HP-UX Workload Manager User's Guide

How WLM manages workloads
Example of WLM in use
Chapter 3124
Example of WLM in use
Consider a server that runs two workloads:
• Accounts payable
• Accounts receivable
The accounts payable and accounts receivable workloads run constantly.
Without WLM, the performance of these workloads varies greatly
throughout the day, based mainly on the amount of work competing
workloads have at any given time. Consequently, the server might be
overloaded with accounts payable processing, greatly slowing the
accounts receivable processing. Figure 3-3 illustrates this scenario.
Figure 3-3 Server without WLM
By using WLM, you can define SLOs for the workloads to specify their
desired performance levels. For example, the accounts payable workload
can be assigned a goal of paying out money in less than 2.5 seconds,
while the accounts receivable workload is assigned a goal of depositing
the incoming money in less than 1 second. WLM uses data from data
collectors to determine how much a workload is underachieving or
overachieving its desired performance level. WLM then automatically
adjusts the CPU allocation, based on priorities, for workloads that are
underachieving or overachieving. Figure 3-4 shows how the workloads
are controlled under WLM.
Number of transactions
Accounts payable (AP)
Accounts receivable (AR)
4
3
2
1
Response time in seconds