Re: #486: Requiring proxies to process warn-date

Mark Nottingham <mnot@mnot.net> Tue, 28 May 2013 05:37 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 416D521F93A6 for <ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com>; Mon, 27 May 2013 22:37:52 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -7.932
X-Spam-Level:
X-Spam-Status: No, score=-7.932 tagged_above=-999 required=5 tests=[AWL=2.667, 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 W-7kJnOP-pJb for <ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com>; Mon, 27 May 2013 22:37:46 -0700 (PDT)
Received: from frink.w3.org (frink.w3.org [128.30.52.56]) by ietfa.amsl.com (Postfix) with ESMTP id 6006C21F9374 for <httpbisa-archive-bis2Juki@lists.ietf.org>; Mon, 27 May 2013 22:37:46 -0700 (PDT)
Received: from lists by frink.w3.org with local (Exim 4.72) (envelope-from <ietf-http-wg-request@listhub.w3.org>) id 1UhCal-000318-SP for ietf-http-wg-dist@listhub.w3.org; Tue, 28 May 2013 05:37:03 +0000
Resent-Date: Tue, 28 May 2013 05:37:03 +0000
Resent-Message-Id: <E1UhCal-000318-SP@frink.w3.org>
Received: from lisa.w3.org ([128.30.52.41]) by frink.w3.org with esmtp (Exim 4.72) (envelope-from <mnot@mnot.net>) id 1UhCaa-000302-DU for ietf-http-wg@listhub.w3.org; Tue, 28 May 2013 05:36:52 +0000
Received: from mxout-07.mxes.net ([216.86.168.182]) by lisa.w3.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.72) (envelope-from <mnot@mnot.net>) id 1UhCaY-0003Q0-C3 for ietf-http-wg@w3.org; Tue, 28 May 2013 05:36:52 +0000
Received: from [192.168.1.80] (unknown [118.209.184.230]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by smtp.mxes.net (Postfix) with ESMTPSA id 9991222E1F3; Tue, 28 May 2013 01:36:28 -0400 (EDT)
Content-Type: text/plain; charset="iso-8859-1"
Mime-Version: 1.0 (Mac OS X Mail 6.3 \(1503\))
From: Mark Nottingham <mnot@mnot.net>
In-Reply-To: <519A4BE8.9070700@measurement-factory.com>
Date: Tue, 28 May 2013 15:36:24 +1000
Cc: "ietf-http-wg@w3.org Group" <ietf-http-wg@w3.org>
Content-Transfer-Encoding: quoted-printable
Message-Id: <845DDED8-04F7-42D0-834A-9F0AD0CAD556@mnot.net>
References: <D528E812-45A0-426F-972F-3F4AC6F8DEA7@mnot.net> <519413CF.7010007@measurement-factory.com> <A73CEF6C-EE77-462C-BA7E-80147A948D31@mnot.net> <51907161-4A59-4225-A61D-414A322DB589@mnot.net> <519A4BE8.9070700@measurement-factory.com>
To: Alex Rousskov <rousskov@measurement-factory.com>
X-Mailer: Apple Mail (2.1503)
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=-3.4
X-W3C-Hub-Spam-Report: AWL=-3.398, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001
X-W3C-Scan-Sig: lisa.w3.org 1UhCaY-0003Q0-C3 565b3512c8db1339b0ebac6f3994e2d4
X-Original-To: ietf-http-wg@w3.org
Subject: Re: #486: Requiring proxies to process warn-date
Archived-At: <http://www.w3.org/mid/845DDED8-04F7-42D0-834A-9F0AD0CAD556@mnot.net>
Resent-From: ietf-http-wg@w3.org
X-Mailing-List: <ietf-http-wg@w3.org> archive/latest/18102
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>

Anyone have strong feelings about this? 

Personally - it seems reasonable to me to shift the overhead for assuring Warning correctness to those consuming it, since practically, they need to anyway today (as intermediaries don't implement this at all, IME).

Cheers,



On 21/05/2013, at 2:14 AM, Alex Rousskov <rousskov@measurement-factory.com> wrote:

> On 05/19/2013 07:36 PM, Mark Nottingham wrote:
>> On 17/05/2013, at 11:40 AM, Mark Nottingham <mnot@mnot.net> wrote:
>> 
>>>>> and the second to be "If a recipient receives...", also removing
>>>>> "forwarding" later down.
>>>> 
>>>> This would not be sufficient because "using" may be interpreted to
>>>> include "forwarding". How about this:
>>>> 
>>>> "A response sender MUST NOT generate warning-value with a warn-date
>>>> different from the Date value in the response. A cache MUST NOT send a
>>>> warning-value with a warn-date different from the Date value in the
>>>> from-cache response. A recipient MUST ignore a warning-value with a
>>>> warn-date different from the Date value in the response."
>>>> 
>>>> Would that cover all important cases without being too restrictive (like
>>>> requiring the cache not to store something when there is no harm in
>>>> storing, only in serving from the cache)?
> 
>>> I think so, although we should remove the first 'response'.
> 
>> Looking at this again:
> 
>>> A cache MUST NOT send a warning-value with a warn-date different from the Date value in the from-cache response.
> 
> 
>> This has the effect of requiring caches to check warning-values in
>> all cached responses; do we still want to require that?
> 
> 
> Good question. I do not know what the use cases behind the original
> MUSTs were, and whether new use cases appeared since then, so I cannot
> answer this question. If there is consensus that policing Warnings by
> intermediaries (including caches) is not needed, then yes, we can remove
> the entire MUST NOT.
> 
> 
> Cheers,
> 
> Alex.
> 
> 

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