You know you need to reduce software costs wherever possible. Fine tuning of your batch can do this for you. IBM may recommend using a single LPAR group (Group Capacity soft cap limit) for all LPARS on a CPC, but this implementation might not work for you on every CPC. You might have LPARs with products or applications that differ a great deal in CPU hourly usage rates from other LPARs.
Certain LPARs may drive the cost because of their CPU-intensity. In other cases, you might want to eliminate soft capping on LPARs with very stringent service levels. What you really want is to have all the control possible to ensure you strike the right balance between cost savings and performance.
The Automated Capacity Management (ACM) capability of Compuware ThruPut Manager can help you better strike that balance. ACM automates the process, and it does so whether you have soft caps in place or not. While WLM does a good job of managing performance, its primary goal is not to control costs. WLM has one small function in this area and that is to inform PR/SM when the R4HA has exceeded the soft cap limit. PR/SM then caps the LPAR(s) until the R4HA is back below the limit. The technique is somewhat blunt and indiscriminate with respect to business priorities.
ACM tracks and responds to numerous variables. It can respond in both a gradual and granular fashion to control the R4HA by constraining the workloads you specify. And it does this only when and to the degree that you specify. You need not choose between running totally unconstrained and slamming the door when the R4HA hits the wall. ACM also detects when demand decreases and when it is safe to resume constrained work.
When you have some LPARs running only z/OS, two running CICS and DB2 and one running CICS, DB2 and IMS, you may want a vehicle to organize the LPARs so that ThruPut Manager can be more precise in controlling cost. To make this fine tuning possible, the new concept of LPAR Sets was created in ACM, available in the latest version seven release of ThruPut Manager. We’ll talk more about LPAR Sets in the next ThruPut Manager post.