Performance of system is slow
Posted in 2003
Topics: Performance & Tuning
Hi, At peak hrs, i find that one of the program which usually takes few seconds to complete a process takes even 11 minutes... Even small SQL execution is taking time... This is not specific to a particular program/SQL.. Can anyone let me know what could be the reason.. What are all the things i need to check. Thanks in Advance. Arul
You
need to start gathering some information using onstat.
Start with looking at:
I would suggest you start with
onstat -u -r 2.
See what flags are showing up against the user processes [you can largely
ignore all the sessions with flags like Y--P, P--F, P--B, P--D]. The -r flag
causes onstat to run repeatedly, every 2 secs in this case. You can adjust
it accordingly. I have attached a script that will filter the output,
assuming you are using a unix system. The script loops forever. You need to
use CTRL-C [whatever your interrupt setting is] to stop it.
Also check the output of onstat -p. Look at ovbuff and ovlock. For ovbuff is
high and you don't have many buffers configured then I would suggest you
increase BUFFERS. If ovlock is high you should add more LOCKS.
These are just 2 quick items to look at.
Mark
----- Original Message -----
From: "Arulmaran M...." <Arulmaran.Mohanam@caritor.com>
To: <ids@iiug.org>
Sent: Tuesday, September 02, 2003 05:53
Subject: Performance of system is slow [1780]
>
>
>
>
> Hi,
>
> At peak hrs, i find that one of the program which usually takes few
seconds
> to complete a process takes even 11 minutes...
> Even small SQL execution is taking time...
> This is not specific to a particular program/SQL..
> Can anyone let me know what could be the reason..
> What are all the things i need to check.
>
> Thanks in Advance.
>
> Arul
>
>
I would
try and start bottom up from the os:
1) is it a cpu bottleneck (use os tools like sar and vmstat)?
2) is it a disk bottleneck (os tools like in 1)?
3) if it is not 1) something must be blocking in the server.
Use onstat -g ath and -g act to see what the sqlexec
threads are doing. Check locks, bufwaits, etc. etc.
Depending on what you find we then could talk about what to look at
next. Mark's advice is definitely one of the choices here.
Michael
Mark Denham wrote:
> You need to start gathering some information using onstat.
>
> Start with looking at:
>
> I would suggest you start with
>
> onstat -u -r 2.>
> See what flags are showing up against the user processes [you can largely
> ignore all the sessions with flags like Y--P, P--F, P--B, P--D]. The -r flag
> causes onstat to run repeatedly, every 2 secs in this case. You can adjust
> it accordingly. I have attached a script that will filter the output,
> assuming you are using a unix system. The script loops forever. You need to
> use CTRL-C [whatever your interrupt setting is] to stop it.
>
> Also check the output of onstat -p. Look at ovbuff and ovlock. For ovbuff is
> high and you don't have many buffers configured then I would suggest you
> increase BUFFERS. If ovlock is high you should add more LOCKS.
>
> These are just 2 quick items to look at.
>
> Mark
>
>
> ----- Original Message -----
> From: "Arulmaran M...." <Arulmaran.Mohanam@caritor.com>
> To: <ids@iiug.org>
> Sent: Tuesday, September 02, 2003 05:53
> Subject: Performance of system is slow [1780]
>
>
>
>>
>>
>>
>>Hi,
>>
>>At peak hrs, i find that one of the program which usually takes few
>
> seconds
>
>>to complete a process takes even 11 minutes...
>>Even small SQL execution is taking time...
>>This is not specific to a particular program/SQL..
>>Can anyone let me know what could be the reason..
>>What are all the things i need to check.
>>
>>Thanks in Advance.
>>
>>Arul
>>
>>
>
>
>
>
--
=== Michael Mueller ==================
Tel. + 49 8171 63600
Fax. + 49 8171 63615
Web: http://www.mm.kay-mueller.de
http://www.planets.kay-mueller.de
======================================