Re: [bitcoin-dev] Miners are struggling with blocks far smaller than 750KB blocks and resorting to SPV mining

From: Luv Khemani <luvb@hotmail•com>
To: "jl2012@xbt•hk" <jl2012@xbt•hk>
Cc: "bitcoin-dev@lists•linuxfoundation.org"
	<bitcoin-dev@lists•linuxfoundation.org>
Subject: Re: [bitcoin-dev] Miners are struggling with blocks far smaller than 750KB blocks and resorting to SPV mining
Date: Mon, 17 Aug 2015 19:18:08 +0800	[thread overview]
Message-ID: <BLU172-W5116800DA6F1409CB7279BC2790@phx.gbl> (raw)
In-Reply-To: <239f3c2d796a1abf337d9a4228e19e26@xbt.hk>

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It could be laziness but i doubt it, especially when the business is so competitive and margins ever shrinking.Half a million dollars in revenue mean little if your running costs are also in the same region.
Also apologies for the bad formatting, outlook must have screwed it up.
EmptyBlock /Time since previous block/ Size of previous block(bytes)/Mined by====================================================370165 29s 720784 Antpool370160 31s 50129 BTCChinaPool370076 49s 469988 F2Pool370059 34s 110994 Antpool370057 73s 131603 Antpool

> Date: Mon, 17 Aug 2015 05:15:15 -0400
> From: jl2012@xbt•hk
> To: luvb@hotmail•com
> CC: bitcoin-dev@lists•linuxfoundation.org
> Subject: Re: [bitcoin-dev] Miners are struggling with blocks far smaller than 750KB blocks and resorting to SPV mining
> 
> The traffic between the pool server and individual hashers is far busier 
> than 50kB/30s. If their bandwidth is so limited, hashers would have 
> switched to other pools already.
> 
> All these data may prove is they have very bad mining codes. For 
> example, their hashers may not be required to update the transaction 
> list regularly. I don't think they are struggling. They are just too 
> lazy or think that's too risky to improve their code. After all, they 
> are generating half million USD per day and a few seconds of downtime 
> would hurt.
> 
> By the way, vast majority of the full blocks (>0.99MB) on the blockchain 
> are generated by Chinese pools.
> 
> Luv Khemani via bitcoin-dev ì¶ 2015-08-17 04:42 Œ‘µ½:
> > Hi all,
> > 
> >  I previously mentioned in a post that i believe that technically
> > nodes are capable of handling blocks an order of magnitude larger than
> > the current blocksize limit, the only missing thing was an incentive
> > to run them. I have been monitoring the blockchain for the past couple
> > of weeks and am seeing that even miners who have all the incentives
> > are for whatever reason struggling to download and validate much
> > smaller blocks.
> > 
> > The data actually paints a very grim picture of the current
> > bandwidth/validating capacity of the global mining network.
> > 
> > See the following empty blocks mined despite a non-trivial elapsed
> > time from the previous block just from the past couple of days alone
> > (Data from insight.bitpay.com):
> > 
> > EmptyBlock /Time since previous block/ Size of previous
> > block(bytes)/Mined by
> > ====================================================370165 29s 720784
> > Antpool
> > 370160 31s 50129 BTCChinaPool
> > 370076 49s 469988 F2Pool
> > 370059 34s 110994 Antpool
> > 370057 73s 131603 Antpool
> > 
> > We have preceding blocks as small as 50KB with 30s passing and the
> > miner continues to mine empty blocks via SPV mining.
> > The most glaring case is Block 370057 where despite 73s elapsing and
> > the preceding block being a mere 131KB, the miner is unable to
> > download/validate fast enough to include transactions in his block.
> > Unless ofcourse the miner is mining empty blocks on purpose, which
> > does not make sense as all of these pools do mine blocks with
> > transactions when the elapsed time is greater.
> > 
> > This is a cause for great concern, because if miners are SPV mining
> > for a whole minute for <750KB blocks, at 8MB blocks, the network will
> > just fall apart as a significant portion of the hashing power SPV
> > mines throughout. All a single malicious miner has to do is mine an
> > invalid block on purpose, let these pools SPV mine on top of them
> > while it mines a valid block free of their competition. Yes, these
> > pools deserve to lose money in that event, but the impact of reorgs
> > and many block orphans for anyone not running a full node could be
> > disastrous, especially more so in the XT world where Mike wants
> > everyone to be running SPV nodes. I simply don't see the XT fork
> > having any chance of surviving if SPV nodes are unreliable.
> > 
> > And if these pools go out of business, it will lead to even more
> > mining centralization which is already too centralized today.
> > 
> > Can anyone representing these pools comment on why this is happening?
> > Are these pools on Matt's relay network?
> > 
> > 
> > _______________________________________________
> > bitcoin-dev mailing list
> > bitcoin-dev@lists•linuxfoundation.org
> > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
> 

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