HP-UX Workload Manager User's Guide

Configuring WLM
Defining SLOs
Chapter 5200
You cannot specify both a goal statement and a cpushares statement in
the same SLO. Similarly, you cannot have a workload with one SLO that
has a goal statement and another SLO that has a cpushares statement
that includes more.
Specify the goal of an SLO using the following syntax:
goal = goal_expression;
where
goal_expression
Indicates either a usage goal or a metric goal
(performance goal). Use a usage goal to ensure a
workload uses a certain percentage of its allocated
CPU resources. Usage goals are especially beneficial
when you have a workload that cannot provide
performance data. Metric goals are based on
performance data and require understanding of that
data. Because you can implement usage goals
immediately without prior knowledge of workload
performance, HP recommends using them instead of
metric goals.
With a usage goal, WLM adjusts a workload’s allocation to more
efficiently match the workload’s actual CPU usage. For example, if a
workload is using 20 CPU shares and has a 50-share allocation, its
utilization is 20/50 or 40%. WLM attempts to keep a workload’s
utilization between a low and high bound. WLM tracks the usage metric
internally, on a workload-group basis; you do not have to provide it.
NOTE Typically, you should set wlm_interval to 5 when your WLM
configuration contains a usage goal.
For details about specifying metric goals, see “Specifying a metric goal
(optional)” on page 470. Specify a usage goal in an slo structure as
follows:
goal = usage _CPU [low_util_bound [high_util_bound]];
where
low_util_bound