[dns-operations] charter, sitefinder, opendns (slashdot today)

Paul Vixie paul at vix.com
Thu Feb 15 23:42:19 UTC 2007


> >     GET http://x.gtld-servers.net/ HTTP/1.0
> >
> >     <QUERY NAME="example.com" CLASS="IN" TYPE="A"></QUERY>
> 
> This form would defeat http-caching, which might, or might
> not, be a bad thing depending on your point of view.

ok so wait just a minute there, buddy.  in RFC 2756 which we (vixie, wessels)
wrote, to be found at http://www.htcp.org/ which you (wessels) are hosting,
we spake thusly:

   1.3.  This document specifies a Hyper Text Caching Protocol (HTCP)
   which permits full request and response headers to be used in cache
   management, ...

   ...

   4.  Cache Headers

   HTCP/0.0 CACHE-HDRS consist of zero or more of the following headers:

   Cache-Vary: <header-name> ...
      The sender of this header has learned that content varies on a set
      of headers different from the set given in the object's Vary:
      header.  Cache-Vary:, if present, overrides the object's Vary:
      header.

   ...

now i'll grant you, HTCP use hasn't exactly blossomed.  but i believe that
any web caching agent who indexes its content only by URI is *broken*, since
many web pages will have the same URI but content that differs according to
things like "what human language did the browser prefer to receive?"



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