Re: [squid-users] page stalling w/ squid

From: Amos Jeffries <squid3_at_treenet.co.nz>
Date: Tue, 06 Apr 2010 20:49:52 +1200

Mike Leong wrote:
> I have this weird problem where if I go though squid, a page would
> stall until it hits the read timeout limit. This only happens on
> certain webservers.
>
> eg:
> read_timeout set to 120 seconds.
>
> 1. request page on browser
> 2. page load stalls
> 3. after 120 seconds, squid sends a fin, ack to http server
> 4. http server returns a HTTP 200 after receiving the fin,ack packet
> 5. browser gets the requested page.
>
> Sometimes, squid would load the page fine.
>
> Here's my squid build:
> Squid Cache: Version 2.7.STABLE9
> configure options: '--enable-linux-netfilter'
> '--enable-follow-x-forwarded-for' '--enable-linux-tproxy'
> '--enable-epoll' '--enable-async-io' '--with-pthreads'
> '--enable-storeio=ufs,aufs,coss,diskd,null'
> '--enable-removal-policies=lru,heap' '--enable-snmp'
> '--with-maxfd=65536' 'CFLAGS=-march=pentium3 -O2 -fomit-frame-pointer
> -pipe' 'CPPFLAGS=-march=pentium3 -O2 -fomit-frame-pointer -pipe'
>
>
> You can download tcpdump and squid config from
> http://mina.lolipower.org/mike/squid-stall.zip
>
> If I access the page directly on the browser, the page stalling doesn't happen.
>
>
>
> any ideas on addressing this issue?
>

Looks like a TCP stack issue.

The only difference between those traces is the "bad" one has a FIN/ACK
packet playing double duty to ACK bytes of data and close the link. The
"good" only an empty FIN/ACK following the end of the data.

Amos

-- 
Please be using
   Current Stable Squid 2.7.STABLE9 or 3.1.1
Received on Tue Apr 06 2010 - 08:50:13 MDT

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