HP-UX Workload Manager User's Guide

Introduction
Why use Workload Manager?
Chapter 148
page 135. Information about configuring WLM to manage resources and
application performance across partitions is provided in Chapter 7,
“Managing SLOs across partitions,” on page 255.
Service-level objectives (SLOs)
A key reason for using WLM is its ability to manage service-level
objectives. After defining a workload, you can specify one or more SLOs
for each workload. WLM allocates CPU resources to workloads based on
whether the application in the workload is underperforming, meeting, or
overperforming its SLOs.
SLOs can be shares-based or goal-based. With a shares-based SLO, WLM
tries to grant the associated workload a fixed amount of the CPU
resources by allocating CPU shares for the workload. (Each CPU share is
1/100 of a single core or 1/100 of total cores on a system, depending on
the WLM mode of operation, as explained in “Using absolute CPU units”
on page 217.)
With a goal-based SLO, WLM actively changes the CPU allocation of the
associated workload to best meet the SLO. Goal-based SLOs are based on
one of two types of goals:
•Usage Goals
Goals based on a workload’s utilization of its allocated CPU
resources. If the processes in a workload are not using a certain
amount of the workload’s allocation, the allocation is decreased; if
the processes are using a high percentage of the workload’s
allocation, the allocation is increased.
• Metric goals
Goals based on a metric, such as processing at least x transactions
per minute or a response time under y seconds. Metric goals are
based on performance data and require understanding of that data.
HP recommends using usage goals, as usage goals can be
implemented immediately without prior knowledge of workload
performance.
A goal-based SLO consists of:
•A workload
•A goal
• A priority ranking