[squid-users] Re: Improving squid-performance

On Tue, 2005-02-22 at 16:10, Stefan Neufeind wrote:
> Ow Mun Heng wrote:
> > On Tue, 2005-02-22 at 08:13, Stefan Neufeind wrote:

> > Did you ever determine what the bottleneck was in the 1st place?
>
> I'm not too sure how to adequately check that. The system is running
> with 99.XXX% for squid from time to time, all memory is used, most cache
> is not - that's what I expected. In top, from time to time, the
> system-part of cpu-usage raises to 25% or so. So I guess it might have
> to do with harddisk-access, together with network I/O maybe. That's why
> I hope diskd can help (read below).

Okay.. when you talk about "most cache is not" I have no idea what that
means. Please explain.

Also, note that for any partitions which you are using "solely" for
squid's cache, you should not be devoting the _entire_ partition to
squid, rather only ~80% as stated in the cache_dir directive in
squid.conf

This is to permit squid to breathe so to speak. (I forgot what the
_actual_ technical term is)

If all memory is used, can I ask how much of memory are you giving to
squid? There's a math in getting the amount of memory per cache. It's
like ~10MB RAM for every 1GB of cache. (IIRC)

> >>So I thought how performance can be improved. Okay, increasing
> >>mem (currently 1GB) might help. But what other options are available?
> >
> > memory is one option but I doubt it will help unless you know why it's
> > using 100% CPU. I'm certain you're not running any sort of
> > antivirus/filtering app right?
>
> For sure not running any sort of this :-) Let me explain: It's an
> external webserving "cluster" with two machines behind it. People
> accessing the webservers only access certain sites that are placed on
> those servers. No big files (maybe up to 50 or 100kb), but many. Caching
> helps the webservers a lot - I see that from hit-stats.

That's called a reverse proxy and I know what it's supposed to do. :-D

> > cache? Can you determine if the load is caused by internal or external
> > users?
>
> Just those two servers.

Okay.. so no internal users

>
> >>Onn the Fedora-mailinglist I found your message:
> >>https://www.redhat.com/archives/fedora-list/2004-November/msg04242.html
> >>Were there eany replies to this (which I didn't notice)? Did you find
> >>any good howto's? What steps did you take?

Ah... Was searching the wrong list :-|
> High Performance Squid - Howto
> * From: Ow Mun Heng <Ow Mun Heng wdc com>
> Does anyone here has any pointers on installing a high performance
> Squid?

Nope... No one replied :-[

> > fine w/ 4096 descriptors.
>
> I did recompile squid with a higher number of descriptors. But after
> reading several posts about this topic I wonder if I need to raise some
> limit on the system itself as well? However, squid does not yet complain ...

You will know cos you will see it in the system logs. If they don't
complain and if your site's not very busy, then it's fine.

> >>What does this diskd do? I didn't find much information about it. Only:
> >>http://www.squid-cache.org/Doc/FAQ/FAQ-22.html
> >
> > Diskd is just another cache filesystem like aufs. I can't tell you more
> > than that. But diskd is supposed to function the best on *BSD systems.
> > on Linux, aufs is the better choice. (AFAIK)
>
> Ouch. Too bad. I hoped to see a perforrmance-improvement by using diskd.
> Hmm - maybe I'll try out

If you do.. let us know the results then.

> - but I hoped it might be benefishial. On
> squid-cache.org it's written like it should be an improvement in general
> - however I've read that some kind of message-queues need to be
> supported by the kernel, so maybe that's why it's not the standard
> storage-interface. Are the necessary functions already available on a
> FC3 2.6-kernel, do you know?

Look here.. Not sure if it helps but found the link in one post in
squid-list

http://www.perl.org/tpc/2002/sessions/wessels_duane.ppt

> > Raw Partitions? I don't now about that. Maybe someone on the list would
> > know??
>
> Haven't read anything in the archives. Was just a crazy idea :-)

Hmm.. can't help you on that. but if you do find something. Let the open
source world know

>
> Thank you for the quick reply,

Cheers. I scratch your hairy back, you scratch mine :-)

> Stefan

--
Ow Mun Heng
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