The Workload Manager features can be used to ensure more consistent
response times for users. For example, you might need to meet a specific
Service Level Agreement (SLA) with users, minimize performance
complaints, or facilitate capacity planning. The grouping of processes
into workgroups gives the system manager the ability to partition the
system into groups with similar needs. Altering the scheduling
characteristics of those workgroups provides the control over CPU
access, which in turn helps determine response time.
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 | CAUTION: It is critical to understand that CPU access is just one component of
response time. The Workload Manager can help handle this aspect,
but cannot handle problems with disk access speeds, memory constraints,
network latency and availability, or the other components of response time. |
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In controlling CPU access, you can either control the workgroup needing
the consistent response times, or identify the other workgroup(s) whose
behavior leads to inconsistent response times and control those workgroups.
To control a single workgroup |
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In handling a single workgroup, you can change the base and limit priorities,
change the rate of priority decay (by adjusting the quantum), or assign CPU
minimum and/or maximum percentages. Which control is most effective
depends on the characteristics of the processes you want to control. It may be
the case that placing the workgroup at priorities 160-170 gives consistent
1-second response time to those users. Alternatively, you may need to set
a minimum CPU percentage of 20% to the workgroup in order to ensure
1-second response time.
To control other workgroups |
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If processes in one workgroup (workgroup_1) are experiencing
inconsistent response times, it may be due to the influences of another
workgroup (workgroup_2). For example, workgroup_2
may be set to a higher priority and contain processes
that perform long transactions, leading to increased response times for
the processes in workgroup_1. To handle the situation, you can:
Move the processes in workgroup_2 that perform long transactions
to a lower-priority workgroup.
Move the entire workgroup (workgroup_2) to a lower priority.
set a CPU maximum for workgroup_2, restricting the amount of CPU
it can consume.
If it is a single process that is disrupting the response times of others,
move it to a lower-priority workgroup.
