Re: [squid-users] number of threads

Florin Andrei wrote:

> On 22 May 2001 19:05:04 -0500, Joe Cooper wrote:
>
>>I wouldn't recommend using async i/o with Squid 2.3.
>>
>
> What is the reason?
>
> I saw in the docs that async-io is a good thing for a loaded proxy, and
> my proxy goes to 100 requests / second.
>
> Wouldn't be a performance drop without async-io for squid-2.3?

2.3 is not very stable when compiled with async i/o. At least not in my
benchmarks. It also begins to lose hits as it gets a bit of load on it.
  I found that hit ratio, during benchmarks, would drop from 55% to
under 30%. This is a result of the load shedding techniques used in
2.3...2.4 is much improved in this regard, and has proven pretty stable
in my testing so far (I have had a couple of random crashes, but could
never track down the source..and they were in 2.4PRE versions).

>>And I also don't
>>know that Irix is one of the supported platforms for Squid's async i/o
>>implementation.
>>
>
> I just compiled squid-2.3 with async-io on Irix, i'm running some
> Polygraph benchmarks on it, it's going up to 200 req / sec and it seems
> to do fine (in the short amount of time since i started the tests). The
> performance is about the same as with 2.4-diskd (very roughly).

In that case, perhaps Irix is close enough to Solaris and Linux to work
fine for async i/o. I have never use Squid on Irix, so I don't know.
Maybe Adrian knows more about it, since I think he has done some work on
Irix with Squid.

>>That said, yes...32 thread would be fine for 2 disks. Squid 2.4
>>automatically configures 12 threads per disk, I think. It's probably
>>wise to use 2.4 if you are going to use async i/o. But I don't know how
>>it works under Irix.
>>
>
> I'm trying to avoid 2.4 because of the memory leaks. I did my best to
> keep 2.4 on our production system, but it seems it's just too early to
> use 2.4 on Irix, on a busy proxy.
> See my previous message on the mailing list (sent today, subject "memory
> leaks on squid-2.4").

Interesting. I haven't seen a memory leak in 2.4...but then I haven't
done long term tests yet.

                                   --
                      Joe Cooper <joe@swelltech.com>
                  Affordable Web Caching Proxy Appliances
                         http://www.swelltech.com
Received on Tue May 22 2001 - 20:13:10 MDT