Re: Database Performance Problem between 3:00PM and 4:00PM

On Oct 22, 1:04 pm, zigzag..._at_yahoo.com wrote:
> On Oct 22, 1:46 pm, joel garry <joel-ga..._at_home.com> wrote:
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> > On Oct 22, 8:12 am, gazzag <gar..._at_jamms.org> wrote:
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> > > On 22 Oct, 15:56, zigzag..._at_yahoo.com wrote:
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> > > > I am Windows 2000 server using Oracle 9.2.0.6. We have strange problem
> > > > where by database becomes extremely slow between 3:00PM and 4:00PM.
> > > > Same queries which take 15 seconds before 3:00PM (e.g., 2:55PM) take
> > > > 3-4 minutes at 3:00PM and after that. Poblem starts right at 3:00PM
> > > > every day. No of users etc are same. We have asked users not to use
> > > > the system during that period for isolating performance problem,
> > > > without any success.
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> > > > When one looks at CPU Usage, Memory Usage and Disk Usage nothing
> > > > changes between 2:55PM and (3:00PM-4:00PM). I kooked at task mgr, no
> > > > new processes. I have looked at Windows scheduler, Oracle dbms_job.
> > > > Nothing is running between 3:00PM-4:00PM. I have no clue why system
> > > > becomes so slow in that period. I was hoping that some job starts at
> > > > that time, but cannot find any. Any ideas for troubleshooting will be
> > > > appreciated.
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> > > The most likely explanation is that something else is running against
> > > the database between those times. Note: this process need not
> > > originate from the database server itself, hence nothing in Task
> > > Manager, Scheduled Tasks and DBA_JOBS.
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> > > Monitor V$SESSION for any suspect sessions.
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> > > HTH
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> > > -g
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> > I agree, and the first thing I would look for is some performance
> > monitoring tool!
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> > When I was taking networking (circa 1982) in school, my professor was
> > the fellow who had done the arconet, which connected AM/PM minimarts
> > with a 9600 multidrop line. It had just been shutdown due to
> > insufficient performance. Anyhow, he told a story which totally
> > cracked me up. I've posted it before, but can't remember where, so
> > apologies to those who've heard this before. Imagine a thick
> > Hungarian accent...
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> > As I recall the story went, a particular subnet would shut down every
> > night at 9PM. They tried a number of tools (in those days, one wrote
> > ones own), and could only find that some noise started at that time.
> > Finally he went to one of the stores involved and waited until 9, and
> > sure enough it went down. He plugged in a phone (in those days, it
> > was analog), and heard "THIS IS THE VOICE OF GOD!"
>
> > Turns out, a large AM transmitter was nearby, and would start
> > broadcasting a Christian radio show at 9PM every night, overwhelming
> > the data signal via induction.
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> > I've also worked in a couple of industrial areas where the place next
> > door would turn on large machines at particular times, affecting
> > hardware that was not isolated enough. Even my current customer
> > recently got affected by some transient packet storm that overwhelmed
> > one of an hp-ux machine's network interfaces, killing telnetd and the
> > console. It's a dirty, dirty world.
>
> > jg
> > --
> > @home.com is bogus.
> > At least one web page is still up: http://www.sdcountyemergency.com/-Hide quoted text -
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> > - Show quoted text -
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> FRom the beginning we suspected Network to be an issue, We contacted
> our Networking departament, They monitored Network, could not find any
> thing. I have run perfstat, I have run Window's perfmon (for
> monitoring cpu, disk, memory usage..), do n''t see anything different
> between before 3:00PM and after 3:00PM/ It really baffels me that for
> weeks no one has clue on cause of the problem which happens
> consistenetly.- Hide quoted text -
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> - Show quoted text -

I suggest again that you run Statspack at 30 minute intervals between 1 PM and 5PM and examine the reports generated. They may not tell you everything, but they might tell you something which would provide a proper direction for further investigation.

David Fitzjarrell Received on Mon Oct 22 2007 - 13:11:36 CDT