Suppose you have the following STC classification rules to classify the CICS® regions:
Subsystem Type . : STC Fold qualifier names? Y (Y or N)
Description . . . IBM-defined subsystem type
-------Qualifier--------- -------Class------ Storage Manage Region
Action Type Name Start Service Report Critical Using Goals Of:
____ 1 TN TOR ___ VEL80I1 ______ NO TRANSACTION
____ 1 TN AOR* ___ VEL60I2 ______ NO TRANSACTION
In this scenario, assume that the CICS regions adhere to a Work Manager/Consumer model. This means that the TOR acts as a work receiver of requests from the work originator and as a sender of results back to the work originator. The TOR just distributes the work to consumer processes in the AORs which start application programs to perform the function behind the work requests.
The TOR typically only requires short access to resources, but it also needs very fast access in order to avoid being a bottleneck. The AORs typically run more resource intensive programs which do not require the same fast access to the resources.
In this setup, when contention increases on the system, WLM has no way to give faster access to TORs than to AORs, if no other workload like batch work with lower service goals exists that can be demoted. At higher utilization levels, typically above 85%, a noticeable queue delay within the TORs can be recognized. This reduces the end-to-end response times of the CICS transactions and the throughput of the CICS work.
Subsystem Type . : STC Fold qualifier names? Y (Y or N)
Description . . . IBM-defined subsystem type
-------Qualifier--------- -------Class------ Storage Manage Region
Action Type Name Start Service Report Critical Using Goals Of:
____ 1 TN TOR ___ VEL80I1 ______ NO REGION
____ 1 TN AOR* ___ VEL60I2 ______ NO REGION
The negative effect of this solution is that CICS transaction statistics are no longer available for managing the CICS work and only through classes for reporting purposes. This workaround in fact reduces WLM's capabilities to a reporting only function for CICS.
Subsystem Type . : STC Fold qualifier names? Y (Y or N)
Description . . . IBM-defined subsystem type
-------Qualifier--------- -------Class------ Storage Manage Region
Action Type Name Start Service Report Critical Using Goals Of:
____ 1 TN TOR ___ VEL80I1 ______ NO BOTH
____ 1 TN AOR* ___ VEL60I2 ______ NO TRANSACTION
This option allows WLM to manage a region by the goals of the regions but also ensures that the region tracks all transaction completions correctly so that WLM can still manage the CICS service classes with response time goals. The new option should only be used for CICS TORs. All AORs should remain at the default (TRANSACTION). In addition, the service class for the CICS TORs should be defined with a higher importance than the service classes for the CICS transactions.
The result is that the CICS TORs now can access the resources they need as fast as possible. Because TORs consume typically only between 5 to 10% of the total CICS resource consumption the goals of the CICS service classes still manage the important parts of the CICS workloads and ensure that work is managed towards response times.