Date: Fri, 10 Aug 2007 09:29:16 -0300
after reading this email, i switched from aufs to diskd to see
performance of them under high load ..
with aufs, squid never used more than 10% of cpu and response time is
very low (5ms to 150ms).. with diskd cpu usage goes to 50% +- and
median response time up to 900ms !!
i´m running CentOS 5.0 with kernel 2.6.22, quad opteron 64 bits with
4gb ram and hd are SAS 15.000 rpm
attached graphic of cpu usage !!
On 8/10/07, Michel Santos <michel@lucenet.com.br> wrote:
>
> Henrik Nordstrom disse na ultima mensagem:
> > On fre, 2007-08-10 at 06:50 -0300, Michel Santos wrote:
>
> >> what is what you agree to be broken beyond the shutdown issue?
> >
> > Bug #761 unstable under high load when using diskd cache_dir
> >
> > diskd falls over under load due to internal design problems in how it
> > maintains callback queues. Duane fixed most of it quite recently so it's
> > no longer near as bad as it has been, but there is still stuff to do.
> > The problems was first reported 5 years ago.
> >
>
> indeed the cpu load went extremly down after this changes, I won on much
> machines more then 30-40%, or better 70/80% cpu load felt down to 30-40%
> overall. That was very good
>
> but I could get araound of it before and still do using at least 2 or
> better 4 or more diskd processes
>
> >> ok you mean threads instead of pthreads right?
> >
> > I don't know the FreeBSD thread packages very well to call them by name.
> > I only know there is two posix threads implementations. One userspace
> > which is what has been around for a long time and can not support aufs
> > with any reasonable performance, and a new one in more current releases
> > using kernel threads which is quite capable of supporting aufs.
>
> it it pthread versus thr (kernel threads) and who is interested, it's easy
> to do on 6.2 by creating /etc/libmap.conf or adding if exist, no further
> compile thing is necessary
>
> [/usr/local/squid/sbin/squid]
> libpthread.so.2 libthr.so.2
> libpthread.so libthr.so
>
>
>
> Michel
> ...
>
>
>
>
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