From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net (mout.gmx.net [212.227.15.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 7E13E3B2A4 for ; Sat, 24 Aug 2019 03:59:46 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1566633579; bh=3FEI9Rpdh1comXj4gHrQYUhV0oMkNCKnf86zL8VIim4=; h=X-UI-Sender-Class:Subject:From:In-Reply-To:Date:Cc:References:To; b=OGYqwyqaWLfO6dct/NmjFgF2zM3qwzLezBH8TfqZ7BxrXrqaLXkicFz0XpYm+Wcpa uWeG2kDVQM4aaFe3MTaDpKORbyznSgB3bovFohjj03zxNyTMOK6oM9av0ocqyrG7yA tdo9c/nw2ISlAdIhF4OJqEeSeuVaKSdBUN8owvl0= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from hms-beagle2.lan ([77.180.126.165]) by mail.gmx.com (mrgmx003 [212.227.17.190]) with ESMTPSA (Nemesis) id 0M7pku-1iNFAh0MAC-00vPVy; Sat, 24 Aug 2019 09:59:39 +0200 Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.11\)) From: Sebastian Moeller In-Reply-To: <20190824095453.1a15ca5a@carbon> Date: Sat, 24 Aug 2019 09:59:36 +0200 Cc: Simon Barber , bloat Content-Transfer-Encoding: quoted-printable Message-Id: <36973E7C-0B93-4512-AB0B-917C807E9684@gmx.de> References: <42B8EB6B-5540-46EB-8BB3-81D6239A4D58@superduper.net> <20190824095453.1a15ca5a@carbon> To: Jesper Dangaard Brouer X-Mailer: Apple Mail (2.3445.104.11) X-Provags-ID: V03:K1:R9hNdPhH1aaDnAqQoLcLEgrzYAhgg2aDTdnb+nn6hnaQPAyh9Cq qT42gNCq4SAqH9DReAm96c33W96PHCBeQEnkVXG7/zUhqp9M9WBVnEtveJiwS9b/eStyVQI YMJvhT5kssuZ20v1rEGvhd0wNBp5LHDot5aNcj/PHwQWJBAnstXIhZDcQdFHvPgILXO48TT Ni0ghJtWtQtEcnSjIGpzw== X-Spam-Flag: NO X-UI-Out-Filterresults: notjunk:1;V03:K0:BVbdkWO0oqk=:wIns2QsXiA7Z2uWZieJQuP BWf3QE2wU0SeKgjBhu5N6p/tl+2pyZbmXjybfNmuBa91BF3J4tLLxDX/7QVqYWdTE2LdU6MZT B82f0CgqFfmwBEVPF8X4IpVy/OGeqNE46JeURBJasgVqxMfVafUfrwgxKG7ay7Teqh8Bwgdf+ NTvqIsalZZxdTlWtMbeN98DX1dV+jqApA3WLAWIDCb5jW3WA4T62vtmQkmOhLeg7qYf02wJrx 4acICk2iN46W9/swOm7+sGQv9r4OJpOGXqkWxc2I6J1U0mFq4aFogfMZnSQ4Z+d8Zw7PRBK5c hubPzYxpOpZmx6nUi+xbI9dWi7iodCjsGhwxwKnHhodkM+NHfyg1at4fM8/XWXjq/aySsy2JV PnOufJD5TBb8mdUr+N+t2cB0AsksJx/hI0cwt6VMJi5Nj6DFDkyUe0gGQxUg2Ff4B0X7DO0Yd Vkfkue5jhR2myZeF+Ms+yi3T1vKWxijMkkoBufzLJGUDp88XVds4ljIKAnmPoP/HnOuNeYoXl am5iuBVP92UFSxj3RuK1PApUC9LmHKrNzPAh4hH1cjG3xbUU6o+njMzZBc7i0H2JMi8cp3cYt RudjzkL/4zxM5NLfLrLNmixf4kV6K+1AqCGm+sWuIxANaurUQK34x4ki5qcPjVgyMEDlf2cKU BBA25O5nBdC4mDbweuw1+nfRT2F7S28g+D9Tdg30GJrmC2HIFW9OURHQeWCSOoyVshgIznojw 5SwVcH3oktcoSL6V0zpoQpPSJMApxGHvyxkA5rzCKGAYKBx0AMF1AMbHPYYgB4NVqf3MVOKdl agu9FAJgjUfZniWA5/xmPfNl+FeWvbPzwx6VLX75tfaCaI4cRQjv6BU1EVT5MRi9wvto5xYuf K65nl/AltbhbxYxrdSMXBtRQdoI99LS6IzryU8mDJa/fwbbtRCcARVzlrwS3rxiIkbAXE6zAu LoDBs2FLqjOFHzMOsllwZFk3ZI6BtoaheuztAIiq6qKqAHo1Ex2JSCBLDkHzYNP+AqtfODAf5 3eI8wVCsjCEdtwoAO9WRcIU++/7AwSOiaIF2L9BbhOgBeTSLLeoqR2BWup7Q8U46YbAH/i3rz T00QTrumcp6lZjef9zQPAjDj3yvn3Q5RhFNF5e75stNOzkgkcOBR9FpsfxAq13oQBaLTaMJZX 7mKeicrQpn2YsS/5OYdAVqO6newjAv4HRKKgd4wZ0G38mcCA== Subject: Re: [Bloat] buffer sizing meeting notes X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 24 Aug 2019 07:59:46 -0000 Another nugget from the notes = (http://yuba.stanford.edu/~bspang/buffer-sizing-meeting/notes/): Chuanxiong Guo, Bytedance Talked about buffering in Bytedance=E2=80=99s datacenters. The top of = rack switches have buffers of 12-32MB, and the aggregation switches have = larger buffers of several GB. Were hoping to use ECN to reduce buffers = for aggregation switches, but argued that precise ECN marking on egress = queue length in VoQs is hard. However, Arista and Barefoot said = they=E2=80=99ve fixed this using the packet latency instead of queue = length for ECN. This looks like an argument for fq_codel/cake's use of time instead of = queue length, OR an argument for fq, because in a non-overwhelmed = fq_system the local bucket's queue length should be somewhat stronger = correlated with the sojurn times, than the sojurn time of a packet = though a shared queue, no? Best Regards Sebastian=20 > On Aug 24, 2019, at 09:54, Jesper Dangaard Brouer = wrote: >=20 > On Fri, 23 Aug 2019 10:13:39 -0700 > Simon Barber wrote: >=20 >>> On Aug 23, 2019, at 9:07 AM, Dave Taht wrote: >>>=20 >>> There's some good preso from various representatives in the dc = market here. >>>=20 >>> The p4 stuff, in particular (from barefoot) is looking impressive. >>>=20 >>> http://yuba.stanford.edu/~bspang/buffer-sizing-meeting/ >=20 > I followed the link to the animation of AIMD (Additive > Increase/Multiplicative Decrease), that was really cool! >=20 > https://dabh.github.io/network_animations/ >=20 > --=20 > Best regards, > Jesper Dangaard Brouer > MSc.CS, Principal Kernel Engineer at Red Hat > LinkedIn: http://www.linkedin.com/in/brouer > _______________________________________________ > Bloat mailing list > Bloat@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/bloat