How to Control Your CPU Demand and Costs at the Job Level
Batch jobs can sometimes surprise you with CPU demand, which could cause you problems with other workloads. MVS doesn’t give you a way to control total CPU demand. You can set guidelines for steps, but not for the whole job. Unpredictable runtimes put a burden on initiator deployment.
Compuware ThruPut Manager, which automatically and intelligently optimizes the processing of batch jobs, can give you the ability to better control CPU demand with its CPU Capping and CPU Normalization functions. Learn more when you read our white paper “Automated Capacity Management (ACM): ThruPut Manager and Soft Capping.”
CPU Capping allows you to set a specific CPU job limit for a given job or a given type of job. You use the JAL action statement SET with keyword CPUCAP. Using SET CPUCAP (0:30) sets a 30-second limit on the job. This limit-value will be inserted into the job prior to the exit for job initiation. Now you can really set some expectations, which helps you manage the whole batch cycle.
You can also use the CPU Normalization service in conjunction with CPU Capping. This is particularly useful when you have different processor types in your complex. CPU Normalization adjusts the CPU limits based on the CPU speed of the given processor. For this, you would use SET NORMALIZE(YES).
ThruPut Manager gets the normalization factors from the JES2 TMPARM statement with the keyword FACTORn. You can create up to eight sets of FACTORS, which will be used when you use the SET NORMALIZE JAL statement. These are numbers to be multiplied with the JOB and STEP CPU time. You will have to specify these factors with the TMPARM statement:
FACTOR1=(2.5 PRD1),(1 PRD2),(3 PRD3)
FACTOR2=(1.5PRD1),(1 PRD2),(1.1 PRD3)
The first digit is the normalization value. The second is the SMFid. Before the job initiates, but after the CPU limit is applied, the CPU times are multiplied by the factors in the TMPARM. If you have more than one FACTOR set, you simply specify which one you would use in JAL. For this, you would use SET NORMALIZE(YES) FACTOR(2).
And that’s it—now you can have much more granular control of your jobs. Read “Automated Capacity Management (ACM): ThruPut Manager and Soft Capping” to learn more.
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