2. PERFORMANCE REPORTING ANALYSIS › 2.7 Graphic Analysis › 2.7.5 Paging Graphs › 2.7.5.6 Demand Page Rates by Workload Type-Pie Chart

2.7.5.6 Demand Page Rates by Workload Type-Pie Chart

GRAPHIC RESULTS

This graphic analysis provides a pie chart of demand page
rates and relative shares belonging to user defined workload
types.  Each defined workload for which there is data is
shown as a separate slice.

ANALYSIS GUIDELINES

If demand paging exists, this chart will show which workloads
are experiencing the page faults.

Additional information can be obtained by looking at paging
response times.  The I/O response time multiplied by the
number of page faults per second per workload type show the
impact this paging is having on each workload type.  Dividing
this number by the average MVS multiprogramming level for a
workload would give you an estimate of the effect that an
individual user or job would experience.

Workloads that offer transaction reporting can provide
additional insight into the impact of paging, particularly
slow paging, upon these workloads.  The portion of the
transaction response time caused by paging could be estimated
by calculating the number of demand pages per transaction and
multiplying the result by the paging response time.

The detailed behavior of the paging subsystem can be further
analyzed using the Auxiliary Storage Management analysis
reports described in Section 2.3.

SPECIAL CONSIDERATIONS

If you do not provide a workload description, as shown in
Section 2.7.6.3, each performance group or service class will
be treated as a separate workload.  This may provide so many
unique categories that SAS/GRAPH will shift from using a pie
chart to using a horizontal bar chart.  While a horizontal
bar chart prevents the loss of information from the chart,
you will probably find analysis and reporting more meaningful
if you describe workloads.

A further consideration is that if you choose to use report
performance groups (rather than control groups), or report
service classes (rather than standard classes), overlapping
resource utilization of such groups or classes will tend to
overstate actual utilization, and should only be done with a
full understanding of the impact on the resulting analysis.