a Service Class, and each Service Class is defined with a level of importance. Most Service Classes are also assigned a goal type (for example, Execution Velocity, Response Time Percentile, and so on) and a performance goal to meet. The z/OS Workload Manager (WLM) manages physical resources (for example, CPU) and uses workload dispatching strategies to meet Service Class goals. Service classes with a higher relative importance value (0 high <--> 5 low) are given preferential treatment.

All three data extracts generated by the RMFSRV query are organized by SYSPLEX, and charts are produced for each Service Class Period. View # 1, CPU and PI show the CPU utilization and Performance Index (PI) for each HOUR. The PI indicates how well the workload performed against the designated goal.

This chart view provides the information required to understand the performance and resource consumption of z/OS workloads. Using this data view, you can monitor the performance of each Service Class Period defined in your WLM Service Policies and Definitions. If a Service Class is routinely exceeding the assigned goal (for example, the PI is consistently 0.8 or lower), or missing the assigned goal (for example, the PI is consistently higher than 1), you can adjust the goal or modify other Service Classes to free up additional resources for the troubled Service Class.

While CPU time is the default resource usage metric plotted, the Data Extract CSV provides a number of other resources usage metrics that can be alternatively selected for charting. These metrics include DASD Service time, paging rates, and average storage used.

View #2, Sampling Summary, allows you to quickly determine whether poorly performing SCPs are being delayed by WLM managed resources, or for other reasons. If you see increased WLM execution delays at times when the SCP goals are missed, you can examine Views #3 and #4 to determine the specific types of execution delays that impacted performance. The resources represented by these delay categories are managed by WLM. The delays experienced by Service Classes can be alleviated by adjusting Service Policy Service Class goals or by adding additional capacity of the resource type indicated.

Note: By design, SYSPLEXES can span Central Processing Complexes. If your SYSPLEXES do not span CPCs, then the first two data extracts are identical, with the exception that the second data extract, Service Class by SYSPLEX CPCID, identifies the CPC in each chart title. If your SYSPLEXES do span CPCs, then the Service Class by SYSPLEX CPCID data extract displays multiple charts for a Service Class that ran on multiple CPCs.