service class assignment requirements

Document ID : KB000044440
Last Modified Date : 14/02/2018
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Question:

What is the service class assignment required for the
PC task and VTAM UI task? higher or same as db2 tasks or doesn't matter?
For Sysview-Performance Management Option-for DB2

 

 

Answer:

The PC and VTAM UI tasks are not high activity tasks and so do not require a specifically high dispatching priority.

It is the Data collector task where the high work load happens and so it's z/OS dispatching priority is important.


The dispatching priority specified for the data collector (assigned in z/OS Performance Group parameters)
must be set higher than DB2 or any connections to DB2 for CA SYSVIEW for DB2 to collect accurate data.
We recommend the following dispatch priority (from highest to lowest):
IRLM
CA SYSVIEW for DB2 data collector
DB2 address spaces and associated connections The data collector should have a higher priority than
DB2 to prevent the data collector from being swapped out while DB2 is active. If this were to happen,
DB2 trace records could be lost.


So it would not cause a problem if the PC and VTAM UI tasks had the same service class assignment as DB2.