Re: [squid-users] Re: slow browsing in centos 6.3 with squid 3 !!

On 22/02/2013 9:57 p.m., Ahmad wrote:
> hi ,
>
> i want to say that the problem exist in the presence and absense of
> squidguard .
>
> i note that the storing on the hardsik is slow relative to the users pumped
> to squid !!

Yes. You are using RAID.

http://wiki.squid-cache.org/SquidFaq/RAID

RAID-0 gains you a few things:
  - fast write of large files ... Squid stores mainly small files.
  - fast read ... Squid mainly writes to disk, although in newer Squid
this is being optimized back towards 60:40 read/write ratios.
  - larger disk size ... disk size is largely irrelevant to Squid.
Simply use cache_dir of mixed sizes.

You _loose_ :
  - ability to retain disk 1-3 contents when disk 4 fails. Squid must
rebuild the entire cache after restart when one disk fails instead of
just the lost disks portion.
  - ability to use AIO threading per-cache_dir in Squid. Cuts the disk
I/O driver threads opened by Squid down to 1/3 what would be opened with
three cache_dir.
  - ability to measure individual disk usage and loading (ie guage wear
and tear) from Squid disk I/O reports.
  - ability to optimize object storage by size - paired Rock+UFS
constellations require assigning 2 cache_dir of specific types per
physical drive.

Still think RAID-0 is good?

The best thing you can do for performance is drop RAID entirely. All
RAID gains you with Squid is some advance warning when disks fail -
which can be used to replace the disk under Squid with minimal outage
time. For that RAID-1 is the one to use despite the CPU overheads which
are still incurred as a trade for constant uptime.

> did u have a look on squid.conf file ?

Yes. There are a lot of issues there.

Please start by running squid -k parse and take a look through all the
warnings which should appear. Fix as many as you are able - if your
Squid is new enough it should pick up all the worst problems and
indicate how to fix them. It does not yet pick up many performance type
config problems, which I will go over later, but if you could clean up
the basic issues and repost the fixed config without the # comment lines
it will help avoid getting side-tracked on minor things like removing
the duplicate ACL definitions.

PS. I see you are on 3.1.10. If you can upgrade to 3.2 or 3.3 you will
get a lot more issues detected, a lot faster basic processing speed out
of Squid and better HTTP/1.1 compliance with the extra speed benefits
that brings.

Amos
Received on Sat Feb 23 2013 - 03:44:56 MST