Re: WWW Proxy information

burchard@geom.umn.edu
Errors-To: listmaster@www0.cern.ch
Date: Mon, 2 May 1994 01:38:38 +0200
Errors-To: listmaster@www0.cern.ch
Message-id: <9405012336.AA04615@mobius.geom.umn.edu>
Errors-To: listmaster@www0.cern.ch
Reply-To: burchard@geom.umn.edu
Originator: www-talk@info.cern.ch
Sender: www-talk@www0.cern.ch
Precedence: bulk
From: burchard@geom.umn.edu
To: Multiple recipients of list <www-talk@www0.cern.ch>
Subject: Re: WWW Proxy information
X-Listprocessor-Version: 6.0c -- ListProcessor by Anastasios Kotsikonas
altis@ibeam.jf.intel.com (Kevin Altis) writes:
>
> The FORM itself could be cached depending on the settings
> on the proxy server for a site as could the results, but in
> general, the *results* wouldn't be cached because
> results wouldn't have Last-modified or Expires
> meta-information and the default caching time for HTTP
> results without those meta-fields is 0. I'm currently
> experimenting with a default expiration of 15 minutes to
> an hour or so, to see if it makes a difference to users.  


OK, so it sounds like all CGI output really does need to have Expires  
meta-information added in order to be fully compatible with proxying.

What I understand you to be saying is that the proxy server's caching  
behavior is based only on the meta-information fields and on the URL  
-- not including POST query data! -- that generated the page.  And  
that furthermore, lack of meta-information results in  
server-dependent behavior.  Both of these are quite reasonable, but  
imply that every CGI script needs to preemptively expire its output.

Presumably it would be OK to add a fixed date which is guaranteed to  
be in the past, like:
	Expires: Sunday, 01-Jan-00 00:00:00 GMT
Is that right?

--------------------------------------------------------------------
Paul Burchard	<burchard@geom.umn.edu>
``I'm still learning how to count backwards from infinity...''
--------------------------------------------------------------------