Re: [squid-users] High CPU usage problem on Squid 2.6 STABLE9

From: Andrew Miehs <andrew@dont-contact.us>
Date: Tue, 30 Jan 2007 21:15:49 +0100

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On 30/01/2007, at 8:51 PM, Robert wrote:
> My connection speed is 45 Mbit max, but real traffic is about 30-35
> Mbit including P2P.

I am not really sure how high the interrupts are allowed to go...
>
> 20:33:10 CPU %user %nice %sys %iowait %irq %soft %
> idle intr/s
> 20:33:15 all 1,00 0,00 1,00 13,20 1,30 22,95
> 60,55 9004,01
> 20:33:15 0 2,20 0,00 1,20 1,00 5,21 89,98
> 0,40 9004,41
> 20:33:15 1 1,20 0,00 2,00 34,87 0,00 2,00
> 60,12 0,00
> 20:33:15 2 0,20 0,00 0,00 6,81 0,00 0,00
> 92,99 0,00
> 20:33:15 3 0,40 0,00 0,60 10,22 0,00 0,00
> 88,98 0,00
>

As you see - you have a quite a high IOWait, and high number of
interrupts.
CPU User is NOT the problem. I would take this to mean either disk or
network issues.

>> Is the latency on sites in the cache? or 'new' sites?
> Hmm i'll see these but eg. openning googll site with squid enabled
> take 1-3 sec.with squid disabled take max 1 sec

>> Are you running as a 'transperant' proxy? or have the users
>> entered the proxy details per
>> hand or per proxy.pak.... ?
> transparent with iptabes redirect command from port 80 to port 3128.

Do you have this problem as well when you do NOT run in transparent
mode? (But still via proxy)...

>> I would probably run aufs rather than diskd - but this should not
>> make a real difference..
>> You have also only configured 3Gs of cache (3x 1G)...
>> You may want to try disabling the disk cache altogether and see
>> how that works - you need to
>> compile with -enable-storeio=diskd,aufs,null
>>
> cache_dir null ? in squid.conf ?

cache_dir null /tmp

this will cause squid not to cache to disk (well not really anyway)

>> I would also increase my cache size to perhaps, 2G.. (How much RAM
>> does the machine have?)
>>
> 2 GB RAM

Try increasing your cache size to 1G, and disabling the disk cache..
- - see if that improves the
matter at all.

Stupid question - are you actually gaining anything by caching this
data? as I can not imagine
that such a small cache (3G) actually helps in any way. You must have
a pretty low hit ratio..

Summed up:

1. Disable transparent caching and try normal browser caching - does
this help?

if this doesn't change anything then try

2. change "cache_dir null /tmp" and increase you cache memory to 1G

Cheers

Andrew
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Received on Tue Jan 30 2007 - 13:15:54 MST

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