IETF Logo Mail Archive

Re: [tsvwg] draft-kuhn-quic-careful-resume-02: Linux tcp_metrics

Nicolas Kuhn <nicolas.kuhn.ietf@gmail.com> Fri, 27 January 2023 15:06 UTC

Return-Path: <nicolas.kuhn.ietf@gmail.com>
X-Original-To: tsvwg@ietfa.amsl.com
Delivered-To: tsvwg@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 0688BC14CF13 for <tsvwg@ietfa.amsl.com>; Fri, 27 Jan 2023 07:06:05 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.094
X-Spam-Level:
X-Spam-Status: No, score=-2.094 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, HTML_MESSAGE=0.001, RCVD_IN_ZEN_BLOCKED_OPENDNS=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001, URIBL_DBL_BLOCKED_OPENDNS=0.001, URIBL_ZEN_BLOCKED_OPENDNS=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com
Received: from mail.ietf.org ([50.223.129.194]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Rw4yQmffoQ8E for <tsvwg@ietfa.amsl.com>; Fri, 27 Jan 2023 07:06:01 -0800 (PST)
Received: from mail-ot1-x336.google.com (mail-ot1-x336.google.com [IPv6:2607:f8b0:4864:20::336]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 3604BC14E514 for <tsvwg@ietf.org>; Fri, 27 Jan 2023 07:06:01 -0800 (PST)
Received: by mail-ot1-x336.google.com with SMTP id e21-20020a9d5615000000b006884e5dce99so2223245oti.5 for <tsvwg@ietf.org>; Fri, 27 Jan 2023 07:06:01 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=Oe3+RIKd1qMruVi+CRzfwqCmcOTUCIc1PZD4+ozf15U=; b=KXCK9q23XOWdDoutkRWYVWKjeF9KhClmbW+k2mRIn9AT3BjXSMI/eMKccV28ZQfFxv W89DZvq6LAlvuWBWNXs8/0MmGU/3psfKt1jeEkKVg5v702Z/SyVqQHuB5ZFV1S5MEm3C OvIdeOOQJgwzlPpwzsMIM4YJnPxzNOEqb6y/tHHML0DO7Z3rPt7GwR8PQgPDrxaTfYho vKrBUXzDRkQLNkflV9hjR9FPNaEXY1DKrFmQFjDDeQ0Kmwcll6lLMdn5GHG/lDIvlb3j JXSh93h75UJycRToUmzlfi1kSMLRPpRb4ae0SMcgjwNyWyM3eSLaJYHXIMqpPOFCaDES AivQ==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=Oe3+RIKd1qMruVi+CRzfwqCmcOTUCIc1PZD4+ozf15U=; b=UN+fPQgCRb7gAP9geyMNVwg/U8XEKtOkozlW9YCyuiqwWsPhuvY/xfB/66mbO4L0X0 lpZETua/dHl4v+a2Y6GqOUEl/O4CJZ1DRk6DwgTyzGfF6oPDEekVcy9HZTv9xzmotfJi 7/VY6PiSn6nf6YgB3dQQZukLf7Ed/QgrOim8aXnMZhVZb1ej8UPjHdQvOBq6Hd+NdqWu rFpzEL4/yGXO2Tc01Lc1mCVAHfOOkqd8Z7pGkBZCZAFrj1Qniin1FjkoWMAdXSOf0M2w oOo+57tkyKzcKpwpbunKjej9iN4bf31Q+n5LcXxHXhktMlpoP+3ZFCq7nk4oo2Osn++n A2UQ==
X-Gm-Message-State: AO0yUKVPSE62QVqmu7ftDR8aKce5MIy06+vMssmPPjP2Md0EVsn50Yq0 68G4x7dB9/iUZJBvECxyIvdfn9J0HY++PvLL2Xo=
X-Google-Smtp-Source: AK7set/ETHS5tziFGnnEKVk7neXS4TKvHx143JeDy6tVQgMGT0GAncOSLkxiBR1oc0FDb1ll1cL8tb+Pi+AgJuKbmbQ=
X-Received: by 2002:a9d:7491:0:b0:68b:b0b4:2d43 with SMTP id t17-20020a9d7491000000b0068bb0b42d43mr71758otk.127.1674831960171; Fri, 27 Jan 2023 07:06:00 -0800 (PST)
MIME-Version: 1.0
References: <245BEDAD-9E69-4D4D-A669-926EB12D6738@bbc.co.uk> <AF5947E2-6E88-4B1F-9447-1D0F5DEF4042@ifi.uio.no>
In-Reply-To: <AF5947E2-6E88-4B1F-9447-1D0F5DEF4042@ifi.uio.no>
From: Nicolas Kuhn <nicolas.kuhn.ietf@gmail.com>
Date: Fri, 27 Jan 2023 16:05:48 +0100
Message-ID: <CAL0D2oR1E7zeJ4pAbEVo21s10YUhW+rezWFkTCbJnvWUTO3NtQ@mail.gmail.com>
To: Michael Welzl <michawe@ifi.uio.no>
Cc: Piers O'Hanlon <piers.ohanlon@bbc.co.uk>, "tsvwg@ietf.org" <tsvwg@ietf.org>
Content-Type: multipart/alternative; boundary="0000000000000b749e05f340347e"
Archived-At: <https://mailarchive.ietf.org/arch/msg/tsvwg/-4DG9HCSCInainlCbBOk8F6rHfI>
Subject: Re: [tsvwg] draft-kuhn-quic-careful-resume-02: Linux tcp_metrics
X-BeenThere: tsvwg@ietf.org
X-Mailman-Version: 2.1.39
Precedence: list
List-Id: Transport Area Working Group <tsvwg.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/tsvwg>, <mailto:tsvwg-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/tsvwg/>
List-Post: <mailto:tsvwg@ietf.org>
List-Help: <mailto:tsvwg-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/tsvwg>, <mailto:tsvwg-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 27 Jan 2023 15:06:05 -0000

Thanks for the pointer that we have integrated in the upcoming version of
the document :
https://github.com/NicoKos/resume_connection

Cheers,

Nico

On Tue, Nov 8, 2022 at 1:17 PM Michael Welzl <michawe@ifi.uio.no> wrote:

> Some related information, from Jan’21, is also available in RFC 9040,
> specifically at:
>
> https://www.rfc-editor.org/rfc/rfc9040.html#name-implementation-observations
>
> Cheers,
> Michael
>
>
> On Nov 8, 2022, at 8:52 AM, Piers O'Hanlon <piers.ohanlon@bbc.co.uk>
> wrote:
>
> Hi,
>
> As suggested by Gorry in yesterday’s WG meeting I’m posting what I brought
> to the mic.
>
> I wanted to highlight that it would be useful to examine the existing
> related Linux kernel mechanisms which re-use cached metrics for TCP
> connections. I’ve briefly looked at the logic which stores a metric block
> for all connections that finish successfully
> (net/ipv4/tcp_metrics.c:tcp_update_metrics()) which are accessible via the
> `ip` command:
> e.g.
> $ ip tcp_metrics
> 192.168.0.1 age 528954.152sec ssthresh 14 cwnd 15 rtt 14439us rttvar
> 18665us source 10.10.10.3
> …
>
> When a new connection starts metrics are reused according to rules defined
> (net/ipv4/tcp_metrics.c:tcp_init_metrics()).
>
> I understand some of this also happens in other operating systems but I’m
> not aware of the details.
>
> Piers
>
>
>

v2.23.0 | Report a Bug | By Email