From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sonic303-25.consmr.mail.ne1.yahoo.com (sonic303-25.consmr.mail.ne1.yahoo.com [66.163.188.151]) (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 86FE83BA8E for ; Tue, 28 Aug 2018 19:53:11 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rogers.com; s=s2048; t=1535500390; bh=owNqtEKOuwoiBbCZsM/OuTCLjaGR/p0GnpM7wyof0Vc=; h=Reply-To:Subject:To:References:From:Date:In-Reply-To:From:Subject; b=NSU7wEBQz4bsuMR3qkixD2FfkKDWh75+kSe6YCXu1FWu3x0NfeTGJLkeyTMWfkeV+RumN+8UW+bt1Htvfrkr2XDEwz4cLtaVlnUa93w39t/1C/fzq9xy2OX4r/znfL7fNRynwI/OJLbyiMRoChtTJn0muYm5cTRSgJJA71FqcRfQR48VeiRbDUynQkO/pwNwCuin2Y92aWzzHlgOehLf/OALuygJ9dm/ChHSxSjZCSdpWbjs6lvJAG9DcoPITL4CjMYtZzWS9VAoiHj+lFBLcndPquHt5Ye+DGzHRxTC3KHaVz3semTPAsEiSdP8Gg6q1iZHhlwO4Bpgsnh5cRaA7A== X-YMail-OSG: W80e8GQVM1mDalaZFGzuJFfzJEWGMyVjTlC3_yDdfLpqojdHAbLF4VXiM.8mn.c 8fes0ETz8Txv4I1leyOjUDnZCS4SGNVZyy_6OtIV1yZFHoIY_l2DlU.xo_j.A1y39KR8PlLPMtHZ uFtNxgSnKW3wI3vjrXRWXsz8wSTt92G8RydxoXcueMu0QshVx5pUgZRoI3BiG4wg_aVMI0Okct6r RyVk06u3hB.nPfUgpaH_kIinMukz3c8kGrWwL_2URsoNbSnttLRQ9NHrZK478EUhcZagxGHxD0Ic dU0i9S_qvW2XuDW_34SHsgj6oq8UxqygHOZxpeB5J3jdQY31TRhJZHStt.O2YF_MUPAO2hUlt9ys A._iQKvhJcEU6DsFkiTFoZHcgwKjekd7fXaBkU9X6JIGZDsZuZeJfFjcBgym29HhGRM8atbbz2ku bHDa12hGKQOATTCTFhr_deLnBBRGS84rX4X099.8mLb..FSaQ142fBxZX.9322.cq8LaWgIO5FkZ 0LqZydkZiXypk9PfjCyZ9NB6Yj_srHxkgwjfru3_pzyTU6aWV0qvGePOlanRJIjKVE3hMk0T8FnI 3mUDvWdfl80WOLFebzZmgZQDh8lrCsigl6bu9X0S5BfHByiwzXBRPMY46xf0D8J_8VWJLk8SUurq QckTCC4wvtA.KZCfQvvfBto2dlCmGvxFIJEB4vDZKeRm2jjdFLM0MN8IWmSpS0BFLiZx1XTCiNWx np.fLfDSxznqtEzZO8kIbyGCOzwHzRTfGu1s9cr8O2LRTxizQ4eic9NeojGMbjSJ.f1H1UmF_o04 lbUXbFYihNG8iesNfzjdFNu6s._lbIT.2xZxc2uURGpj8f_NrOpUsdrhNUJxZEe3r13JpXpqvCSJ 7Bo4MN9J5s6zV_dHM4KkmhqL6lzRVkaEZizR54w.rf9XZgMooOU4EdPphfqcHBMXuOQzqPN_K23T C8HU3sgJrkyrrBNPQUW5UfNw1GkI2r0bVfIkDwG.n3BN_.UXbH4l0G1gfvcLUcmA7Rx2HaljEwao MVa.kcvJJ37jAw3lcFeSTicI- Received: from sonic.gate.mail.ne1.yahoo.com by sonic303.consmr.mail.ne1.yahoo.com with HTTP; Tue, 28 Aug 2018 23:53:10 +0000 Received: from CPEbc4dfba21363-CMbc4dfba21360.cpe.net.cable.rogers.com (EHLO [192.168.0.11]) ([99.242.215.211]) by smtp426.mail.ne1.yahoo.com (Oath Hermes SMTP Server) with ESMTPA ID 9f49e2f51825f152c4c81624cde49ee0; Tue, 28 Aug 2018 23:53:08 +0000 (UTC) Reply-To: davecb@spamcop.net To: bloat@lists.bufferbloat.net References: From: David Collier-Brown Message-ID: <2385fcbb-d460-ce57-e4e3-e3cbb94ebc3d@rogers.com> Date: Tue, 28 Aug 2018 19:53:07 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Subject: Re: [Bloat] an observation from the field 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: Tue, 28 Aug 2018 23:53:11 -0000 On 2018-08-28 1:07 p.m., Dave Taht wrote: > In looking over the increasingly vast sqm-related deployment, there's > a persistent data point that pops up regarding inbound shaping at high > rates. > > We give users a choice - run out of cpu at those rates or do inbound > sqm at a rate their cpu can afford. A remarkable percentage are > willing to give up tons of bandwidth in order to avoid latency > excursions (oft measured, even in these higher speed 200+Mbit > deployments, in the 100s of ms) - Humans experience delays directly, and so perceive systems with high latency as "slow". The proverbial "man on the Clapham omnibus" therefor responds to high-latency systems with disgust. A trained scientist, however, runs the risk of choosing something that requires complicated measurement schemes, and might well choose to optimize for throughput, as that sounds like a desirable measure, one matching their intuitions of what "fast" means. Alas, in this case the scientist's intuition is far poorer than the random person's direct experience. > At least some users want low delay always. It's just the theorists > that want high utilization right at the edge of capacity. Users are > forgiving about running out of cpu - disgruntled, but forgiving. > > Certainly I'm back at the point of recommending tbf+fq_codel for > inbound shaping at higher rates - and looking at restoring the high > speed version of cake - and I keep thinking a better policer is > feasible. > My advice to engineers? First, go for things you can both experience and measure, and only then things you have to measure. --dave -- David Collier-Brown, | Always do right. This will gratify System Programmer and Author | some people and astonish the rest davecb@spamcop.net | -- Mark Twain