Date: Thu, 22 Nov 2007 19:59:19 +0000 From: "Frank Shute" <frank@esperance-linux.co.uk> To: Andrew Pantyukhin <infofarmer@FreeBSD.org> Cc: questions@FreeBSD.org Subject: Re: lightly loaded php+mysql - high syscall/csw rates Message-ID: <20071122195919.GA10010@melon.esperance-linux.co.uk> In-Reply-To: <20071122094324.GD66812@amilo.cenkes.org> References: <20071122094324.GD66812@amilo.cenkes.org>
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On Thu, Nov 22, 2007 at 12:43:25PM +0300, Andrew Pantyukhin wrote: > > We have a php+mysql web server. It serves 15-20 http requests per > second, resulting in 100-200 sql qps. But according to vmstat(1), > it all peaks at over 500k syscall/s and 100k cswitch/s. The peaks > are quite frequent, even at this load. During the peaks top(1) > shows 30-40k VCSW for mysql and around 1k vcsw for two php-cgi > worker processes. IVCSW is relatively very low for all processes. > > This is a 4-core Opteron HP DL145 G2 server running 6.2/amd64 > generic+quota. I'm considering a switch to 7.0. > > During peaks user/system/idle in top(1) is 20/30/50. > > The question is - is the syscall and csw rates normal or should I > be trying to tune mysql and php more agressively? I'm not hungry > for performance (haven't hit the limit yet), but a couple of days > ago the server stopped responding until a cold reboot (which is > another story) - and now I'm paying closer attention to its > vitals. Andrew, I don't know if you've been following stable@ but there is a long thread there about php performance (amongst other things). http://lists.freebsd.org/pipermail/freebsd-stable/2007-November/038371.html Titled: "2 x quad-core system is slower that 2 x dual core on FreeBSD"[sic] Apologies, if it's not related to the problem you're seeing. (It's over my head). -- Frank Contact info: http://www.esperance-linux.co.uk/misc/contact.html
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