Re: [squid-users] are there large customers that run Squid on solaris/sparc platform?

From: Michael Pye <michael@dont-contact.us>
Date: Mon, 08 May 2006 23:46:11 +0100

AF_INET@web.de wrote:
>> I would guess that Linux currently is the best performaning OS if you apply the
>> epoll patch.
> Hum. Can you give us some more details why you think that Linux will perform better?
> Chris

In my experience the limiting factor on squid performance is cpu usage
with the poll syscall being the main culprit. As soon as you start
getting large amounts of file descriptors, poll becomes very inefficient.

In other words, the network i/o sub-system and the solaris poll system
call present a limit. I've seen about 250 requests per second at 85% cpu
usage (admittedly on a low-end ultrasparc IIe 650mhz). It will probably
surpass that but not by a huge amount.

The linux epoll is much more efficient and doesn't use anything like the
large amounts of cpu that poll does when hundreds of file descriptors
are in use. This is the reason I would guess Linux would be better
peformer; this is pure conjecture however, I don't have anything to back
this up.

Linux has epoll and freebsd has kqueue. The solution for solaris is to
move to /dev/poll or event ports. Some work on /dev/poll has been done
in the past by Adrian Chadd and I'm hoping this will be a future feature
of squid.

Don't get me wrong - I think solaris is a great OS for running squid on,
but at the moment probably not the top performing one.

http://developers.sun.com/solaris/articles/polling_efficient.html
http://developers.sun.com/solaris/articles/event_completion.html

--
Michael
Received on Mon May 08 2006 - 16:46:16 MDT

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