Informix

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  • 1.  Need help about the cpu usage on the function spparse etc.

    Posted Thu May 05, 2022 10:39 AM
    Edited by Portia Melita Fri May 06, 2022 09:39 AM
    I have collected the tprof info on my test box (informix 12.10xc12 aix7.1) and find the function spparse,yield_processor_mvp,sq_cmd,mt_shm_malloc_segid use a lot of cpu  as following:


    Question: how can I optimize the cpu usage ? could I set some parameters to enhance the performance of the ids?

    BTW: I am also think the high CPU usage may be affected by the memory fragmentation . because it use persistent connections .and I have found a lot of waits on sh_lock spin . I try to setting SPINLOCK_BREAKCNT to 200000, but it is not userful . whether there is any way to reduce the memory fragmentation on persistent sessions/connections?
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  • 2.  RE: Need help about the cpu usage on the function spparse etc.

    InnerCircle
    Posted Thu May 05, 2022 11:21 AM

    A lot of connects / disconnects / ad-hoc queries?

    Enabling + tuning statement cache may help, as well as changing application to connect, prepare statement and execute it multiple times. 



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    Vladimir Kolobrodov
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  • 3.  RE: Need help about the cpu usage on the function spparse etc.

    IBM Champion
    Posted Fri May 06, 2022 01:31 AM

    Hi,

    You can go the classic way by matching the needs of your applications/users with the cores provided. So set the correct hyperthreading and cores on the OS side and adjust the Informix server via the number of CPU VPs.
    Then monitor the whole thing on both sides and readjust until everyone is enjoying the performance.


    Have fun
    Henri



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    Henri Cujass
    leolo IT, CTO
    Germany
    IBM Champion 2021 and 2022
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