Re: [squid-users] Squid 2.6 + COSS comparison

On Tue, Sep 19, 2006, Matus UHLAR - fantomas wrote:
> On 19.09.06 10:11, Adrian Chadd wrote:
> > The COSS code in Squid-2.6 has come quite far from its original design by
> > Eric Stern. Steven Wilton has put an enormous amount of effort into the
> > COSS design to fix the remaining bugs and dramatically improve its
> > performance.
> >
> > I've assembled a quick webpage showing the drop in CPU usage and the
> > negligible effect on hit-rate. Steven Wilton provided the statistics
> > from two Squid caches he administers.
> >
> > You can find it here - http://www.squid-cache.org/~adrian/coss/.
>
> Great. Did you play with max-size option to try to find out at which size
> the efficiency of aufs and COSS nears?

I haven't really administered large-scale production caches in a few
years but there's plenty of academic papers circa 1997 which show there's
a clear win doing your own IO vs using a unix FS for object sizes under
a couple hundred kilobytes. Modern UNIX FSes haven't gotten (much) better
in that regard.

COSS is still pretty new and there's not a lot of documentation on how
to tune it. But even the defaults smoke using a normal unix filesystem.
Just start at max-size at, say, 64k or 128k and go from there.
Don't bother going above a few hundred kilobytes.

> > Steven is running a recent snapshot of squid-2.6. The latest -STABLE
> > release of Squid-2.6 doesn't incorporate all of the COSS bugfixes
> > (and there's at least one really nasty bug!) so if you're interested
> > in trying COSS out please grab the latest Squid-2.6 snapshot from
> > the website.
>
> are you speaking about current release (STABLE3) or about stable squid in
> general?

Steven has committed a bunch of bugfixes to squid-2.6 after Squid-2.6-STABLE3
was released. So no, the current snapshots are fine but stable3 isn't.

Adrian
Received on Tue Sep 19 2006 - 02:54:52 MDT