Runaway tasks can consume all available CPU if both/either DRAS and CCITCP tasks run with low priority (Service Class), they get no resources and cannot process.
What Workload Manager Service Class/Dispatching Priority should be used for DRAS and CCI?
Set the service class for DRAS as high as allowable (high) and CCITCP as high as JES or SYSSTC.
The CA DRAS task can be executed as a started task or a batch job. Depending on site-specific requirements, it is recommended that it be defined as a started task to ensure a higher dispatching priority and greater throughput. To run CA DRAS as a started task, the STC JCL must be copied into a system PROCLIB.
Note: Use the REGION=0M parameter in the JCL on the Job Card statement for the task, to allocate the maximum system default size.
Set the dispatching priority for the tasks CCITCP, CCITCPGW, CCISSL, CCISSLGW, and CCILGR. These tasks all service multiple applications and tasks. Their dispatching priorities must be greater than or equal to the highest dispatching priority of any task requesting their services.
CCI Support recommends:
Run ENF and any CCI tasks in a service class close to or equal to JES. Generally this is SYSSTC but can be whatever the customer has defined. The purpose is to ensure it gets appropriate cpu cycles to handle work on behalf of other CA applications.