HP-UX Workload Manager User's Guide

Configuring WLM
Defining SLOs
Chapter 5 203
Goals vs stretch goals
You can specify one or more goals for a single workload. The highest
priority goal should represent the minimum acceptable service level. All
other goals should indicate stretch goals—goals that may be hard to
achieve, but are desired if possible. Assign stretch goals lower priorities
than the primary goal.
Think of goals as “needs” and stretch goals as “wants”. Needs (goals) are
required to complete the task at the desired performance level.
Wants (stretch goals) form a superset of the needs and may increase
performance, but only at the sacrifice of the needs of other services.
Consider this trade-off when assigning priorities to your goals and
stretch goals.
The following example shows a goal at priority 1 with a desired response
time of less than 2.0. The stretch goal, with a priority of 5, is for the
response time to be less than 1.0. This stretch goal may be met, but only
when the CPU resource requests of all SLOs at higher priorities are
being met.
# This is an SLO for the finance group.
slo finance_query {
pri = 1;
mincpu = 20;
maxcpu = 50;
entity = PRM group finance;
goal = metric fin_app.query.resp_time < 2.0;
condition = Mon - Fri;
}
# This is a stretch goal for the finance group. If all other
# goals of higher priority have been met, apply more CPU to group
# finance, so its application runs faster.
slo finance_query_stretch {
pri = 5;
mincpu = 20;
maxcpu = 80;
entity = PRM group finance;
goal = metric fin_app.query.resp_time < 1.0;
condition = Mon - Fri;
}