Evaluating Peak Utilization Periods
Once you have identified the peak period, you can look for the bottleneck. Examining ResUsage data is one technique helpful in finding bottlenecks.
Some possible bottlenecks are:
Resource Usage by Priority Scheduler Allocation Group
The ResUsageSps table allows you to see accumulated CPU, number of active processes, and other detail by Priority Scheduler Allocation Group (AG). It carries information that is similar to what is displayed in Priority Scheduler monitor output.
Information carried in the table is organized by:
For those using TASM, each workload definition is the equivalent of one Performance Group in ResUsageSps.
The CpuTime and the IOBlks columns in ResUsageSps are collections of resource usage over the life of this particular logging interval.
No matter what your configuration size, care must be taken to manage what may be an exceptionally high volume of output from ResUsageSps table logging. Plan to offload ResUsageSps data frequently or turn on ResUsageSps logging at only limited times of the day, for example during the times of heaviest usage. To minimize the volume of the output, activate Active Row Filter Mode, when logging is enabled for ResUsageSps.
For ResUsageSps table column definitions, see Resource Usage Macros and Tables.