High Performance Web Caching With Squid

Thanks for doing this article!

-H

Subject says it...

I agree it's very linux specific. I use a cache Joe has put together. While we run FreeBSD on just about everything, he made some very convincing arguments for Linux for this application, based on things like the ReiserFS, and a couple other topics I can't remember right now.
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I wouldn't doubt there are some great optimizations for FreeBSD and Squid. They'll be different than Linux and Squid. This is one way to go about the job, and a very good one from what I can see. I'm interested in hearing any good FreeBSD (or other OS) and Squid stories.
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How to setup using socket protocol with Squid?

Hey,
Finally a guy that gives better instructions on how to achieve maximum speed without all the other useless information usually found in optimization
articles.
From my own experience I believe that tweaking around with hdparm when using IDE drives also seems to help, especially on older machines used for smaller caches.
Anyway, Well done dude and thanks!

You're right. It is really only of interest to Linux users. It's what I know about, really. There is also the problem of FreeBSD not being able to use the kernel threading model required of the currently fastest Squid available.
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Squid 2.4 now has the nice DiskD shared memory processes for IO on FreeBSD, and Adrian Chadd has been doing interesting things with kqueues in the commloops branch in CVS, also, which should improve performance on FreeBSD. The DiskD Squid is not as fast as a threaded Squid, but it is much faster than the single process Squid.
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Those things will get you a moderately fast Squid. And I imagine they will improve more over time (Swell is going to make sure Squid gets faster all around, and especially under Linux).

You're very welcome, and you're right. hdparm is an important tool for tuning your system performance in general if you use IDE. It can be used to nudge a hesitant DMA drive into actually operating in DMA mode:
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hdparm -d1 /dev/hda
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I've found this to be the only really effective option for tuning for Squid. I've experimented with every other option, but found none really made measurable difference. Forcing higher PIO modes can help sometimes, though the driver usually chooses the best mode. For example, to switch to UDMA 66 mode 2:
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hdparm -X66 /dev/hda
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or to try for mode 4 (which only works on about half of the UDMA drives in our office):
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hdparm -X68 /dev/hda
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The manpage for hdparm goes firmly against manpage convention by actually making sense, so it's a great place to go for help on the subject.
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I'll keep this in mind next time I update this article. Thanks for the reminder.

what exactly PHP?try to answer in simple terms

I found the Squid Server support four protocols , but no socks protocol.
how to resolve it?

Many thanks for your excellent articles, especially on squid, and for this web which is very good to me.

What would you think of running squid on a machine such as that described by you, along with other services such as httpd and possibly a mail server? I admin a network of about 100 computers, using the one proxy to access the web. I am also considering installing a httpd on this machine. Do you think it's wise?

Yes. Just remember , you can set the priority of your services on the linux box.
I am running apache , mail , dns on a Pentium pro 200 , with 512 Mb ram .PLUS i am running a mail virus scanner as well , and I have no problems

Dear Joe, Can I follow your optimization step if i use squid 2.4.stable1 version ? Which step should I adjust in order to get good squid performance with 2.4.stable1 ?

what about freebsd? how can i improve the performance of squid?