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

From: EdStevens <>
Date: Tue, 23 Oct 2007 05:48:43 -0700
Message-ID: <>

On Oct 23, 5:11 am, gazzag <> wrote:
> On 22 Oct, 18:46, joel garry <> wrote:
> > I agree, and the first thing I would look for is some performance
> > monitoring tool!
> > 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...
> > 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.
> > 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
> > --
> > is bogus.
> > At least one web page is still up: quoted text -
> Great story :-)
> I used to work for the Ministry of Defence here in the UK. We had an
> issue once where the database server on an army site, for no apparent
> reason, would reboot at random intervals. Needless to say , it was a
> high-profile system and the army top-brass were making one heck of a
> racket to get it sorted. We even had the local electricty company in
> as, initially, I suspected power surges from the mains. None of the
> data we accumulated corrolated with anything; the problem seemed
> genuinely random. We had memory changed, CPU's changed, even the
> whole damn motherboard went through a few incarnations, yet still the
> problem persisted. The army started blaming the hardware supplier and
> there was even talk of contracts being terminated and a new system
> being sourced.
> Then, one day, while sitting in the server room, mulling over and over
> all the different things we'd tried, and all the things that had
> failed, a slow rumble of realisation began to form in my mind. But
> then the rumble got louder and louder and louder. I started to
> realise that the rumble that I thought I was imagining was real when
> the floor began to shake. I jumped up and ran to the window to see
> what the heck was going on. Then I saw the likely cause of our
> problem as 60-something tonnes of Challenger tank (http://
> hoved into view and made a
> right turn past the server room.
> It wasn't power surges or network glitches; merely disks and disk-
> heads being almost rattled out of their casings :-)

Or maybe having PC-Anywhere configured to reboot when a remote console disconnects . . . Received on Tue Oct 23 2007 - 07:48:43 CDT

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