Re: Retry-After in UNIX Timestamp instead of HTTP-Date

Wenbo Zhu <wenboz@google.com> Wed, 07 August 2019 17:00 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 564541206CA for <ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com>; Wed, 7 Aug 2019 10:00:05 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -10.299
X-Spam-Level:
X-Spam-Status: No, score=-10.299 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIMWL_WL_MED=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HEADER_FROM_DIFFERENT_DOMAINS=0.201, HTML_MESSAGE=0.001, MAILING_LIST_MULTI=-1, SPF_PASS=-0.001, URIBL_BLOCKED=0.001, USER_IN_DEF_DKIM_WL=-7.5] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=google.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 sQ-Y7AO5Cpli for <ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com>; Wed, 7 Aug 2019 10:00:03 -0700 (PDT)
Received: from frink.w3.org (frink.w3.org [IPv6:2603:400a:ffff:804:801e:34:0:38]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 64CC7120696 for <httpbisa-archive-bis2Juki@lists.ietf.org>; Wed, 7 Aug 2019 09:59:59 -0700 (PDT)
Received: from lists by frink.w3.org with local (Exim 4.89) (envelope-from <ietf-http-wg-request@listhub.w3.org>) id 1hvPFh-0004fA-Ph for ietf-http-wg-dist@listhub.w3.org; Wed, 07 Aug 2019 16:57:29 +0000
Resent-Date: Wed, 07 Aug 2019 16:57:29 +0000
Resent-Message-Id: <E1hvPFh-0004fA-Ph@frink.w3.org>
Received: from titan.w3.org ([2603:400a:ffff:804:801e:34:0:4c]) by frink.w3.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from <wenboz@google.com>) id 1hvPFe-0004eK-T2 for ietf-http-wg@listhub.w3.org; Wed, 07 Aug 2019 16:57:26 +0000
Received: from mail-yw1-xc34.google.com ([2607:f8b0:4864:20::c34]) by titan.w3.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.89) (envelope-from <wenboz@google.com>) id 1hvPFc-0006rE-Ng for ietf-http-wg@w3.org; Wed, 07 Aug 2019 16:57:26 +0000
Received: by mail-yw1-xc34.google.com with SMTP id q128so32708446ywc.1 for <ietf-http-wg@w3.org>; Wed, 07 Aug 2019 09:57:04 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=7koiCH6YxhjUf/0vz6QSFP8DK0W9C2jcw/h0HaZ1pS4=; b=blOm0LQzbCo5D9J8eSyIZPYarjEk2YFkstDGB0T2NpLU870ijzZH7s7ZCZx8Kil9il PcZ42dPaK0Qvt/23ICyhfqiJ04XpMOsuqQ4WgK14MI4RzyiRhlixllnbcCwqR23V+NJI jgCCix/0RqGu3+STW1AZ2JgFzg6CsusVUXGf/taC5a9oUILvoBrFP7opFaHCV6QsMf6X CmUuxm5C74eDBMOugswHmhBXkCtAufaiSi/QfCtKHRiF8iMaLEFItVItsDBw8fiJFBvB FTI9suJThKLvHqbH1/1l69F+hIFBlUSEBAhYlOEhcme8iTFPjv6RMT0tsqW2JhrOjpxL JjvA==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=7koiCH6YxhjUf/0vz6QSFP8DK0W9C2jcw/h0HaZ1pS4=; b=ZHtqQ+ekrAP07XeD0uGztMcZeC6/li2LwEwWB/DlkB9hbnuw0j8c3AUpqfIq4smQ7B ZCOYH2RL9bGYj9IzemAPTWaEDPAu2zE4NEIFk5nUk4SVnU06+6ejVFgUlf0B0/ndI7in sGbU0JJ88vfiDLtk1B6ux0IlV3iBDFcfuv33jVah3jQbEOufynGsvio9WjEyrKSAs98I gzm7SQo+/z/7Gp1bi8ggum7CQRdY/CIGXbfN02kRi9OkWUpW+c/pEwGBojeNYrJ2Dp/T GgtrKYnoUeGrx8fR6xeAE4/3MG221URtwOsZqNKJZQG4ZhzSS5Q86SKx4mymE6nH8twJ Ss5A==
X-Gm-Message-State: APjAAAU1ABa/Xq+HNUk8oCx576og9IEAeoxOTYYmSCm+sxRXOKCqpsMZ 5LF9oQ08uyQ3+yXdcs/SKMYMfQe0mTeW1L+jhVIa3w==
X-Google-Smtp-Source: APXvYqxfq7BzyD4m54GI1VUAkJI6pH2yweXeXNh1QSOQLhbfbmc1k6Nb/BsuQeD32OCzQ20rg7bfTG/SiwO3SMZTSGU=
X-Received: by 2002:a81:f111:: with SMTP id h17mr6629735ywm.36.1565197022325; Wed, 07 Aug 2019 09:57:02 -0700 (PDT)
MIME-Version: 1.0
References: <CAP9qbHXfX9Y7OjfP3gEtxCtDkd1nZwe7B9CK5FY_OeKf1BQX4A@mail.gmail.com> <716beea3-d7f7-4911-18bc-a23fd6b382fc@treenet.co.nz> <CACHSkNqBCvegNCW5-cQPt93M-_RCp+2Cw+grPMn9Kz2jgrPi+Q@mail.gmail.com> <CAD3-0rMY=+HD=d5cW6=-aa3tsV4oXnU39ArDO18XjhWJvQ3Gug@mail.gmail.com> <CACHSkNo+P-43nx4TrGtgiz8QwQx5545=vutTxqKqjKKQV_MgKA@mail.gmail.com> <CAP9qbHVOiQMt552uyz9jcXnSOZ8JM0WAVZzmqKKZ8=4T=QUB9Q@mail.gmail.com>
In-Reply-To: <CAP9qbHVOiQMt552uyz9jcXnSOZ8JM0WAVZzmqKKZ8=4T=QUB9Q@mail.gmail.com>
From: Wenbo Zhu <wenboz@google.com>
Date: Wed, 7 Aug 2019 09:56:49 -0700
Message-ID: <CAD3-0rO1QNDdc4KwyqCFCR1Z9Y1=Xw3dFtXaJPG-CvTDS8HVsg@mail.gmail.com>
To: Roberto Polli <robipolli@gmail.com>
Cc: =?UTF-8?Q?Philipp_Junghann=C3=9F?= <teamhydro55555@gmail.com>, Amos Jeffries <squid3@treenet.co.nz>, HTTP Working Group <ietf-http-wg@w3.org>
Content-Type: multipart/alternative; boundary="0000000000008582d1058f89d46c"
Received-SPF: pass client-ip=2607:f8b0:4864:20::c34; envelope-from=wenboz@google.com; helo=mail-yw1-xc34.google.com
X-W3C-Hub-Spam-Status: No, score=-20.6
X-W3C-Hub-Spam-Report: BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, ENV_AND_HDR_SPF_MATCH=-0.5, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, USER_IN_DEF_DKIM_WL=-7.5, USER_IN_DEF_SPF_WL=-7.5, W3C_AA=-1, W3C_DB=-1, W3C_WL=-1
X-W3C-Scan-Sig: titan.w3.org 1hvPFc-0006rE-Ng d49ef8c05bba98c25afad5ef9220c2c6
X-Original-To: ietf-http-wg@w3.org
Subject: Re: Retry-After in UNIX Timestamp instead of HTTP-Date
Archived-At: <https://www.w3.org/mid/CAD3-0rO1QNDdc4KwyqCFCR1Z9Y1=Xw3dFtXaJPG-CvTDS8HVsg@mail.gmail.com>
Resent-From: ietf-http-wg@w3.org
X-Mailing-List: <ietf-http-wg@w3.org> archive/latest/36942
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: <https://www.w3.org/Mail/>
List-Post: <mailto:ietf-http-wg@w3.org>
List-Unsubscribe: <mailto:ietf-http-wg-request@w3.org?subject=unsubscribe>

