Re: SMP scalability goal

On Thu, Apr 24, 2008, Alex Rousskov wrote:

> My wording may have been poor. I assume we always use a quad box. Add
> SMP support to Squid. Test Squid3 on that quad box with SMP disabled
> (that is what I called single-core performance on a quad box). Test with
> SMP enabled and configure Squid to use two (out of four) cores. Test
> with SMP enabled and configure Squid to use three (out of four) cores.
> This will give the 1-2 and 1-3 comparisons I was asking about.
>
> What I would like to do now is to estimate the difference between those
> future results. In other words, what kind of scale should we expect
> after 5-10 months worth of work, very roughly?

Uhm, i'd start by benchmarking where your current bottlenecks are.
If your bottlenecks are memory-bus related, threading Squid won't help (much).
If your bottlenecks are CPU related then theading Squid will help a bit.

> > * Ok. Look at the performance of varnish, apache2-thread and memcached.
> > memcached is a good one. They get reasonably linear performance up to quad
> > core iirc where things like memory transaction rates impose limitations on
> > performance.
>
> Do you have any pointers to varnish, apache2-thread, or memcached
> performance related to mutli-core scale?

Trying to find some. But people run memcache + varnish on systems and seem to
get linear-scalability. Of course, quad-core and quad-CPU are different beasts
and I bet some of these large installs have >1 socket..

Adrian

-- 
- Xenion - http://www.xenion.com.au/ - VPS Hosting - Commercial Squid Support -
- $25/pm entry-level VPSes w/ capped bandwidth charges available in WA -