Re: WWW Proxy information

burchard@geom.umn.edu
Sun, 1 May 94 18:36:35 -0500

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?

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