Re: [squid-users] slow reconfigure on squid3

From: Marcus Kool <marcus.kool_at_urlfilterdb.com>
Date: Mon, 02 Jul 2012 10:44:23 -0300

Squid reconfigure can indeed take a long time. Especially when Squid
uses lots of memory and starts helpers. Starting helpers takes a
large amount of kernel resources when Squid is large, e.g. 2+ GB
since it forks itself and replaces its copy by a new process. The
fork can take a long time. If you use a URL rewritor you can
easily have 24 or more of them and this makes 24 copies of a large
process.

How large is squid ?
Can you post the output of
    ps -o pid,stime,sz,vsz,rss,args -C squid

I wrote a test program to test the performance of forking X times
a large process. I can post it if you are interested.

Marcus

On 07/02/2012 05:08 AM, Mr J Potter wrote:
> Hi all,
>
> Does anyone have any tips on how to fix this issue:
>
> We've just moved to squid3 from squid2, and now when we do squid3 -k
> reconfigure we get about 30 seconds of squid refusing/failing to
> forward requests while it rejigs itself. I don't know if this is
> squid3 rescanning the cache or doing something with squidguard (we
> have a fairly complex+large squidguard setup)? I don't think this
> happened with squid2.
>
> What can we do to make this less noticeable?
>
> - make it reconfigure faster?
> - multiple squid servers - can we do failover somehow (either proxy
> DNS record points to them both, or they automatically redirect (is
> this what cache peers are for?))?
> - go back to squid 2 - I didn't see any end user benefits of squid3
> over squid2...
>
> any help would be greatly appreciated.
>
> thanks
>
> Jim Potter
> UK
>
>
Received on Mon Jul 02 2012 - 13:44:26 MDT

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