W3C home > Mailing lists > Public > http-caching-historical@w3.org > February 1996

Re: backward compatibility of non-cachable headers

From: Shel Kaphan <sjk@amazon.com>
Date: Tue, 20 Feb 1996 08:29:37 -0800
Message-Id: <199602201629.IAA01432@bert.amazon.com>
To: "Roy T. Fielding" <fielding@avron.ICS.UCI.EDU>
Cc: Shel Kaphan <sjk@amazon.com>, http-caching@pa.dec.com, state@xent.w3.org
Roy T. Fielding writes:
 > 
 > >                             The problem is that the reference to "the
 > > request" in the final sentence is unclear:  does it refer to (1) the
 > > request for which the response contains cache-control: max-age=n?  Or
 > > does it refer to (2) "a new request" for that resource?
 > 
 > (2).  I suppose we should add "new" for that sentence to go along with
 > all the other times it is mentioned in that paragragh, but there is
 > no other reasonable interpretation of that feature.
 > 

Right - my interpretation was slanted by what I thought you had said
in earlier discussions on this list, several months ago (something to
the effect of max-age and expires not being redundant, I recall.  But
let's forget it and get on with other things, since we seem to be
agreeing now).

	...

     Since this
 > > functionality appears to be redundant, I am forced to conclude that
 > > this interpretation, too, must not be what Roy intended.
 > 
 > Why?  I've said several times before that the redundancy is NECESSARY
 > because people did not want to calculate the expiration time from a
 > full HTTP-Date and because clock skew made Expires unreliable for
 > short periods.  Expires will still be used because of older caches,
 > but can be ignored by recipients that understand Cache-control.
 > That whole discussion took place on the WG mailing list last summer.
 > 

OK.

That must have been before I started reading this list.  It's not
going to be that useful to dredge up the archives especially since we seem
to be agreeing -- possibly I misinterpreted some previous comments of
yours in coming to the conclusion that you didn't think max-age and
expires in responses were doing essentially the same thing with a
different encoding.
	...

--Shel
Received on Tuesday, 20 February 1996 16:55:55 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 19:55:57 UTC