Re: WGLC issue: P6 - Multiple values in Cache-Control headers

Mark Nottingham <mnot@mnot.net> Wed, 25 April 2012 04:42 UTC

Return-Path: <ietf-http-wg-request@listhub.w3.org>
X-Original-To: ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com
Delivered-To: ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 3BC6C21E8012 for <ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com>; Tue, 24 Apr 2012 21:42:02 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -10.599
X-Spam-Level:
X-Spam-Status: No, score=-10.599 tagged_above=-999 required=5 tests=[BAYES_00=-2.599, RCVD_IN_DNSWL_HI=-8]
Received: from mail.ietf.org ([12.22.58.30]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 5r7ElhMrTgtA for <ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com>; Tue, 24 Apr 2012 21:42:01 -0700 (PDT)
Received: from frink.w3.org (frink.w3.org [128.30.52.56]) by ietfa.amsl.com (Postfix) with ESMTP id C0A6711E8087 for <httpbisa-archive-bis2Juki@lists.ietf.org>; Tue, 24 Apr 2012 21:42:00 -0700 (PDT)
Received: from lists by frink.w3.org with local (Exim 4.69) (envelope-from <ietf-http-wg-request@listhub.w3.org>) id 1SMu0w-0003Yn-DR for ietf-http-wg-dist@listhub.w3.org; Wed, 25 Apr 2012 04:39:38 +0000
Received: from maggie.w3.org ([128.30.52.39]) by frink.w3.org with esmtp (Exim 4.69) (envelope-from <mnot@mnot.net>) id 1SMu0k-0003Sw-Nq for ietf-http-wg@listhub.w3.org; Wed, 25 Apr 2012 04:39:26 +0000
Received: from mxout-07.mxes.net ([216.86.168.182]) by maggie.w3.org with esmtp (Exim 4.72) (envelope-from <mnot@mnot.net>) id 1SMu0h-0001ux-Du for ietf-http-wg@w3.org; Wed, 25 Apr 2012 04:39:24 +0000
Received: from [10.4.229.38] (unknown [69.20.3.135]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by smtp.mxes.net (Postfix) with ESMTPSA id DA2F422E253; Wed, 25 Apr 2012 00:39:00 -0400 (EDT)
Mime-Version: 1.0 (Apple Message framework v1257)
Content-Type: text/plain; charset=us-ascii
From: Mark Nottingham <mnot@mnot.net>
In-Reply-To: <18AB958B-CC87-44B4-9C3A-D0416C318834@niven-jenkins.co.uk>
Date: Wed, 25 Apr 2012 14:38:56 +1000
Cc: "ietf-http-wg@w3.org Group" <ietf-http-wg@w3.org>, John Sullivan <jsullivan@velocix.com>
Content-Transfer-Encoding: quoted-printable
Message-Id: <0611774E-AC7D-4FD7-A3D0-6C888FE99F43@mnot.net>
References: <18AB958B-CC87-44B4-9C3A-D0416C318834@niven-jenkins.co.uk>
To: Ben Niven-Jenkins <ben@niven-jenkins.co.uk>
X-Mailer: Apple Mail (2.1257)
Received-SPF: pass client-ip=216.86.168.182; envelope-from=mnot@mnot.net; helo=mxout-07.mxes.net
X-W3C-Hub-Spam-Status: No, score=-1.9
X-W3C-Hub-Spam-Report: BAYES_00=-1.9, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001
X-W3C-Scan-Sig: maggie.w3.org 1SMu0h-0001ux-Du 11faae20998fef5fb9ec194e1930d8da
X-Original-To: ietf-http-wg@w3.org
Subject: Re: WGLC issue: P6 - Multiple values in Cache-Control headers
Archived-At: <http://www.w3.org/mid/0611774E-AC7D-4FD7-A3D0-6C888FE99F43@mnot.net>
Resent-From: ietf-http-wg@w3.org
X-Mailing-List: <ietf-http-wg@w3.org> archive/latest/13473
X-Loop: ietf-http-wg@w3.org
Resent-Sender: ietf-http-wg-request@w3.org
Precedence: list
List-Id: <ietf-http-wg.w3.org>
List-Help: <http://www.w3.org/Mail/>
List-Post: <mailto:ietf-http-wg@w3.org>
List-Unsubscribe: <mailto:ietf-http-wg-request@w3.org?subject=unsubscribe>
Resent-Message-Id: <E1SMu0w-0003Yn-DR@frink.w3.org>
Resent-Date: Wed, 25 Apr 2012 04:39:38 +0000

No worries, Ben; raised as <http://trac.tools.ietf.org/wg/httpbis/trac/ticket/353>.


On 24/04/2012, at 3:51 AM, Ben Niven-Jenkins wrote:

> Hi,
> 
> Apologies that this mail misses the WG LC deadline, in Velocix we're reviewing all the HTTPBIS documents but we're a little behind, hence the late comments, sorry. (we're still reviewing so might have more comments as we work through the documents)
> 
> In the HTTPBIS documents there are now specific directions for dealing with multiple values within Host or Content-Length headers.
> 
> However, there doesn't appear to be a general conflict resolution
> strategy.
> 
> For example, if there are multiple Expires headers, valid or invalid (but
> assuming at least one valid one), matching or different, which takes precedence? Or must the set be treated invalid? Always?
> 
> If "Cache-Control: max-age=5, max-age=10" is received, what is the expected behaviour?
> 
> Similar concerns apply to other sections: what do multiple ETag or Last-Modified headers mean? Or multiple Content-Range headers (the same as multiple Content-Length headers one would assume).
> 
> Thanks
> Ben
> 
> 

--
Mark Nottingham   http://www.mnot.net/