[10346] in www-talk@info.cern.ch

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Re: If-Modified-Since No Longer Cool?

daemon@ATHENA.MIT.EDU (Roy T. Fielding)
Mon Oct 7 18:05:29 1996

To: "John W. James" <jjames@firstfloor.com>
Cc: www-talk@w3.org
In-Reply-To: Your message of "Mon, 07 Oct 1996 11:57:32 PDT."
             <2.2.32.19961007185732.007192f0@homeplate> 
Date: Mon, 07 Oct 1996 13:52:10 -0700
From: "Roy T. Fielding" <fielding@liege.ICS.UCI.EDU>
Resent-From: www-talk@w3.org

> I've been noticing with increasing frequency that the commercial servers
> don't appear to be honoring If-Modified-Since in GET requests, and I'm a bit
> baffled as to why. I've checked this against Netscape 2.0, Oracle's
> InfoServer (right name?), and WebSite 1.1.1c, and experimented using telnet
> to port 80 and comparing HEAD replies with GET reply results.

Did the pages you requested have last-modified dates?  A lot of sites
that use commercial servers also do stupid things like make their
home page a cgi script, or use non-static server-side includes
and automated footers and a host of other cache-unfriendly mechanisms.

As far as I know, server developers haven't given up on IMS.  They
would be fools to do so, since it would lead to higher server load
and reduced capacity for simultaneous connections.

 ...Roy T. Fielding
    Department of Information & Computer Science    (fielding@ics.uci.edu)
    University of California, Irvine, CA 92697-3425    fax:+1(714)824-4056
    http://www.ics.uci.edu/~fielding/


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