From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 44DF67AD for ; Thu, 23 Jul 2015 19:56:38 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-yk0-f174.google.com (mail-yk0-f174.google.com [209.85.160.174]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 9700614F for ; Thu, 23 Jul 2015 19:56:37 +0000 (UTC) Received: by ykay190 with SMTP id y190so2505169yka.3 for ; Thu, 23 Jul 2015 12:56:37 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc:content-type; bh=AICfTSUARUEcoire4r/lBVSxyujYg4pmOc1HseWNqg8=; b=En1NCpqQQZ5/eolxQspGWBvYCodk6ukEPZhjiZwyZ8ta4vJo+4BY4RqzSaPPLMCa4N nblUZeLwBAdqI2Ih1Za8ItEUELfb6iVxnyq/r2AcuKnNcKHJXc7Dt597czQERU3eNceU mqbl9BaTt/ZilDTP4tVPMtCrlYO8+nvoRaTAP6I2vOLOOpp5kgXhH37N09KohDG/cZ8Z aMNXH2yoWPuZ3mRhGuGb7JAYvqQiD5+0INeQk4Ofh5CHi1Y7L1M003qcMbqUieinGNzB 4E95Vc5yBB0hjRhfOWONMLhIa1svbfyz52E+Usy0AcLlVwZFIfDbpkulaKqYhnLQgsSy 7u4Q== X-Gm-Message-State: ALoCoQn2SrunMEPb7TAsjSkmb4Ndd+UDaJ3qBAzWjj+5NEdAsVyVoyLFLASmDC3TVDXd2CJzxZTs MIME-Version: 1.0 X-Received: by 10.129.44.136 with SMTP id s130mr10365271yws.80.1437681396874; Thu, 23 Jul 2015 12:56:36 -0700 (PDT) Received: by 10.13.224.69 with HTTP; Thu, 23 Jul 2015 12:56:36 -0700 (PDT) In-Reply-To: <25607701-D3ED-4D0D-A5B3-C02B727671BF@petertodd.org> References: <25607701-D3ED-4D0D-A5B3-C02B727671BF@petertodd.org> Date: Thu, 23 Jul 2015 21:56:36 +0200 Message-ID: From: Marcel Jamin To: Peter Todd Content-Type: multipart/alternative; boundary=001a1141e5f2f63297051b904820 X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,HTML_MESSAGE, RCVD_IN_DNSWL_LOW autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Cc: slurms--- via bitcoin-dev Subject: Re: [bitcoin-dev] Bitcoin Node Speed Test X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Development Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 23 Jul 2015 19:56:38 -0000 --001a1141e5f2f63297051b904820 Content-Type: text/plain; charset=UTF-8 He measured the upload capacity of the peers by downloading from them, or am I being dumb? :) 2015-07-23 18:05 GMT+02:00 Peter Todd via bitcoin-dev < bitcoin-dev@lists.linuxfoundation.org>: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA256 > > > > On 23 July 2015 10:19:59 GMT-04:00, slurms--- via bitcoin-dev < > bitcoin-dev@lists.linuxfoundation.org> wrote: > >This does not support the theory that the network has the available > >bandwidth for increased block sizes, as in its current state 37% of > >nodes would fail to upload a 20MB block to a single peer in under 20 > >seconds (referencing a number quoted by Gavin). If the bar for > >suitability is placed at taking only 1% of the block time (6 seconds) > >to upload one block to one peer, then 69% of the network fails for 20MB > >blocks. For comparison, only 10% fail this metric for 1MB blocks. > > Note how due to bandwidth being generally asymetric your findings are > probably optimistic - you've measured download capacity. On top of that > upload is further reduced by the fact that multiple peers at once need to > be sent blocks for reliability. > > Secondly you're measuring a network that isn't under attack - we need > significant additional margin to resist attack as performance is > consensus-critical. > > -----BEGIN PGP SIGNATURE----- > > iQE9BAEBCAAnIBxQZXRlciBUb2RkIDxwZXRlQHBldGVydG9kZC5vcmc+BQJVsRCj > AAoJEMCF8hzn9Lnc47AIAIQbznavjd2Rbqxeq5a3GLqeYoI4BZIQYqfWky+6OQtq > yGRKaqPtGuES5y9L0k7efivT385mOl87PWnWMy61xxZ9FJgoS+YHkEx8K4tfgfA2 > yLOKzeFSar2ROCcjHYyPWa2XXjRbNmiLzfNuQyIBArg/Ch9//iXUUM+GG0mChF5k > nUxLstXgXDNh5H8xkHeLi4lEbt9HFiwcZnT1Tzeo2dvVTujrtyNb/zEhNZScMXDc > UOlT8rBLxzHlytKdXt1GNKIq0feTRJNbreBh7/EB4nYTT54CItaaVXul0LdHd5/2 > kgKtdbUdeyaRUKrKcvxiuIwclyoOuRQp0DZThsB262o= > =tBUM > -----END PGP SIGNATURE----- > > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev > --001a1141e5f2f63297051b904820 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
He measured the upload capacity of the peers by downloadin= g from them, or am I being dumb? :)


=
2015-07-23 18:05 GMT+02:00 Peter Todd via bitcoi= n-dev <bitcoin-dev@lists.linuxfoundation.org>:
-----BEGIN PGP SIGNED MESSAGE-----=
Hash: SHA256



On 23 July 2015 10:19:59 GMT-04:00, slurms--- via bitcoin-dev <bitcoin-dev@lists.linuxfo= undation.org> wrote:
>This does not support the theory that the network has the available
>bandwidth for increased block sizes, as in its current state 37% of
>nodes would fail to upload a 20MB block to a single peer in under 20 >seconds (referencing a number quoted by Gavin). If the bar for
>suitability is placed at taking only 1% of the block time (6 seconds) >to upload one block to one peer, then 69% of the network fails for 20MB=
>blocks. For comparison, only 10% fail this metric for 1MB blocks.

Note how due to bandwidth being generally asymetric your findings ar= e probably optimistic - you've measured download capacity. On top of th= at upload is further reduced by the fact that multiple peers at once need t= o be sent blocks for reliability.

Secondly you're measuring a network that isn't under attack - we ne= ed significant additional margin to resist attack as performance is consens= us-critical.

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