Re: [squid-users] "Accept-Encoding" header

Finally, it's clear for me. Thank you very much!

Just one extra-feature: In some cases Proxy may change the HTTP version
during the request/response processing. You might be seen the examples in
rfc2616 with upgrade of HTTP/1.0 to HTTP/1.1. One guy from the mod_perl
mailing list submitted the following downgrading Via mask to me:
"1.1 proxy1.domain1.com:3128 (Squid/2.4.STABLE2), 1.0 PROXY2,
   proxy3.domain3.com:3128 (Oops 1.5.22f1)"
Here we see that Squid received the HTTP/1.1 request and transferred it as
HTTP/1.0 to the following (MS) Proxy.

As far as I understand the logics of proxy, it should make the reverse
protocol transformation for outbound response. Am I right?

If I'm right, the downgrade of protocol version should be safe for content
compression: the content should not be compressed for HTTP/1.0 on httpd
usually. The possible upgrade of the HTTP version seems very unsafe for the
request processing. For example,
MSIE-6.0 could be configured to work HTTP/1.0 for some special reason.
Namely, it could be done by the end-user to disable the content compression
from somewhere. If proxy upgrades HTTP/1.0 to HTTP/1.1, the httpd could be
confused and might send the response compressed. As far as I understand the
Proxy will fail to decompress the response in this case. Fairly, I can take
the Via header into account on httpd (when it was not altered with the
security group mask) and refrain from content compression in case if
HTTP/1.0 has been used somewhere in the path. I'm just wondering, should I
do that, or the better way exists somewhere?

Thanks,
Slava

From: "Henrik Nordstrom" <hno@marasystems.com>

> Now we are talking.
>
> The CVS tag SQUID_1_2_beta21 translates to squid-1.2.beta21.
> squid-1.2.beta is the developmen versions what later become Squid
> version 2, so any Squid version 2 knows about Vary, and Squid version
> 2.5 or later knows how to proper cache Vary objects.
>
> But see also RFC2616 regarding how to make use of Vary when there may
> be HTTP/1.0 caches in the path.
>
> Regards
> Henrik
>
>
> On Sunday 16 June 2002 05:55, Slava Bizyayev wrote:
> > The nearest CVS tag I find in revision 1.274:
> > SQUID_1_2_beta21
> > Is this a correct version mask to be used to identify the first
> > Squid version, safe to transfer compressed content (or underscores
> > should be replaced with dots)?
> >
> > Thanks,
> > Slava
> >
> > From: "Henrik Nordstrom" <hno@marasystems.com>
> >
> > > Any versions of Squid including version 1.272 or later of http.c.
> > >
> > > 1.272 is the CVS revision version number of http.c, not a Squid
> > > version number. If you look in the CVS log of http.c you will see
> > > CVS tags at different CVS version numbers indicating different
> > > versions of Squid.
>
>
Received on Tue Jun 18 2002 - 19:29:48 MDT