On Wed, Aug 7, 2019 at 7:16 AM Roberto Polli <robipolli@gmail.com>; wrote:

> Thanks @all for your replies!
>
> Il giorno mar 6 ago 2019 alle ore 21:03 Philipp Junghannß
> <teamhydro55555@gmail.com>; ha scritto:
> >>> delay in whatever time unit needed is a good Idea,
> >>> [..] without needing to care for DST, leap days/seconds or whatever,
> Agree.
>
> > ... the advantage over the unixtime is that you dont get to deal with
> the Year 2038 problem
> Agree.
>
> Am Mo., 5. Aug. 2019 um 14:06 Uhr schrieb Amos Jeffries <
> squid3@treenet.co.nz>;:
> >> Wenbo Zhu <wenboz@google.com>;:
> >> And it needs to be a float type (32-bit) to support sub-second
> intervals. (also my earlier question on "Prefer: timeout= ...."  ... )
> >Is it really worth telling a client to re-try in less than a second?
> > At those timescales the server can just queue the request and answer
> > when it can.
> I agree with Amos about subsecond precision, as we have network and
> processing
> latency and clock skew.
>
> @wenboz, can you provide some use case where subsecond precision
> can be effectively used?
>
When HTTP is used for server-to-server communication, 1s is a very long
interval. Also, the retried request may not land on the same server
(process) due to load balancing etc so the client retry wait time has
nothing to do with the expected wait time for the server to "recover" (if
this is one of the assumptions).


> As I wrote in
> https://lists.w3.org/Archives/Public/ietf-http-wg/2019JulSep/0201.html
> I'm writing an I-D on RateLimit headers and I'm investigating
> the relations between those headers and Retry-After.
>
Interesting .. and I will certainly have a closer look.

Thanks,
Wenbo


> Thanks for your feedback
> and have a nice day,
> R:
>