What function does the new CICSPlex SM Workload Manager (WLM) transaction group (TRANGRP) level algorithm specification provide? What are the implications of the algorithms use? The answers to these questions should help you determine if you want to exploit the transaction group algorithm granularity which is a new feature in CICS Transaction Server for z/OS (CICS TS) V4.2.
Prior to CICS TS V4.2, CICSPlex SM WLM allowed the specification of a single dynamic routing algorithm at the WLM specification (WLMSPEC) level. This had the effect of applying the same dynamic routing algorithm to every routed dynamic transaction in the workload. In addition, if the algorithm needed to be changed within the same workload, then all regions participating in the workload had to be simultaneously closed down to allow the workload to be refreshed with the new algorithm specification.
CICS TS 4.2 now provides the capability to specify an algorithm type at the WLM transaction group (TRANGRP) level, allowing alternate algorithms to be applied to specific transaction codes within the same workload. At the WLMSPEC level, a default algorithm must be specified for the workload. This will be the algorithm that will be applied to all dynamic transaction codes that are not encompassed by a TRANGRP associated with the same workload. The algorithm types (ALGTYPE) that you can specify in the WLMSPEC are:
Any transactions that are required to be evaluated by an alternate algorithm type should be associated to a TRANGRP that identifies the required algorithm type. The options that you can specify for the TRANGRP algorithm type are:
These are the same options as for the WLMSPEC algorithm type, but with the addition of the INHERIT keyword. INHERIT simply means that transaction should use the algorithm type currently associated with the WLMSPEC for the workload. This will be the algorithm type assigned to your existing TRANGRPs when you migrate your CICSPlex SM data repositories up to the CICS TS 4.2 level.
In addition to the provision of this flexibility with regard to relating transaction codes to algorithm types, you can also modify the algorithm type at run time without restarting any regions in the workload using the normal workload definition (WLMDEF) Discard and Install process. There is a one-to-one relationship between an installed WLMDEF and TRANGRP. To modify an installed TRANGRP, you must discard its associated WLMDEF, and then re-install that WLMDEF. This will cause the TRANGRP named by the WLMDEF to be refreshed as well.
CPSM CICSPlex SM CICS/TS CICS TS CICS Transaction Server