DBAsupport.com Forums - Powered by vBulletin
Results 1 to 10 of 10

Thread: CPU at 100%

  1. #1
    Join Date
    Jan 2001
    Posts
    515

    CPU at 100%

    I have a question about resource utilization. We have an AIX server with many different Oracle 10G databases on it. Recently we had issues because a process chewed up 100% of the CPU.

    I know that I can use Resource Manager to limit resource allocation per database , but how that work when you have many different databases fighting for the same CPU? Even if each database had a resource plan wouldn't it still have issues because of the number of databases?

    Thanks

  2. #2
    Join Date
    Aug 2007
    Location
    Cyberjaya,kuala lumpur
    Posts
    340
    how many database have in your server ?
    which process is utilizing the cpu 100% ?

  3. #3
    Join Date
    Mar 2007
    Location
    Ft. Lauderdale, FL
    Posts
    3,555
    How many core processors do you have in there and how many processes are in your Run Queue?

    You should be concerned about CPU being at 100% only if (Run Queue > # of core processors)
    Pablo (Paul) Berzukov

    Author of Understanding Database Administration available at amazon and other bookstores.

    Disclaimer: Advice is provided to the best of my knowledge but no implicit or explicit warranties are provided. Since the advisor explicitly encourages testing any and all suggestions on a test non-production environment advisor should not held liable or responsible for any actions taken based on the given advice.

  4. #4
    Join Date
    Jan 2001
    Posts
    515

    I am not sure

    I am not sure of all the details. The server is not supported by myself personally but someone else in our organization.

    My understanding is that they have a server with many different databases that support various applications. Then it seems that one process in one of the databases took up 100% of CPU and froze the box. The only way to get it back was to kill the pmon process and crash the db and then restart.

    I was wondering if there was a way that CPU could be monitored and controlled among many dbs. Resource Manager can only control one db at a time.

  5. #5
    Join Date
    Sep 2002
    Location
    England
    Posts
    7,334
    numebr one reason for one database per server

  6. #6
    Join Date
    Jun 2000
    Location
    Madrid, Spain
    Posts
    7,447
    you said a process consuming 100% CPU, so your concern is really one database

    instead of thinking how to limit the resource I would see why the process is eating all your resources, msot probably its a heavy SQL which might be fixed.

  7. #7
    Join Date
    Nov 2000
    Location
    Pittsburgh, PA
    Posts
    4,166
    Quote Originally Posted by pando
    you said a process consuming 100% CPU, so your concern is really one database

    instead of thinking how to limit the resource I would see why the process is eating all your resources, msot probably its a heavy SQL which might be fixed.
    I agree, you should turn on sql tracing and use tkprof on the trace files. I use "ALTER SYSTEM SET SQL_TRACE=TRUE" and "ALTER SYSTEM SET EVENTS '10046 trace name context forever, level 12';". I leave that on for a while, then turn it off and look at the trace files generated. "tkprof xp10_ora_1544_mytest.trc foo.out sort=prsela,exeela,fchela"

    Jeff Hunter, Marist89, did a blog on tracing awhile back. The sort option on tkprof helps.
    http://marist89.blogspot.com/2005/07/trace-it_04.html
    Last edited by davey23uk; 03-26-2008 at 04:32 PM.

  8. #8
    Join Date
    Mar 2008
    Posts
    28
    120+ databases is not a recommended one to have it in one server. You may think to segregate into different servers. Most of the time, CPU process shoots up reason is query. Either you may use statspack or ADDM to identify the cause.

  9. #9
    Join Date
    Apr 2003
    Location
    Pune,Maharashtra. India.
    Posts
    245
    120+ databases on single server .
    who did that? and next question is how ?
    Rgds
    Parag

  10. #10
    Join Date
    Jun 2000
    Location
    Madrid, Spain
    Posts
    7,447
    Quote Originally Posted by Ravi_2008
    120+ databases is not a recommended one to have it in one server. You may think to segregate into different servers. Most of the time, CPU process shoots up reason is query. Either you may use statspack or ADDM to identify the cause.
    who said there are 120?

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


Click Here to Expand Forum to Full Width