interaction of caching with content negotiation, authentication, state, etc

• From: Larry Masinter <masinter@parc.xerox.com>
• Date: Fri, 22 Dec 1995 16:33:33 PST
• To: mogul@pa.dec.com
• Cc: http-wg%cuckoo.hpl.hp.com@hplb.hpl.hp.com
• Message-Id: <95Dec22.163348pst.2733@golden.parc.xerox.com>

I've been on vacation and just got back. I think the interaction of
'content negotiation' and 'caching' can be limited to acknowledging
that:

* the value returned by applying a method to a URI depends on many
of the other headers in the request (including those supplied during
content negotiation, the user agent, etc.)

* the originating server needs to indicate which request headers were
involved in deciding what content to return, even if those request
headers are not replicated in the entity headers of the response

* a cache might legitimately keep around several cached values for the
same method applied to the same URI, and want to apply a
'get-if-different' validator that would request validation of one of
the several cached values.

The same principle for caching applies for content negotiation,
authentication, and state sharing.

Received on Friday, 22 December 1995 16:37:47 UTC