Db2 Tools

  • 1.  How to reduce CA DB2 performance tools CPU consumption?

    Posted Aug 22, 2017 09:32 AM

    Hi community members.
    We use CA DB2 Detector and DB2 Subsystem analyzer V19.
    We would like to reduce these products CPU consumption.
    For Detector we defined we defined USEZIIP = Y
    For SSA Volume and Extent = N and Sampling Rate = 25%
    Are there some other options?
    Is it possible to measure CPU consumption of these monitors’ collection processes outside of Xmanager?



  • 2.  Re: How to reduce CA DB2 performance tools CPU consumption?
    Best Answer

    Posted Aug 22, 2017 05:24 PM

    Eugene,

     

    Thanks for the query. 

     

    For reducing Detector overhead, the main new feature is Collection Tasks feature described in the doc.

    https://docops.ca.com/ca-detector-for-db2-for-z-os/19-0/en/product-information/enhancements#Enhancements-collection_processRedesignedSQLCollectionProcess 

    While the USEZIIP parm is wanted, you also need the parm USECOLLTASKS=Y

     

    Take a look at the collection stats for each interval so you can see how much zIIP offload you are getting plus the usage of the Collection Task queues. 

    https://docops.ca.com/ca-detector-for-db2-for-z-os/19-0/en/using/collecting-sql-data/view-collection-status 

    You can find out if your zIIP processors are being used or if they are too busy and you are getting zIIP on CP values.


    For Subsystem Analyzer, depend SSA Volume and Extent = N and Sampling Rate = 25%

    https://docops.ca.com/ca-subsystem-analyzer-for-db2-for-z-os/19-0/en/using/collecting-data/reducing-collection-overhead 

    If your GETPAGE activity for an object is 300,000 or more, then use the 3% parm value.   At 25%, you are accurate with object at 30,000 Getpages.


    The best way to measure overhead of any monitor is run a workload without the monitoring and run the same workload with the monitor. 

     

    Let us know if you have further questions,

     

    Jeff Gross

    Product Owner



  • 3.  Re: How to reduce CA DB2 performance tools CPU consumption?

    Posted Aug 27, 2017 04:44 AM

    Hi Jeff,
    Thanks for you input. The performance data of CA Detector V19 is OK. However for Subsystem Analyzer the workload overhead is so significant, that we are forced to stop its collection during peak loads period. Changing sampling rate does not really help.



  • 4.  Re: How to reduce CA DB2 performance tools CPU consumption?

    Posted Aug 28, 2017 09:13 AM

    Eugene,

     

    Thanks for the feedback.  Just to clarify, did you try the 3% Sampling Rate?  I would like to learn more about your situation and would be happy to chat offline so I can learn from your experience.   Feel free to Email me at Jeff.Gross at ca.com

     

    Jeff