"What are the MainView for z/OS Diagnostic views, and how would I use them to debug performance or high CPU usage problems?"

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    MainView for z/OS


    MainView for z/OS



    MainView for z/OS 3.1.00
    MainView for z/OS 3.0.00
    CMF Monitor 5.9.00
    CMF Monitor 5.8.00


    "What are the MainView for z/OS Diagnostic views, and how would I use them to debug performance or high CPU usage problems?"







    Legacy ID:KA399788


    The following MainView for z/OS diagnostic views can be helpful in identifying the cause of performance or high cpu usage problems. These views are mainly intended for use by BMC Customer Support.

    DCSTAT - Shows the status of the MainView for z/OS data collectors.

    DCPERF - This is a tabular view that shows the CPU usage of each Data Collector. This view can help determine if there is a particular data Collector that is causing a problem.

    CMF Monitor includes two new views from version 5.9 onwards to provide similar information on the CMF Samplers:
    SAMPERF - Displays the CPU utilization of the MainView for z/OS PAS samplers, in decreasing order of CPU usage.
    SAMSTAT - Displays the address of CMF's sampler csects and service level (intended for use by BMC Customer Support).

    "JTCB pasname" - Shows the resource usage of each TCB within the MainView Product Address Space (PAS). Along with PASSTAT and DCPERF, this can be helpful to determine where the time is being spent in the PAS.

    PASSTAT - Provides overall MainView for z/OS PAS CPU usage within the major functions of the PAS. This is often useful in determining the problem area when high cpu usage is reported. Using this view it is possible to get an idea of whether the cpu usage may be due to the data collectors or the data selectors (i.e., displaying the data)

    In addition to the MainView for z/OS views, the following view provides useful information when used in conjunction with the above views:
    DIAGUTAS - This is a MainView Infrastructure view that shows the status of any current User sessions communicating with the MainView PAS. If a user session is repeatedly requesting data, it will show up here and may be an indication of excessive data retrieval (ASU mode for 3270 screens, MainView Explorer sessions or alarms in MainView Alarm Manager)

    When sending these views to BMC Customer support please provide EXPORTed screen captures to ensure all columns/rows are included.
    As an example, Issue EXPORT from the primary command line of PASSTAT view. Set the Export output data set LRECL(Record Length) to 256. Then download the exported PASSTAT view to PC text file and either send in via email or attach via the web.

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    3. MainView for z/OS


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