SYSVIEW Performance Management

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  • 1.  information about CSYSDMON/TASK_GSVCTPPT

    Posted Jul 07, 2020 07:37 PM
    Hello Colleagues.

    When we are reviewing other information on the CSYSDMON Global screen, we notice the values ​​in TASK_GSVCTPPT, the values ​​shown here in the count are very high compared to the other counts. please can you help me understand  why this value is so high ...
    This occurs in all CICS regions.
    Here is an example.

    Many thanks!

    Fernando

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    IT Mainframe Specialist
    IBM de Chile
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  • 2.  RE: information about CSYSDMON/TASK_GSVCTPPT

    Broadcom Employee
    Posted Jul 08, 2020 06:44 AM
    CICS Transaction Post Processing Task

    The subtask GSVCTPPT will be started within each CICS region to perform transaction post processing functions.

    The SYSVIEW task GSVCTPPT will perform the following functions at transaction completion:

    • Create detailed transaction record
    • Threshold processing
    • Statistics summaries 
    The above work is performed asynchronously to other CICS tasks. The work is performed at task end and trigger by the CICS global user exit XMNOUT.

    By moving the work to a separate task, the global user exit XMNOUT will complete more quickly, returning control back to CICS. This will increase CICS transaction throughput. The work will be performed in parallel to other CICS activity.

    A very high percentage of the work performed by the GSVCTPPT subtask is eligible to run on zIIP processors. In any case the zIIP eligible percentage will exceed 98%.

    Work is queued to the GSVCTPPT for processing. Each time the GSVCTPPT processes the queue, one or more task end events will be processed. It is not necessarily a one-to-one task match.

    The SYSVIEW command CSYSDMON will display statistical information about our processes and CPU usage information include zIIP information.

    In the sample CSYSDMON provided, you will see the count for the TASK-GSVCTPPT is 39,050,320. This means that the task processed at a minimum 39,050,320 task end events. Each time the task processes the queue, one or more task ends are processed.

    The corresponding CPU time for the task is: 00:28:59.  This means on average the tasks uses 0.000044 CPU time ( 44 microseconds) each time the task processes the queue. The CPTime field on your example shows that only 0.000162 CPU seconds we used on a general CP. This means that virtually all CPU used was on a zIIP processor. Running on a ZIIP processor results in a much lower cost. Additionally, zIIP processors run at full speed compared to general CPs if running a sub-capacity machine. 

    Your example screen display shows the first 80 columns of the display. Many more fields are available by scrolling to the right.

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    Todd J. Gagle
    Architect of Software Engineering, Team SYSVIEW
    Broadcom
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