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  • 30. Re: excessive LOCAL=NO oracle processes
    BillyVerreynne Oracle ACE
    Currently Being Moderated
    I still have an issue with considering 100% as "normal".

    Any gamer will tell you that running any modern FPS will hit the CPU hard and peg it at 100%. And that will be the case from an old CPU to a modern dual core CPU. So 100% on both and everything is fine - no problem? The game could be everything but playable on the older CPU.

    Which begs the question - is 100% optimal use (i.e. is the system coping) or does demand exceed the power of the CPU?

    Glib statements like "this is every day normal stuff" does not cut it - as it implies there is no problem with 100% CPU utilisation.

    Wrong! There could be MAJOR problems with 100% CPU utilisation. Just like there could be major problems with 0% CPU utilisation.
  • 31. Re: excessive LOCAL=NO oracle processes
    ji li Pro
    Currently Being Moderated
    Maybe what needs to be clarified is "for how long of a time are we talking about"?

    If your database is causing 100% CPU utilization most of the time, then I agree that its probably starved for more CPU (please correct me if I am wrong).

    But if your CPU is only at 100% when you run occasional processes that demand the extra processing power, then it should not be an issue, especially if you have multiple CPUs. And on that note, if you are running Oracle on a server with only one CPU that is constantly hitting 100% utilization, then it is time to add more horsepower, more CPUs, and probably other hardware/software resources as well.

    Ji li
  • 32. Re: excessive LOCAL=NO oracle processes
    311441 Employee ACE
    Currently Being Moderated
    Hi Ji

    What if you had a 6 CPU system with CPU utilisation constantly at 100%.

    Would you describe your system as being in an "optimal" state ?

    When someone suggests ""BTW, it's normal to see CPU at 100%, it's designed that way.", how long do you consider it normal before you start thinking actually things may not be that optimal after all ?

    Cheers

    Richard Foote
    http://richardfoote.wordpress.com/
  • 33. Re: excessive LOCAL=NO oracle processes
    ji li Pro
    Currently Being Moderated
    Agreed... but again, I'd still have to ask for "how long?".

    At my last job, I ran 8 dual core CPUs on a clustered Sun V490 rac system with 16 Gb of RAM and occasinally saw our CPU top out (although extremely rare to see all CPUs that busy). I had literally 12,000 to 16,000 simultaneous users connected to the main database using connection pooling (websphere) from a middle tier server. The Websphere constantly kept the CPUs pegged on the middle tier, but that was IBMs software problem, not my databases on my servers.

    (I may be mistaken that I may have only had 4 dual core CPUs per box... can't remember which one had which).

    ji li
  • 34. Re: excessive LOCAL=NO oracle processes
    BillyVerreynne Oracle ACE
    Currently Being Moderated
    One cannot just look at CPU utilisation. And nor does a 50% or 0% utilisation mean "no problem" whereas 100% means "potential problem". Nor does the number of CPUs play the only role.

    A single CPU pegged at 100% can be of major concern on a SMP box with 64 CPUs. As a single process runs on a single CPU - so despite the other 63 CPUs being mostly idle, there can be a performance concern with that single process.

    The utilisation alone is meaningless. And if there has to be a response to the statement "my server shows 100% CPU utilisation", then it is not "This is every day normal stuff". The correct response is "So what!?". It has to be interpreted within the right context.

    That said, a 100% utilisation is more of a potential concern than 50% or 0% utilisation ito a possible CPU bottleneck. And that is an acceptable re-action, much more so than re-acting to 100% utilisation stating this is normal or optimal and to ignore it.

    And that is the basic issue for me - and what believe some posters have tried to raise here.
  • 35. Re: excessive LOCAL=NO oracle processes
    ji li Pro
    Currently Being Moderated
    Agreed... thank you for your clarification.
  • 36. Re: excessive LOCAL=NO oracle processes
    311441 Employee ACE
    Currently Being Moderated
    That said, a 100% utilisation is more of a
    potential concern than 50% or 0% utilisation ito a
    possible CPU bottleneck. And that is an acceptable
    re-action, much more so than re-acting to 100%
    utilisation stating this is normal or optimal and to
    ignore it.

    And that is the basic issue for me - and what believe
    some posters have tried to raise here.
    Hi Billy

    Exactly, well said.

    Of course, "any real-world working DBA would know this . . . . "

    Cheers ;)

    Richard Foote
    http://richardfoote.wordpress.com/
  • 37. Re: excessive LOCAL=NO oracle processes
    ji li Pro
    Currently Being Moderated
    It seems we are all in agreement...

    :-)
  • 38. Re: excessive LOCAL=NO oracle processes
    311441 Employee ACE
    Currently Being Moderated
    Hi Ji

    Not quite.

    I can't agree with anyone who claims "it's normal to see CPU at 100%, it's designed that way" ...

    Cheers ;)

    Richard Foote
    http://richardfoote.wordpress.com/
  • 39. Re: excessive LOCAL=NO oracle processes
    BillyVerreynne Oracle ACE
    Currently Being Moderated
    > Of course, "any real-world working DBA would know this . . . . "

    Yeah.. not sure if I qualify. Just how much should a "real-world working DBA" be able to bench press?
    PS. And my answer to anyone saying what this has to do with being a DBA?: 
        A. Exactly!
    ;-)
  • 40. Re: excessive LOCAL=NO oracle processes
    311441 Employee ACE
    Currently Being Moderated
    Hi Billy

    LOL !!!!

    Cheers

    Richard Foote
    http://richardfoote.wordpress.com/
  • 41. Re: excessive LOCAL=NO oracle processes
    311441 Employee ACE
    Currently Being Moderated
    Hi Don

    Still waiting for my lesson ...

    Based on the report you posted, can you please show me what the "CPU Load" equates to ?

    Can you then please show me what the "CPU utilisation" equates to and how it differs?

    Finally, can you please show me how the CPU in the report is at the "usual" 100% that it's designed to be if this is only meant to be some kinda exception report ?

    Cheers ;)

    Richard Foote
    http://richardfoote.wordpress.com/
  • 42. Re: excessive LOCAL=NO oracle processes
    108476 Journeyer
    Currently Being Moderated
    Still waiting for my lesson ...
    Good luck with that. . . . .

    You insulted me the last time I tried to correct one of your misconceptions, and you were dead wrong, to boot.
  • 43. Re: excessive LOCAL=NO oracle processes
    311441 Employee ACE
    Currently Being Moderated
    Hi Don

    Knew you couldn't ;)

    Cheers

    Richard Foote
    http://richardfoote.wordpress.com/
  • 44. Re: excessive LOCAL=NO oracle processes
    108476 Journeyer
    Currently Being Moderated
    Knew you couldn't ;)
    Yup, nobody can teach someone who is not willing to listen and learn . . . .

    You just want to argue . . .
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