Re: ID for Immutable

Leif Hedstrom <leif@ogre.com> Mon, 07 November 2016 21:25 UTC

Return-Path: <ietf-http-wg-request+bounce-httpbisa-archive-bis2juki=lists.ie@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 6923C1295AA for <ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com>; Mon, 7 Nov 2016 13:25:08 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -8.498
X-Spam-Level:
X-Spam-Status: No, score=-8.498 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HEADER_FROM_DIFFERENT_DOMAINS=0.001, RCVD_IN_DNSWL_HI=-5, RP_MATCHES_RCVD=-1.497, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=ogre.com
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id utBbItucx15e for <ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com>; Mon, 7 Nov 2016 13:25:07 -0800 (PST)
Received: from frink.w3.org (frink.w3.org [128.30.52.56]) (using TLSv1.2 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 4BCDB12957C for <httpbisa-archive-bis2Juki@lists.ietf.org>; Mon, 7 Nov 2016 13:25:07 -0800 (PST)
Received: from lists by frink.w3.org with local (Exim 4.80) (envelope-from <ietf-http-wg-request@listhub.w3.org>) id 1c3rLk-0003ky-He for ietf-http-wg-dist@listhub.w3.org; Mon, 07 Nov 2016 21:21:04 +0000
Resent-Date: Mon, 07 Nov 2016 21:21:04 +0000
Resent-Message-Id: <E1c3rLk-0003ky-He@frink.w3.org>
Received: from titan.w3.org ([128.30.52.76]) by frink.w3.org with esmtps (TLS1.2:RSA_AES_128_CBC_SHA1:128) (Exim 4.80) (envelope-from <leif@ogre.com>) id 1c3rLc-0003kD-3L for ietf-http-wg@listhub.w3.org; Mon, 07 Nov 2016 21:20:56 +0000
Received: from cosmo4.ogre.com ([71.6.165.248] helo=cosmo.ogre.com) by titan.w3.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.84_2) (envelope-from <leif@ogre.com>) id 1c3rLW-00068U-4T for ietf-http-wg@w3.org; Mon, 07 Nov 2016 21:20:50 +0000
Received: by cosmo.ogre.com (8.15.2/8.15.2) with ESMTPSA id uA7LKP44031996 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 7 Nov 2016 13:20:26 -0800
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ogre.com; s=03062012; t=1478553627; bh=7cpZf+cVKwhe/GSgG0hpFS5WnHy4ejnCLlIzYFzcgLQ=; h=Subject:From:In-Reply-To:Date:Cc:References:To; b=X+mA2rsO9k6831wo8ywZJqFZcUGZUMJP00SMi7AjgayBCts5bGr+tZvAgx7cyDhA0 5seTUy+DeRuQScq2wfjSe1vQQiSdE5t+KV55uirAauKoEqRCPwRyVvqgdeMNK5dfSE TmAfWULpXjVdld5rrkLu7P82f6o4rUGOkAzu7ndw=
Content-Type: text/plain; charset=utf-8
Mime-Version: 1.0 (Mac OS X Mail 10.0 \(3226\))
From: Leif Hedstrom <leif@ogre.com>
In-Reply-To: <CAOdDvNqam930_0eA1p3yHW+xDdOm0AAMKvVKe6xwNwm1itpRpQ@mail.gmail.com>
Date: Mon, 7 Nov 2016 14:20:25 -0700
Cc: HTTP Working Group <ietf-http-wg@w3.org>
Content-Transfer-Encoding: quoted-printable
Message-Id: <901964AC-3423-4789-934F-3C583214ED85@ogre.com>
References: <CAOdDvNqam930_0eA1p3yHW+xDdOm0AAMKvVKe6xwNwm1itpRpQ@mail.gmail.com>
To: Patrick McManus <pmcmanus@mozilla.com>
X-Mailer: Apple Mail (2.3226)
Received-SPF: pass client-ip=71.6.165.248; envelope-from=leif@ogre.com; helo=cosmo.ogre.com
X-W3C-Hub-Spam-Status: No, score=-6.9
X-W3C-Hub-Spam-Report: AWL=-0.101, BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RP_MATCHES_RCVD=-2.796, SPF_PASS=-0.001, W3C_AA=-1, W3C_WL=-1
X-W3C-Scan-Sig: titan.w3.org 1c3rLW-00068U-4T 3b1409448a5a495ad64ab43425093820
X-Original-To: ietf-http-wg@w3.org
Subject: Re: ID for Immutable
Archived-At: <http://www.w3.org/mid/901964AC-3423-4789-934F-3C583214ED85@ogre.com>
Resent-From: ietf-http-wg@w3.org
X-Mailing-List: <ietf-http-wg@w3.org> archive/latest/32853
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>

> On Oct 26, 2016, at 3:02 PM, Patrick McManus <pmcmanus@mozilla.com> wrote:
> 
> [as individual]
> 
> FYI
> 
> A new version of I-D, draft-mcmanus-immutable-00.txt
> has been successfully submitted by Patrick McManus and posted to the
> IETF repository.


Interesting. Couple of quick thoughts with my proxy-server hat on.

1) Many (most?) reverse proxy servers has features to ignore e.g. Cache-Control: max-age=0, or Cache-Control: no-cache from the clients. Not doing so would really open up some ugly rat holes for cache busting. [See the ATS configs below].

2) As such, this new CC: immutable directive seems geared primarily towards user-agents and possibly for forward proxies?

3) I didn’t read particularly carefully, but would it make sense to specify exactly what headers a proxy would ignore in favor of CC: immutable? I’m thinking in my case, we’d honor a CC: immutable over some of our configuration options [again see below].

For 3), I believe most clients will send something like 

	Cache-Control: no-cache
	Pragma: no-cache

correct when doing a “force” revalidate? I understand that this is UA specific, but if we are going to say something about this for intermediaries, maybe worth pointing this out? If so, what about Cache-Control: max-age=0?

Cheers,

— leif

P.s
Apache Traffic Server settings (defaults):

	CONFIG proxy.config.http.cache.ignore_client_no_cache INT 1
	CONFIG proxy.config.http.cache.ignore_client_cc_max_age INT 1

P.P.s
Yes, we know this violates the RFC :-).