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From: "Ali Niknam" <ali@transip.nl>
To: "Varshavchick Alexander" <alex@metrocom.ru>
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Date: Fri, 4 Jun 2004 17:30:41 +0200
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cc: freebsd-hackers@freebsd.org
Subject: Re: FreeBSD 5.2.1: Mutex/Spinlock starvation?
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Hi Alexander,

> I can't say anything as how the issue can be connected with the
> mutexes and so on, but to solve your problem with apache, I'd look
> into 'hold_off_on_exponential_spawning' and 'MAX_SPAWN_RATE'
> parameters in src/main/http_main.c of the apache source tree
> (presuming you're using apache 1.3.*), and I'm sure some similar
> options can be found for apache
> 2.0. What you need is to make apache forking rate more slower, so the
> server will not suffer from a sudden load peak.

That was my first thought exactly! I halved the MAX_SPAWN_RATE to 16 (from
32) and then *exactly* the same thing happened; it only took a minute longer
to happen ....

If i recall correctly (not sure anymore since it was middle of the night)
other processes also got blocked (hence i couldnt use keyboard anymore).

That was why i figured it was some kind of lock/block/mutex/whatever inside
the kernel....

Best Regards,
Ali Niknam