Re: run in queue (Solaris)

Forgot one thing - if there was only one query running when you were seeing a runqueue of 30, most probably the query used PQ slaves ... I've seen systems with large degree of parallel degree generating a large runqueue ... now, if you 'simply' killed the query what exactly do you mean... a kill -9 of the dedicated server or an alter system kill session. If you kill the query coordinator with a kill -9 I don't know how Oracle would react but I guess SMON or PMON should detect this and clean up your mess. This could explain why your runqueue does not drastically decrease immediate after your kill but only after a while... BTW - the command uptime actually displays the average runqueue length over 5min, 10min, 15min period ...

Cheers,
Koert

"koert54" <koert54_at_nospam.com> wrote in message news:9jup7.59207$6x5.12753057_at_afrodite.telenet-ops.be...
> The r field in vmstat is the count of processes that are currently
runnable.
> However, depending on the platform specific implementation, this may or
may
> not include
> the number of jobs running on the CPU(s).Example - SunOS 4.1(and most BSD
> implementations)
> include both the number of jobs running on the CPUs and those waiting in
the
> queue. Solaris on the
> other hand excludes the running jobs.
> Say you have 5 runnable jobs on a 2way box :
> - running SunOS 4.1 : the r column shows 5
> - running Solaris : the r column shows 3
>
> The r column is a very good indicator if the machine is CPU bound. If you
> constantly having 5 runnable jobs
> on a 2 way box, adding 3 CPU will prove very valiable and should boost
> performance. However - having
> constantly 2 runnable jobs on a 12way box is a waste of money ... 2 CPU's
> would have been sufficient.
> Typically, a runqueue of 3 to 4 times the number of CPU's will bring your
> machine to a crawl because the CPUs
> are forced to jump between the runnable jobs.
> In your case a runqueu of 30 is a lot if you only have 4 CPU's - but ok if
> you 24CPUs...
>
> A great book on this matter (besides 'The design of the Unix operating
> system') is "Optimizing Unix for Performance"
> by Amir H. Majidimehr.
>

http://www.amazon.com/exec/obidos/ASIN/0131115510/qid=1000763299/sr=2-2/ref=
> aps_sr_b_1_2/002-2667980-3793602
>
> Cheers
> Koert
>
> "Jens" <superglad7_at_hotmail.com> wrote in message
> news:TWtp7.5603$sn6.611353_at_newsc.telia.net...
> > Hi all
> >
> > This question should maybe go to a Solaris newsgroup but i´ve hope some
> > DBA´s out there could answer this one pretty quick and easy..
> > To the question:
> >
> > When running a "vmstat" on my Solaris 8 i could see a lot of "run in
> queue",
> > about 30 or
> > more!
> >
> > I´ve searched for processes and found one process containing a suspect
> query
> > to the Oracle database wich contained a lot of wildcards and so on wich
> i´ve
> > simply killed.
> > Afer this the system answered much faster.
> >
> > But, now to my question, what exact does "run in queue" tell me..?
> > After killing the process the "run in queue" wasen´t down to zero
> > immediately but slow decreasing.
> > Now, after alomst 30 minutes the run in queue is down to about 3 or so
and
> > soon to be zero if i´ve know the system right..
> > Is this what i´ve should expect or more exactly, coul´d someone please
> tell
> > me a bit more about "run in queue" and what this really means..?
> > Regards
> > Jens
> >
> >
> >
> >
>
>
Received on Mon Sep 17 2001 - 17:03:27 CDT