Re: Slowness of Squid without any apparent reason

From: Ong Beng Hui <ongbh@dont-contact.us>
Date: Sat, 2 Nov 1996 20:45:59 +0800 (SST)

> > Configuration :
> >
> > cache_mem 130
>
> Decreased to 110 Mb. ps shows Squid is still too large (I discovered that
> "info" in cachemgr shows a lot of useful info about memory consumption.
> Squid eats a lot of memory so do not use a cache_mem too close from your
> physical memory, you need memory for other things). Swapping is still low.

Swapping is bad. If you are out of memory, reduce cache_mem
until it fit into the memory nicely. And, size your cache_swap
with repect to the memory. If possible, buy more memory. And
Nope, I am not a DEC sales person. ;)

> > cache_swap 14500
> >
> > (We have 320 Mbytes of RAM. The cache disk is 100 % full.)
>
> I decreased TTL and now the cache is no longer full. cache.log shows no
> more garbage collecting.

14.5 Gig of disk with 320 MBytes of memory should be
enough. You are right about decreasing TTL such that Squid
does slightly less gc.

> David Luyer <luyer@ucs.uwa.edu.au> suggested not to use ADVFS (we don't)
> for the cache and to have several separate cache-dir (we have near 7300
> files in each directory which is quite slow to process) or to go to Squid
> 1.1 with its two-dir level. (Not yet tried.)

Yup. Don't use AdvFS, it is slow. Use UFS. Maybe you can
advise on your disk origanization. Split the disk up.
RAID 0 might not be useful for Squid. Use multiple directories,
keep your directory small (around 10K) or configure Squid
to use multiple level directories. I believe Squid uses
3 level of directories now.

> Thanks to all those who searched, still looking for advices,

Depending on your OS version. Tune it. This is a _must-do_
for large scale proxies. Increase your somaxconn, sominconn
tcbhashsize.

Check out
http://www.digital.com/info/internet/document/ias/tuning.html
for tuning instruction.

Remember to install the DU ping patch.

Maybe you can provide us with more detail on your
server setup. I hope I can help you scale your machine
further. I got couples of DEC AS4100 serving 1.5 millions
hit per day without performance problem.

*8)
Ong Beng Hui
ongbh@singnet.com.sg
...yet another day in an ISP business
...and they lived happily ever after
Received on Sat Nov 02 1996 - 04:46:11 MST

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