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 A10927AD for ; Thu, 23 Jul 2015 19:57:50 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-wi0-f175.google.com (mail-wi0-f175.google.com [209.85.212.175]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 95C5E14F for ; Thu, 23 Jul 2015 19:57:49 +0000 (UTC) Received: by wibud3 with SMTP id ud3so38999677wib.1 for ; Thu, 23 Jul 2015 12:57:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-type; bh=WlAstQyOHA7iY5BVgwqdSG0ciTaE2TRM+ANUM7vT+wQ=; b=JcKtSCnJAfsNESqrqRxYnyoZtON3yagCW2Fx14kahSYk6YL+f9jwEKjEesXBBlL2vW n9gBd9GDmkQa0KcZwzuKZIKbmZfjCWUafdr8CF/jvqnBkyFn8QA6IYeO7fOPBqUMva0M akTYzz3VYGpbX5HMZCJf31udjmq+sUQL7XgDREKfe+20l8f24vgnE7OHAqSSdpwTEMtP YDF7w0LRV2AzM3rTEeZhmGHT3p2bbhALlYrnCN7lKLiRBI9AZZYdmehlK4+cEZDldt1z zk64FI6fsJbyl5nMdhmKU7p5PlR3gr8WDCzJQEBD0yVYYpFdel6PqoeE5Il0k+9VTWX3 4FAQ== X-Received: by 10.194.246.105 with SMTP id xv9mr19124702wjc.135.1437681468467; Thu, 23 Jul 2015 12:57:48 -0700 (PDT) MIME-Version: 1.0 References: <25607701-D3ED-4D0D-A5B3-C02B727671BF@petertodd.org> In-Reply-To: From: =?UTF-8?B?Sm9zZXBoIEdsZWFzb24g4pGI?= Date: Thu, 23 Jul 2015 19:57:38 +0000 Message-ID: To: Marcel Jamin , Peter Todd Content-Type: multipart/alternative; boundary=001a11c3a5363a703d051b904d42 X-Spam-Status: No, score=-2.7 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,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 19:57:50 -0000 --001a11c3a5363a703d051b904d42 Content-Type: text/plain; charset=UTF-8 That is how I read it as well. On Thu, Jul 23, 2015 at 12:56 PM Marcel Jamin via bitcoin-dev < bitcoin-dev@lists.linuxfoundation.org> wrote: > 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 >> > > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev > --001a11c3a5363a703d051b904d42 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
That is how I read it as well.


On Thu, Jul 23, 2015 at 12:56 PM M= arcel Jamin via bitcoin-dev <bitcoin-dev@lists.linuxfoundation.org> wrote:
He measured the upload cap= acity 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 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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