Re: Design Issue: HEADERS+PRIORITY "MUST be used" for each stream that is created??

Roberto Peon <grmocg@gmail.com> Sat, 27 April 2013 21:44 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 1D60A21F97DD for <ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com>; Sat, 27 Apr 2013 14:44:43 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -10.598
X-Spam-Level:
X-Spam-Status: No, score=-10.598 tagged_above=-999 required=5 tests=[BAYES_00=-2.599, HTML_MESSAGE=0.001, 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 I+93rFvsY672 for <ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com>; Sat, 27 Apr 2013 14:44:42 -0700 (PDT)
Received: from frink.w3.org (frink.w3.org [128.30.52.56]) by ietfa.amsl.com (Postfix) with ESMTP id 55FEC21F97D5 for <httpbisa-archive-bis2Juki@lists.ietf.org>; Sat, 27 Apr 2013 14:44:42 -0700 (PDT)
Received: from lists by frink.w3.org with local (Exim 4.72) (envelope-from <ietf-http-wg-request@listhub.w3.org>) id 1UWCv2-0006h4-60 for ietf-http-wg-dist@listhub.w3.org; Sat, 27 Apr 2013 21:44:32 +0000
Resent-Date: Sat, 27 Apr 2013 21:44:32 +0000
Resent-Message-Id: <E1UWCv2-0006h4-60@frink.w3.org>
Received: from maggie.w3.org ([128.30.52.39]) by frink.w3.org with esmtp (Exim 4.72) (envelope-from <grmocg@gmail.com>) id 1UWCux-0006gO-3t for ietf-http-wg@listhub.w3.org; Sat, 27 Apr 2013 21:44:27 +0000
Received: from mail-oa0-f51.google.com ([209.85.219.51]) by maggie.w3.org with esmtps (TLS1.0:RSA_ARCFOUR_SHA1:16) (Exim 4.72) (envelope-from <grmocg@gmail.com>) id 1UWCuw-0004A1-DM for ietf-http-wg@w3.org; Sat, 27 Apr 2013 21:44:27 +0000
Received: by mail-oa0-f51.google.com with SMTP id k14so5035992oag.10 for <ietf-http-wg@w3.org>; Sat, 27 Apr 2013 14:44:00 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:x-received:in-reply-to:references:date:message-id :subject:from:to:cc:content-type; bh=oXz/HcIlTgufQnBS2tjW8Gv9d4SNG/R3g6o0Opiksmg=; b=v9kEYuF8qxvc3tKtXQmKZWtigsYeSTzp9ZcSaoXrY3UQ2UeqVRwZc1BSTzGu9cFhzC 3hhGSez9h+Z/5LjzfiifiRQwJEb9Yz7Q5Nk4YVfMcAW0SaR/Lxl1R6gbW/pnQpnw+hn1 I+QfG/MdTDNgxZtQvxvBEyysQhAgwt06ytCvWTk169CBKa5NS09IoFGmzeavL+Ps9Pfj ufiWbDdvvHhsH2xmXdIrBJIFSH4jFykBzgLb6ohCXgt/AJNRaZE4HelHz3stDr93V81r MOYGZjsPDcpO6anAWR8XaXA4c1PtqxFo9dNdioSQceTdV4j0uevWfksBLsguM8JqCmj0 1r+A==
MIME-Version: 1.0
X-Received: by 10.60.58.99 with SMTP id p3mr11041281oeq.23.1367099040568; Sat, 27 Apr 2013 14:44:00 -0700 (PDT)
Received: by 10.76.12.103 with HTTP; Sat, 27 Apr 2013 14:44:00 -0700 (PDT)
In-Reply-To: <CABP7RbeEzozvxq4rAeL-+QgyctPxC4cXLC=7gPOYQS0cUqkDcQ@mail.gmail.com>
References: <CABP7Rbe808o_rqxnvVvH6OJxqFSvOnoLgnaQT5goFabBF_zi0A@mail.gmail.com> <CABkgnnUBnr8+_bbFRGMhnWSkGK5N+DoX75m8bHuLfa0Zbq4=CA@mail.gmail.com> <CABP7RbeAb71vTmnGbR65wVepyT=WykdRcRNFYDuWoprWD7+2gg@mail.gmail.com> <CABkgnnW5tDqVwRJE99Fkd5YFeAcRZYPV40QjuBrdrZxbKj6+9w@mail.gmail.com> <CABP7RbeEzozvxq4rAeL-+QgyctPxC4cXLC=7gPOYQS0cUqkDcQ@mail.gmail.com>
Date: Sat, 27 Apr 2013 14:44:00 -0700
Message-ID: <CAP+FsNdNxykDTDNmFrq4JfQDtLhH3Swtx9O3mxXd1PNRz97Eog@mail.gmail.com>
From: Roberto Peon <grmocg@gmail.com>
To: James M Snell <jasnell@gmail.com>
Cc: Martin Thomson <martin.thomson@gmail.com>, "ietf-http-wg@w3.org" <ietf-http-wg@w3.org>
Content-Type: multipart/alternative; boundary=089e013d0758afebd004db5e8cbe
Received-SPF: pass client-ip=209.85.219.51; envelope-from=grmocg@gmail.com; helo=mail-oa0-f51.google.com
X-W3C-Hub-Spam-Status: No, score=-3.5
X-W3C-Hub-Spam-Report: AWL=-2.672, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_FROM=0.001, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_LOW=-0.7, SPF_PASS=-0.001
X-W3C-Scan-Sig: maggie.w3.org 1UWCuw-0004A1-DM c6c3b1f0166981cd715ab9f4da56cc0a
X-Original-To: ietf-http-wg@w3.org
Subject: Re: Design Issue: HEADERS+PRIORITY "MUST be used" for each stream that is created??
Archived-At: <http://www.w3.org/mid/CAP+FsNdNxykDTDNmFrq4JfQDtLhH3Swtx9O3mxXd1PNRz97Eog@mail.gmail.com>
Resent-From: ietf-http-wg@w3.org
X-Mailing-List: <ietf-http-wg@w3.org> archive/latest/17640
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>

