Re: [squid-users] cpu load boom when rotate the access.log(coss filesystem)

Felix New wrote:
> thanks for your reply
>
> 1. the version i used is 2.6.STABLE19
> $ squid/sbin/squid -v
> Squid Cache: Version 2.6.STABLE19
>
> 2. the os is red hat enterprise edition 4 update 4, and the file
> system of cache dir is ext3, cache_dir is coss:
> the cache_dir line in squid.conf:
> cache_dir coss /cache/coss 8000 max-size=1000000 block-size=512
> max-stripe-waste=32768 membufs=30

Ah a few problems with COSS. Firstly it does not handle large objects
very well.
Secondy its reload requires reading into memory the entire cache_dir
slice by slice. Which is extremely slow the larger the dir.

You would get better performance splitting your cache into two
cache_dirs one COSS (max around 2GB) for small objects and one ufs/aufs
for large objects.

>
> by the way, i want to know whether the time is random when squid
> rebuild its cache_dirs? it rebuild the cache_dirs when start, and i
> found it rebuild them random running and i didn't restart that
> process.
>

I don't think its random. It occurs at startup then on timed events
afterwards if squid has enough spare cycles. It my appear random if the
general server load delays or stops any given store checks.

COSS may even do a rebuild based on other criteria I don't know of.

Amos

> 2008/3/26, Amos Jeffries <squid3@treenet.co.nz>:
>> Felix New wrote:
>>> hi all,
>>>
>>> i have used aufs file system for a few days and that is very good.
>>> but i encounter a question when i chang the aufs to coss: the cpu load
>>> is very very high(100% nearly) when i rotate the squid access log file
>>> with command 'squid -k rotate', and can not fall down.
>>>
>>> i google that and find a article about
>>> that:http://www.freeproxies.org/blog/2007/12/29/advanced-squid-issues-upkeep-scripts-and-disk-management/
>>> ---------------------------
>>> If you have a script rotate your squid logs (as you should have),
>>> and the squid cache is rebuilding when you are rotating your logs,
>>> squid will not accept any more connections until it has finished
>>> rebuilding the storage.
>>> ----------------------------
>>> is this a squid bug?how to fix it?
>>>
>>> thank you.
>>>
>>>
>> FAQ #1: Which squid release are you using?
>>
>> FAQ #2: What exact configuration are you using (minus default comments)?
>>
>> Also: What system setup do you have underneath squid? disks and
>> cache_dirs, etc.
>>
>> Amos
>> --
>> Please use Squid 2.6STABLE17+ or 3.0STABLE1+
>> There are serious security advisories out on all earlier releases.
>>
>
>

-- 
Please use Squid 2.6STABLE17+ or 3.0STABLE1+
There are serious security advisories out on all earlier releases.