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Re: oracle cause "load" on OS level very high.

From: Dominica Leung <dominica_l_at_yahoo.com>
Date: 8 Aug 2002 18:30:47 -0700
Message-ID: <5f8af180.0208081730.1ccc1c85@posting.google.com>


Hi,

40 DOES not mean 40 processes.
Itis the "load" on Unix system.
Actually at that moment, it say it is running 970 processes in the system.

You know what, I am NOT USING MTS,
but I should,
let me ask you this, if
I have 970 processes, how many dispatches should I use??

You are right, it could has so many FACT to have load that high. But you know what, I think this company is really MAX out this TINY POOR little machine.
They do 582 select per second. It is a lot. Thanks for your help tough.

my next project is to setup CONNECTION manager, I don't know how yet.

Dominica


"koert54" <nospam_at_spam.com> wrote in message news:<4Qd49.53393$8o4.7093_at_afrodite.telenet-ops.be>...
> if I'm not mistaken the 'load' is the number of runnable processes ... so if
> it peeks to 40 it means
> 40 processes are runnable at that moment ... this could mean that :
> - someone is using parallel query (pq slaves) ?
> - someone wrote some stupid program that connects multiple times
> concurrently is a short amount of time ?
> - dbwriter is using dbwriter slaves ? multiple arch slaves ?
> - a process is spawning a hugh amount of threads ?
> - combination of above ...
> - other reason :-)
>
> My experience is on boxes that show very high runqueues and peaks of high
> runqueues, PQ is being abused - parallel processing
> is not always faster ... one time a saw a box with a runqueue (load) of 80
> to 100 ... reason was a high parallel degree clause on most tables -
> lowering PQ -> low runqueue -> lower overhead, context switches -> increase
> performance ...
> My experience is, depending on number of CPUs, a runqueue/load of 2 to 3
> times number of CPUs is a performance limiet...
>
> "Dominica Leung" <dominica_l_at_yahoo.com> wrote in message
> news:5f8af180.0208061359.6cac32d6_at_posting.google.com...
> > Hi All,
> >
> >
> > I am wondering whether anyone seen this kind of situation
> > before in Performance tuning aspect.
> >
> > I am (this company AA) is running oracle 8.0.6.2
> > 32 bits on
> > solaris 2.6 OS.
> >
> > There is very strange thing happen.
> > When I do a "top",
> > everyday at 2:30 pm and 2:45PM
> > (there are some cronjob from Engr dept doing select and
> > update)
> > the "load" from the "top" command, will be 40.00.
> > This is very high, normal machine is 4 or 5.
> >
> > =========================================
> >
> > last pid: 8806; load averages: 40.00, 8.57, 9.67
> > 14:50:39
> > 928 processes: 923 sleeping, 2 running, 3 on cpu
> > CPU states: 32.9% idle, 54.0% user, 13.0% kernel, 0.0% iowait, 0.0%
> > swap
> > Memory: 4096M real, 133M free, 282M swap in use, 1254M swap free
> >
> > =================================================
> > It only spike up for 3 or 4 minutes.
> >
> > When I do top, I only see the
> > PID is 25923, which is
> > the oracle 25923 1 0 Jun 29 ? 1031:47 ora_dbw0_USRDEV
> >
> > My question is ?
> > 1) is there anything I should look??
> > I have looked at V$lock, v$transaction at that time,
> > there is NO PROCESS waiting for transaction, only 14 locks in the
> > whole system.
> >
> > Curious how to improve it, look like database writer is very busy.
> >
> >
> > I know people might told me "this machine is MAX out" in the
> > capacity. But I hope there is something I could do about it.
> >
> >
> > Thanks,
> >
> >
> > Dominica
Received on Thu Aug 08 2002 - 20:30:47 CDT

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