The WS case may actually require headers as we do need to announce (per WS
'connection') the URL of the endpoint to which it is attaching/connecting.
-=R


On Fri, Apr 26, 2013 at 1:54 PM, James M Snell <jasnell@gmail.com> wrote:

> Well, until that case is made, we don't have very many good reasons to
> allow DATA frames with preceding headers-bearing frames. Also, keep in
> mind that it's perfectly legal to send a HEADERS frame with an empty
> set of HEADERS. It the WebSockets case does not require any preceding
> headers (which I rather doubt), it would still be simple enough to
> send an empty HEADERS frame to establish the stream before sending the
> DATA frames.
>
>
> On Fri, Apr 26, 2013 at 1:49 PM, Martin Thomson
> <martin.thomson@gmail.com> wrote:
> > On 26 April 2013 13:43, James M Snell <jasnell@gmail.com> wrote:
> >> I think I disagree on that point and say that I think it's much safer
> >> if we require that streams be initiated with only headers-bearing
> >> frames.
> >>
> >> Imagine, for instance, that a sender sends along a DATA frame with a
> >> new, previously unused stream identifier. Without an associated
> >> headers frame I have absolutely no context with which to determine
> >> what I need to do with that DATA frame. Likewise if I receive an
> >> RST_STREAM that references a previously unused stream identifier. If
> >> there's absolutely nothing that I can reliably do with it, or not
> >> reliable way that I can interpret it without additional context, then
> >> we should not allow it.
> >
> > I believe that this is exactly the scenario that the websockets
> > binding will take advantage of.  (Maybe there is some need to expose
> > some header information there, but that's a case that needs to be made
> > for that specific use of the framing layer.)
>
>