Setting service objectives

TSO

TSO is specified in terms of response time. Response time is the elapsed time between the issuance of a command and the system’s response.

For example, a TSO workload might have a response time of less than 1 second for 90 percent of all transactions and less than 3 seconds for 100 percent of all transactions, between the hours of 8:00 A.M. and 5:00 P.M.

See TSO-workload-service-objectives for more information.

Batch

This workload is specified in terms of turnaround time. Turnaround time is the elapsed time between submission of a job and the return of the completed output.

For example, a batch workload might have a turnaround time of less than 5 minutes for 80 percent of batch jobs and less than 10 minutes for 100 percent of all jobs, between the hours of 8:00 A.M. and 2:30 P.M.

See Batch-workloads-service-objectives for more information.

Service class

The service class workload depends on the goal definition and importance that you assign, during WLM service policy definition, to each period composing the service class.

Within the same service class, you can express performance goals for each period in completely different terms. For example, periods 1 and 2 might have response-time goals, while the period 3 goal might be expressed in terms of velocity. Additionally, you can make the period 1 performance goals more important than any other period’s goals.

Service class (continued)

none

1

5

2

4

4

3

8

2

16

1

32

For example, suppose service class TSONORM has three periods defined. Period 1 has an importance of 1, while periods 2 and 3 have no importance rating. Therefore, the performance in period 1 is 32 times more important than the performance in periods 2 and 3. In other words, because period 1 is so much more important to the workload, TSONORM does well as long as period 1 meets its objectives—even if periods 2 and 3 are doing poorly.

Composite

A composite workload is set by assigning a weighting factor to each constituent workload. This factor reflects the workload’s relative importance to the group as a whole. In this way, the different service measures for TSO and batch workloads are synthesized, thus enabling a composite workload to contain a mixture of both workload types. Composite workloads are then measured in terms of the percentage of total service objectives that they accomplish.

See Adding-a-constituent-workload for more information about how composite workload service objectives are measured.

WLM

A WLM workload is a composite of service class workloads. Each constituent workload is equally weighted. For example, if a WLM workload contains service classes TSONORM, TSOHOT, and TSOSHIFT1, the performance of each contributes equally to the WLM workload service objectives as a whole.

Like other composite workloads, the total weight for WLM workloads must equal 100. If the workloads cannot be equally divided into 100, the remainder is distributed among the first few workloads. For example, if a WLM workload has seven workloads, each workload counts for 14 percent of the total service objective with a remainder of 2. In other words, the first two workloads in the WLM workload definition will be incremented by 1 and thus will count for 15 percent instead of 14 percent.