Re: [squid-users] limit squid memory ram use - squid becomes slow when ram full

From: Amos Jeffries <squid3_at_treenet.co.nz>
Date: Sat, 16 Apr 2011 13:11:03 +1200

On 16/04/11 11:56, rpereyra_at_lavabit.com wrote:
>>
>> Given those cache sizes, your Squid box should be using around 110 MB
> of RAM for index plus a little. Even assuming a worst-case of a minutes
> traffic accumulated in transit buffers comes nowhere close to filling
> 16
>> GB up.
>>
>> Some questions that may help narrow down where the slow is coming from:
>> What version of Squid is this?
>> What are your avg object size?
>> How many concurrent client connections?
>> "slow" and "normal" response speeds?
>> Do you notice any change in the Squid->Internet request types during
>> the slowdown? (ie a move to extra MISS/HIT/IMS/REFRESH)
>>
>> And like Michael said the disk IO stats are important to look at. When
> the cache_dir gets to 94% full it will start spending CPU and disk
> cycles on erasing objects. If it reaches 95% a larger portion of cycles
> get used until it drops down below 94% again.
>>
>>
>> Amos
> _______________________________________________________________________
>>
>
> Hi Amos
>
> Thanks a lot to all for the help.
>
> I'm suspecting now that is a problem of I / O. The cache is on the same
> disk that the system, I'll try to put it on a second disc or distributed
> between two disks.
>
> I followed exactly this tutorial (in Portuguese):
>
> http://www.vivaolinux.com.br/artigo/Squid-+-Bridge-+-TProxy-no-CentOS-5.4/
>
> Kernel: 2.6.30.10
> Squid: 3.1.1
> iptables: 1.4.3
>
> All compiled from sources.
>
>> How many concurrent client connections?
>> "slow" and "normal" response speeds?
>> Do you notice any change in the Squid->Internet request types during
>> the slowdown? (ie a move to extra MISS/HIT/IMS/REFRESH)
>
> How to I know those values ?

A rough value, as in whatever they are when you ask, can be retrieved
from the cache manager "info" report. 'squidclient mgr:info'.

If you can taking a peek at that during normal operation and during load
should give a few clues what the difference is or what to look at for
more detail.

Amos

-- 
Please be using
   Current Stable Squid 2.7.STABLE9 or 3.1.12
   Beta testers wanted for 3.2.0.6
Received on Sat Apr 16 2011 - 01:11:07 MDT

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