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Re: httpbis-p6-cache-06 and no-store response directive

From: Henrik Nordstrom <henrik@henriknordstrom.net>
Date: Tue, 16 Jun 2009 23:12:34 +0200
To: yngve@opera.com
Cc: Mark Nottingham <mnot@mnot.net>, "ietf-http-wg@w3.org" <ietf-http-wg@w3.org>
Message-Id: <1245186754.3368.28.camel@localhost.localdomain>
mån 2009-06-15 klockan 16:42 +0200 skrev Yngve Nysaeter Pettersen:

> As I said above: If they made the choice. In many cases I don't think they  
> did more than select a development environment that made the choice for  
> them, based on what is supposed to provide a "revalidate each time the  
> user clicks on a link to this document"-functionality, that is, the same  
> as "Cache-Control: max-age=0" and "no-cache".

All environments I have seen support setting these kind of things if you
care about them, and emit a default "do not cahe this response" header
if the author / site developer using such environment don't care. Most
people who don't care simply do not know, and quite happily try to
accomodate for caching when they learn what it is.

Blaiming the dev environment for emitting a safe low-performance default
cache profile won't get us very far, neither is trying to work around
this in the cache layer. This situation will persist, and any changes we
make to the protocol will only get reflected in those dev environments
using the new names, until the content/site developers gets their acts
together.

This is a case of careless developers making their sites slower than
they need to be, not a specifacion fault, and not causing an error of
any kind, just slow performance due to content author/developer
ignorance, just as the 100 other asoects which makes web content
delivery slower than it need to be and is as frequently ignored by
content developers/authors.

Regarding some of the big sites using this that can only be assumed to
be their choice, quite likely due to browser bugs in dealing with
no-cache or Vary:. Many of these sites uses Cookie based logins or user
identification, with a farily large userbase of "known users" who do get
slightly modified content compared to anonymous readers.

Regards
Henrik
Received on Tuesday, 16 June 2009 21:13:19 GMT

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