Re: Design Issue: Merge RST_STREAM and GOAWAY into a single ERROR frame type

James M Snell <jasnell@gmail.com> Fri, 03 May 2013 20:55 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 CF5CB21F8AF8 for <ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com>; Fri, 3 May 2013 13:55:15 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -9.729
X-Spam-Level:
X-Spam-Status: No, score=-9.729 tagged_above=-999 required=5 tests=[AWL=0.870, 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 yh3bSGNRTzr7 for <ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com>; Fri, 3 May 2013 13:55:09 -0700 (PDT)
Received: from frink.w3.org (frink.w3.org [128.30.52.56]) by ietfa.amsl.com (Postfix) with ESMTP id 9282D21F8E2C for <httpbisa-archive-bis2Juki@lists.ietf.org>; Fri, 3 May 2013 13:55:09 -0700 (PDT)
Received: from lists by frink.w3.org with local (Exim 4.72) (envelope-from <ietf-http-wg-request@listhub.w3.org>) id 1UYMzo-00008F-Op for ietf-http-wg-dist@listhub.w3.org; Fri, 03 May 2013 20:54:24 +0000
Resent-Date: Fri, 03 May 2013 20:54:24 +0000
Resent-Message-Id: <E1UYMzo-00008F-Op@frink.w3.org>
Received: from maggie.w3.org ([128.30.52.39]) by frink.w3.org with esmtp (Exim 4.72) (envelope-from <jasnell@gmail.com>) id 1UYMzd-00007P-QI for ietf-http-wg@listhub.w3.org; Fri, 03 May 2013 20:54:13 +0000
Received: from mail-ob0-f174.google.com ([209.85.214.174]) by maggie.w3.org with esmtps (TLS1.0:RSA_ARCFOUR_SHA1:16) (Exim 4.72) (envelope-from <jasnell@gmail.com>) id 1UYMzd-0002Bv-7O for ietf-http-wg@w3.org; Fri, 03 May 2013 20:54:13 +0000
Received: by mail-ob0-f174.google.com with SMTP id dn14so1775703obc.19 for <ietf-http-wg@w3.org>; Fri, 03 May 2013 13:53:47 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-received:mime-version:in-reply-to:references:from:date:message-id :subject:to:cc:content-type; bh=MGHDOEokWK6ZmGkvNYKlSYJbsuNRC6adpSxHHOX3Q5M=; b=y5djoNtOwcI7AQpfDzB0UrkqUD9k+0RpW9ruwM3+Gag97810l+ZTUL0BK+BFQ5IZdM QYT4A9CqGyFOGWjOeN2jsIpXEYP/dwKyqOYDh6ZgtZLQBRy5s2P4rDQzXq4aBKUNCc9S 0eQMB2oDWQC/9BP4U+cSttNXUUmH6tsMVs7OL5eNiZUeZHurjhtK1cERHjGQZw9bV/Hu r8FgOGxnbFqOE5QySU3T4O+SFi5e1N0NOTPT7qt4BXyr8sLXjmA3aZtMBq2zlix674aP LMwB2tAZ8qhROuA6yHWRN+YHqUsHHGwpwxGQF2gFaHFCTQ5KGPB2J6GJ72FnQk//s7y8 kEEQ==
X-Received: by 10.60.42.135 with SMTP id o7mr3351700oel.97.1367614427246; Fri, 03 May 2013 13:53:47 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.60.3.137 with HTTP; Fri, 3 May 2013 13:53:27 -0700 (PDT)
In-Reply-To: <CA+pLO_gWErCMv+j3pcmy+cTkt-hh2v6a7neeyDtg7HRN3x=Sgw@mail.gmail.com>
References: <CABP7RbeJm-AKxU3qGxt2tCGrb0xCQL8njNyEToA7Ln9gS8hnTQ@mail.gmail.com> <CA+pLO_gWErCMv+j3pcmy+cTkt-hh2v6a7neeyDtg7HRN3x=Sgw@mail.gmail.com>
From: James M Snell <jasnell@gmail.com>
Date: Fri, 3 May 2013 13:53:27 -0700
Message-ID: <CABP7RbfJEwkMVum0HXei_mqvJ=pHd2G=jx_wz=sZzboi4ZMwzQ@mail.gmail.com>
To: Jeff Pinner <jpinner@twitter.com>
Cc: "ietf-http-wg@w3.org" <ietf-http-wg@w3.org>
Content-Type: text/plain; charset=UTF-8
Received-SPF: pass client-ip=209.85.214.174; envelope-from=jasnell@gmail.com; helo=mail-ob0-f174.google.com
X-W3C-Hub-Spam-Status: No, score=-3.5
X-W3C-Hub-Spam-Report: AWL=-2.665, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_LOW=-0.7, SPF_PASS=-0.001
X-W3C-Scan-Sig: maggie.w3.org 1UYMzd-0002Bv-7O 336569f5527ddf7939fc5de0d24c70e7
X-Original-To: ietf-http-wg@w3.org
Subject: Re: Design Issue: Merge RST_STREAM and GOAWAY into a single ERROR frame type
Archived-At: <http://www.w3.org/mid/CABP7RbfJEwkMVum0HXei_mqvJ=pHd2G=jx_wz=sZzboi4ZMwzQ@mail.gmail.com>
Resent-From: ietf-http-wg@w3.org
X-Mailing-List: <ietf-http-wg@w3.org> archive/latest/17812
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>

Speaking candidly, if we find ourselves requiring more than 8 boolean
flags on an error frame we should all just quit and go home.

On Fri, May 3, 2013 at 1:34 PM, Jeff Pinner <jpinner@twitter.com>; wrote:
> IIRC, when this was brought up at the last F2F the rational for NOT doing
> this was that frame types were cheaper than flags (256 frame types, 8
> flags).
>
> That being said I think we should consider combining them :)
>
>
> On Fri, May 3, 2013 at 1:04 PM, James M Snell <jasnell@gmail.com>; wrote:
>>
>> As a simplification, I'd like to suggest that we merge the RST_STREAM
>> and GOAWAY frames into a single ERROR frame with the following
>> definition:
>>
>>  0                   1                   2                   3
>>  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
>> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>> |                      Error Code (32)                          |
>> +---------------------------------------------------------------+
>> |X|                  Last-Stream-ID (31)                        |
>> +-+-------------------------------------------------------------+
>>
>> (note that this flips the field order from the GOAWAY frame)
>>
>> A frame-specific GOAWAY flag bit (0x2) would be defined for the frame,
>> and the Last-Stream-ID field would only be included in the frame data
>> if this flag was set.
>>
>> This does a couple of things for us:
>>
>> 1. It simplifies the error handling and reduces the number of core frame
>> types.
>> 2. It allows us to terminate a stream and terminate the session in a
>> single frame if necessary
>> 3. It gives us a way of reporting non-terminal session errors
>> (currently RST_STREAM is forbidden to use stream id #0 and GOAWAY is
>> always terminal).
>>
>