Re: [quicwg/base-drafts] Flow Control Tuning (#3216)

ianswett <notifications@github.com> Mon, 02 December 2019 17:43 UTC

Return-Path: <noreply@github.com>
X-Original-To: quic-issues@ietfa.amsl.com
Delivered-To: quic-issues@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id C5BC012009C for <quic-issues@ietfa.amsl.com>; Mon, 2 Dec 2019 09:43:39 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -6.382
X-Spam-Level:
X-Spam-Status: No, score=-6.382 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HTML_IMAGE_ONLY_24=1.618, HTML_MESSAGE=0.001, MAILING_LIST_MULTI=-1, RCVD_IN_DNSWL_HI=-5, SPF_HELO_NONE=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=github.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 x7noXAmlj6DA for <quic-issues@ietfa.amsl.com>; Mon, 2 Dec 2019 09:43:38 -0800 (PST)
Received: from out-19.smtp.github.com (out-19.smtp.github.com [192.30.252.202]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 1841812003E for <quic-issues@ietf.org>; Mon, 2 Dec 2019 09:43:38 -0800 (PST)
Date: Mon, 02 Dec 2019 09:43:37 -0800
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=github.com; s=pf2014; t=1575308617; bh=xyrTSbK0RWs+gTxnc0oWG7/1EuVrxkrGy0xi4hEgbcQ=; h=Date:From:Reply-To:To:Cc:In-Reply-To:References:Subject:List-ID: List-Archive:List-Post:List-Unsubscribe:From; b=JPBGTszx6JvMSHvjQD3DZbhAFPnGBWKfWkvBBsUmTpYobFHRwmS/gK2KOVpL6Lj4R JQd1oj52woWEqTFg07Ndo7bOmZgQQG+w4/lJTMxxRtXcj8gpMHlfuNivbWfvHlZEi2 tYWXlk85HVZahRjy4JDWjQIarRPHaBcRjxjmfxF8=
From: ianswett <notifications@github.com>
Reply-To: quicwg/base-drafts <reply+AFTOJKZJADMRDKONKYHZBXN36J74TEVBNHHB6D3C4A@reply.github.com>
To: quicwg/base-drafts <base-drafts@noreply.github.com>
Cc: Subscribed <subscribed@noreply.github.com>
Message-ID: <quicwg/base-drafts/issues/3216/560502012@github.com>
In-Reply-To: <quicwg/base-drafts/issues/3216@github.com>
References: <quicwg/base-drafts/issues/3216@github.com>
Subject: Re: [quicwg/base-drafts] Flow Control Tuning (#3216)
Mime-Version: 1.0
Content-Type: multipart/alternative; boundary="--==_mimepart_5de54d493cd98_12833f8f37acd96424502c"; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: list
X-GitHub-Sender: ianswett
X-GitHub-Recipient: quic-issues
X-GitHub-Reason: subscribed
X-Auto-Response-Suppress: All
X-GitHub-Recipient-Address: quic-issues@ietf.org
Archived-At: <https://mailarchive.ietf.org/arch/msg/quic-issues/ne4Rj8gTdgrixPgftJDFgFJ8fE4>
X-BeenThere: quic-issues@ietf.org
X-Mailman-Version: 2.1.29
List-Id: Notification list for GitHub issues related to the QUIC WG <quic-issues.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/quic-issues>, <mailto:quic-issues-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/quic-issues/>
List-Post: <mailto:quic-issues@ietf.org>
List-Help: <mailto:quic-issues-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/quic-issues>, <mailto:quic-issues-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 02 Dec 2019 17:43:40 -0000

I think we should keep this in transport.  

I think we can provide more specific guidance than we do now, including guidance to bundle flow control updates with ACK frames, but not to bundle them with every ACK frame(otherwise you end up ACK-ing ACKs, which we know is bad).  I'm biased towards marking this editorial, but we can wait for a PR to see.

Our implementation does(approximately):
1) Send an update every time 1/2 the window has been consumed
2) Double the size of the window every time two updates are sent within an RTT.

Particularly early in the connection, ideally the flow control window is 2x the peer's current congestion control window, because the CWND doubles every RTT in slow start.

-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/quicwg/base-drafts/issues/3216#issuecomment-560502012