RE: [squid-users] Squid Cache Strange Errors / Corruption

From: David Choo <davidcch@dont-contact.us>
Date: Tue, 21 Jan 2003 21:59:20 +0800

Thanks for the info. As per what Wei Keong has mentioned, I've set IE to
accept HTTP 1.1 over proxy and it worked.

Its good to know that Squid isn't the problem.

Best Regards;
David Choo

-----Original Message-----
From: hno@marasystems.com [mailto:hno@marasystems.com] On Behalf Of
Henrik Nordstrom
Sent: Tuesday, January 21, 2003 6:18 PM
To: Wei Keong
Cc: David Choo; 'Tom Bell'; 'Squid Cache'
Subject: Re: [squid-users] Squid Cache Strange Errors / Corruption

mod_zip is a problem due to the poor support of Vary in HTTP
servers/clients/proxies, and mod_gzip authors just trying to patch
things up by bending HTTP by not including the required Vary header in
the reply instead of convincing HTTP server/agent/proxy authors to
implement Vary support..

It is a rather sad story on all fronts, and is likely to take years
before there is significant improvements.

To make the story short: The mod_gzip currently have the options of
either "corrupting" shared caches by sending gzipped content not all
browsers understands in all configurations, or to send gzipped content
which won't be cached by most caches or browsers..

The first "works now" but does not encourage the problem to be fixed in
the correct way as fixing the problem won't help such gzipped content..

The latter "works later" while not causing any corrupion now and
encourages the problem to get fixed the way it should, but gives a
higher load on the content providers server and slower experience by
users until the needed support is there in the infrastructure to the
client..

To tell if this is the problem of your corruption log_mime_hdrs is your
friend. You need to look for the Content-Encoding reply header. If the
corrupted replies has a gzip encoding while the working reply does not
then this is quite likely your problem.

Regards
Henrik

Wei Keong wrote:
>
> Seems like it is due to caching of compressed (mod_gzip) objects, and
you
> did not enable Http 1.1 in the IE browser... tools/internet
options/adv
>
> telnet www.inix.dhs.org 80
> Trying 210.193.6.54...
> Connected to www.inix.dhs.org.
> Escape character is '^]'.
> GET / HTTP/1.0
>
> HTTP/1.1 200 OK
> Date: Tue, 21 Jan 2003 02:06:01 GMT
> Server: Apache/1.3.27 (Unix) (Red-Hat/Linux) AxKit/1.6
mod_gzip/1.3.19.1a
> PHP/4.1.2 mod_perl/1.26
> Last-Modified: Sat, 06 Apr 2002 10:51:47 GMT
> ETag: "12e400-32c-3caed343"
> Accept-Ranges: bytes
> Content-Length: 812
> Connection: close
> Content-Type: text/html
Received on Tue Jan 21 2003 - 06:58:12 MST

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