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 94A9AC7B for ; Sun, 30 Aug 2015 02:35:13 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from mail.bluematt.me (mail.bluematt.me [192.241.179.72]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id A8EE6A8 for ; Sun, 30 Aug 2015 02:35:12 +0000 (UTC) Received: from [172.17.0.2] (gw.vpn.bluematt.me [162.243.132.6]) by mail.bluematt.me (Postfix) with ESMTPSA id 8632357BB1; Sun, 30 Aug 2015 02:35:11 +0000 (UTC) To: Peter R References: <55E21F2E.9000308@mattcorallo.com> <786493BB-2136-4587-A309-B8B1A34ED568@gmx.com> <55E26B82.2070805@mattcorallo.com> From: Matt Corallo Message-ID: <55E26BDE.2080607@mattcorallo.com> Date: Sun, 30 Aug 2015 02:35:10 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.1.0 MIME-Version: 1.0 In-Reply-To: <55E26B82.2070805@mattcorallo.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Cc: bitcoin-dev@lists.linuxfoundation.org, Daniele Pinna Subject: Re: [bitcoin-dev] On the Nature of Miner Advantages in Uncapped Block Size Fee Markets 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: Sun, 30 Aug 2015 02:35:13 -0000 Of course this assumes the network does not change any as a result of such a system. But such a system provides strong incentives for the network to centralize in other ways (put all the mining nodes in one DC for all miners, etc). Matt On 08/30/15 02:33, Matt Corallo via bitcoin-dev wrote: > It is not a purely academic scenario that blocks contain effectively no > information (that was not previously relayed). I'm not aware of any > public code to do so, but I know several large miners who pre-relay the > block(s) they are working on to other nodes of theirs around the globe. > This means at announce-time you have only a few bytes to broadcast (way > less than a packet, and effects of using smaller packets to relay things > vs larger packets are very small, if anything). After you've broadcast > to all of your nodes, hops to other mining nodes are probably only a > handful of ms away with very low packet loss, so relay time is no longer > connected to transaction inclusion at all (unless you're talking about > multi-GB blocks). Of course, this is relay time for large miners who can > invest time and money to build such systems. Small miners are completely > screwed in such a system. > > Thus, the orphan risk for including a transaction is related to the > validation time (which is only DB modify-utxo-set time, essentially, > which maybe you can optimize much of that away, too, and only have to > pass over mempool or so). Anyway, my point, really, is that though > miners will have an incentive to not include transactions which will > trigger validation by other nodes (ie things not already in their > mempool), the incentive to not include transactions which have already > been relayed around sufficiently is, while not theoretically zero, as > near to zero in practice as you can get. > > Matt > > On 08/29/15 23:17, Peter R wrote: >> Hello Matt and Daniele, >> >>> this seems to ignore the effects of transaction validation caches and >>> *block >>> compression protocols. * >> >> The effect of block compression protocols is included. This is what I >> call the "coding gain" and use the Greek letter "gamma" to represent. >> >> As long as the block solution announcements contain information (i.e., >> Shannon Entropy) about the transactions included in a block, then the >> fee market will be "healthy" according to the definitions given in the >> linked paper (see below). This is the case right now, this is the case >> with your relay network, and this would be the case using any >> implementation of IBLTs that I can imagine, so long as miners can still >> construct blocks according to their own volition. The "healthy fee >> market" result follows from the Shannon-Hartley theorem; the SH-theorem >> describes the maximum rate at which information (Shannon Entropy) can be >> transmitted over a physical communication channel. >> >> https://dl.dropboxusercontent.com/u/43331625/feemarket.pdf >> >> I've exchanged emails with Greg Maxwell about (what IMO is) an academic >> scenario where the block solutions announcements contain *no information >> at all* about the transactions included in the blocks. Although the fee >> market would not be healthy in such a scenario, it is my feeling that >> this also requires miners to relinquish their ability to construct >> blocks according to their own volition (i.e., the system would already >> be centralized). I look forward to a white paper demonstrating otherwise! >> >> Best regards, >> Peter >> >> >> >> On 2015-08-29, at 2:07 PM, Matt Corallo via bitcoin-dev >> > > wrote: >> >>> I believe it was pointed out previously in the discussion of the Peter R >>> paper, but I'll repeat it here so that its visible - this seems to >>> ignore the effects of transaction validation caches and block >>> compression protocols. Many large miners already have their own network >>> to relay blocks around the globe with only a few bytes on the wire at >>> block-time, and there is also the bitcoinrelaynetwork.org >>> network, which >>> does the same for smaller miners, albeit with slightly less efficiency. >>> Also, transaction validation time upon receiving a block can be rather >>> easily made negligible (ie the only validation time you should have is >>> the DB modify-utxo-set time). Thus, the increased orphan risk for >>> including a transaction can be reduced to a very, very tiny amount, >>> making the optimal blocksize, essentially, including everything that >>> you're confident is in the mempool of other reasonably large miners. >>> >>> Matt >>> >>> On 08/29/15 16:43, Daniele Pinna via bitcoin-dev wrote: >>>> I'd like to submit this paper to the dev-list which analyzes how miner >>>> advantages scale with network and mempool properties in a scenario of >>>> uncapped block sizes. The work proceeds, in a sense, from where Peter >>>> R's work left off correcting a mistake and addressing the critiques made >>>> by the community to his work. >>>> >>>> The main result of the work is a detailed analysis of mining advantages >>>> (defined as the added profit per unit of hash) as a function of miner >>>> hashrate. In it, I show how large block subsidies (or better, low >>>> mempool fees-to-subsidy ratios) incentivize the pooling of large >>>> hashrates due to the steady increasing of marginal profits as hashrates >>>> grow. >>>> >>>> The paper also shows that part of the large advantage the large miners >>>> have today is due to there being a barrier to entry into a >>>> high-efficiency mining class which has access to expected profits an >>>> order of magnitude larger than everyone else. As block subsidies >>>> decrease, this high-efficiency class is expected to vanish leading to a >>>> marginal profit structure which decreases as a function of hashrate. >>>> >>>> This work has vacuumed my entire life for the past two weeks leading me >>>> to lag behind on a lot of work. I apologize for typos which I may not >>>> have seen. I stand by for any comments the community may have and look >>>> forward to reigniting consideration of a block size scaling proposal >>>> (BIP101) which, due to the XT fork drama, I believe has been placed >>>> hastily and undeservedly on the chopping block. >>>> >>>> https://www.scribd.com/doc/276849939/On-the-Nature-of-Miner-Advantages-in-Uncapped-Block-Size-Fee-Markets >>>> >>>> >>>> Regards, >>>> Daniele >>>> >>>> >>>> _______________________________________________ >>>> 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 >> > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev >