Mike Hearn: We'll have to carry on without miners in China

[alani123]

Whilst it would be nice if miners in China can carry on forever regardless
of their internet situation, nobody has any inherent "right" to mine if
they can't do the job - if miners in China can't get the trivial amounts of
bandwidth required through their firewall and end up being outcompeted then
OK, too bad, we'll have to carry on without them.

But I'm not sure why it should be a big deal. They can always run a node on
a server in Taiwan and connect the hardware to it via a VPN or so.

Source: http://sourceforge.net/p/bitcoin/mailman/message/34161751/

My personal comment:

With the recent revelations, bandwidth issues came into discussion. One would expect that Mike Hearn, a bitcoin core developer would respect the fact that a tremendous percentage of the total hash power in bitcoin's mining network comes from China. If any change made some of the Chinese unable to mine the network would be a lot weaker. Some of the largest ASIC manufacturers that supply the whole world would have to relocate their businesses or even close down. Chinese pools run at a hashrate greater than 50% of the total network.

[os2sam]

And what are we supposed to do about it?  I don't think the Bitcoin community carries allot of weight with the Chinese Government.  So if their government shuts down, or throttles, their internet access then we may have no choice but to carry on without China.

[TheRealSteve]

This should probably be in Bitcoin Forum > Bitcoin > Mining > Mining speculation

If any change made some of the Chinese unable to mine the network would be a lot weaker.
[...]
Chinese pools run at a hashrate greater than 50% of the total network.

Let's imagine for a second that, for some reason, out of nowhere, the Chinese pools (let's say for now that's AntPool, F2Pool, BTCChina and BW.com) would be unable to contribute, and that this would make the network weaker.

But would it?  Sure, in absolute network hash rate, it would.  If that makes you think that it would be easier for somebody to attack the network.. sure, a little bit.  Then again, if somebody really wanted to badly enough, they could do so now.

But then look at the rest of how that network hash rate is distributed.  BitFury (not listed at blockchain, going off of whomined.com here for a bit), KnCMiner, 21 Inc, Slush and Ghash.io are the five next big ones.  Together they make up about 20% of the current network.  If 50% of current dropped, then that would merely double to 40%.  And that's all of them together - not a single one of them is even remotely near weighty enough of on their own.
In those terms, the network would be a little more robust, a little more decentralized, and perhaps a little stronger, albeit skewed more toward private pools.  On the other hand, many of the non-Chinese currently mining with their own gear at Chinese pools (e.g. Antpool) because reasons could switch back to Slush/Ghash.io/BTCGuild or perhaps even P2Pool, evening things out even more.

And what are we supposed to do about it?  I don't think the Bitcoin community carries allot of weight with the Chinese Government.  So if their government shuts down, or throttles, their internet access then we may have no choice but to carry on without China.

Note that this is unrelated to any regulatory or whatever issues.

This is regarding the block size.  Specifically, one of the F2Pool people chimed in saying that while they support larger block sizes, they currently can't handle them.  That is to say, they would have a larger yield of orphans.  Which is okay, the same would apply to other pools facing the same limitations.  However, pools like AntPool, which are stuffed with manufacturer-direct hardware at near-cost, can deal with higher orphans for a while, especially if the prospect is that they can push competitors out of the market.

I recommend reading the entire thread, as Mike's reply taken out of context sounds a fair bit more harsh than it is:
http://sourceforge.net/p/bitcoin/mailman/bitcoin-development/thread/554BE0E1.5030001%40bluematt.me/#msg34093766

[alani123]

I'd also encourage others to read the whole discussion. Sorry if I'm making this look like I take his mail out of context. I guess you're referring to my personal comment after quoting Mike word by word. I'll edit OP to highlight that it's my opinionated comment that comes after the quote.

Link to full discussion that the quote comes from:

http://sourceforge.net/p/bitcoin/mailman/bitcoin-development/?viewmonth=201506&limit=50

[os2sam]

And what are we supposed to do about it?  I don't think the Bitcoin community carries allot of weight with the Chinese Government.  So if their government shuts down, or throttles, their internet access then we may have no choice but to carry on without China.

Note that this is unrelated to any regulatory or whatever issues.

This is regarding the block size.  Specifically, one of the F2Pool people chimed in saying that while they support larger block sizes, they currently can't handle them.  That is to say, they would have a larger yield of orphans.  Which is okay, the same would apply to other pools facing the same limitations.  However, pools like AntPool, which are stuffed with manufacturer-direct hardware at near-cost, can deal with higher orphans for a while, especially if the prospect is that they can push competitors out of the market.

I recommend reading the entire thread, as Mike's reply taken out of context sounds a fair bit more harsh than it is:
http://sourceforge.net/p/bitcoin/mailman/bitcoin-development/thread/554BE0E1.5030001%40bluematt.me/#msg34093766

Steve,
Thanks for the clarification.  This subject was dropped in here with no context and I just assumed it was political discussion with their government.

But the block size discussion is always a choice right?  If a pool can't generate large blocks for a technical reason they can still choose to generate smaller ones? right?.

Anyway I'll read the links when I get the chance.
Thanks,
Sam

[TheRealSteve]

But the block size discussion is always a choice right?  If a pool can't generate large blocks for a technical reason they can still choose to generate smaller ones? right?.

They can still generate smaller blocks, sure.  That's a separate issue, though

[jbrnt]

Chinese pools can still mine and they can produce large blocks. It is problematic formthem when two block of the same height are mined within seconds of each other, the chinese pool has more chance of being orphaned. Their slow connection will impact their profitability and not their capacity to mine.

[cflocation]

This gives me mixed feelings for sure. On one hand I have a large pipe I mine off of and have no issues if there is a larger block-size. On the other hand does this not make the network less secure if 50% of our hash rate might drop off.

[TheRealSteve]

This gives me mixed feelings for sure. On one hand I have a large pipe I mine off of and have no issues if there is a larger block-size. On the other hand does this not make the network less secure if 50% of our hash rate might drop off.

Less secure due to an overall network hash rate drop, sure.  On the other hand, the remaining mining pools do not have anywhere near a majority (aside from the Chinese pools, the next 3 biggest pools are private pools to begin with), so they couldn't attack the network (not that they'd want to anyway) on their own as it is.  Besides, with the Chinese pools effectively gone, any non-Chinese miners using these pools would have to use one of the other pools, e.g. Ghash.io, slush, btcguild, etc.

Now, if the difficulty adjusts, and then the Chinese pools suddenly got back in, and decided to collude, and and and.. then there might be an issue.  That's a whole lot of 'might', though, but I do presume you were speaking theoretically anyway

[alh]

I continue to hear this "Boy the network will sure be more secure if the hash rate goes up", or the inverse. So does that mean if the hash rate goes up by 100 PH, because Antpool adds 95PH things will be "more secure"?

I really don't understand why "more hash" == "more secure". How much is enough?

[alani123]

I believe that it would be largely irresponsible to make mining more inefficient or inaccessible to anyone. Sure, the network would still be too large to be attacked but that shouldn't mean that the core devs are entitled to push a change that could potentially drive off certain miners/pools or make mining for them less reliable.

And we're not talking about a country with just a few hobbyist miners, we're talking about China, a country where some of largest ASIC manufacturers are housed. The country that probably runs close to 50% of bitcoin's hashrate. Just because preventing the Chinese from mining wouldn't destroy bitcoin doesn't mean that it should be done.

In my opinion, if changing the block size would affect 50% of the mining network core developers should think twice about it. It hurts to hear a core dev say that we'll have to carry on without half the mining network. Depriving anyone from access to bitcoin mining because of a change you personally support is selfish. And aside of the ethical part, the side effects could be catastrophic. A little conservative thinking wouldn't hurt Mike imo.

[TheRealSteve]

I really don't understand why "more hash" == "more secure". How much is enough?

That honestly depends on how one defines 'security'... i.e. secure against what?  Let's say a pool adds 1 Exahash.  It's 'more secure' against bad actors who would now have to exceed 1 Exahash somehow to subvert the network instead of the ~335Petahash right now.  On the other hand, that one pool could (turn out to) be the bad actor.  If the mining process is supposed to be secure against, say, a reasonable nation state... we're nowhere near that.  Thankfully, there's more to Bitcoin than just mining.  If the miners don't want to play nice with the exchanges, vendors, etc. then I wouldn't necessarily count on the miners winning out.

if changing the block size would affect 50% of the mining network core developers should think twice about it.

On the other hand, if you (collectively) have 50% of the network hash rate, surely a few bucks / yuan can be spent on network infrastructure to ensure that they continue to have appropriate network access?

Something that was touched on in that thread as well:

Pindar Wong: Perhaps it's best not to assume that investing in Internet network infrastructure's a free or open market everywhere.
Ricardo Filipe: Just like easy ASIC access, low price electricity, etc are not a free and open market.
Pindar Wong: point well made and taken.

As did Mike in the original quoted bit.

[alani123]

Do we actually know that they'd be able to run miners with the same reliability as before just by investing into network infrastructure? We have Gavin saying that his own tests indicate that "it's safe" (without giving the Chinese a specific mention) and Mike Hearn saying that we could go without the Chinese.

[TheRealSteve]

The mining hardware itself really doesn't care.  They just hash the header.  The exact content of the header may change, but whether it contains only a coinbase transaction or umpteenthousand transactions doesn't matter so much.. to a miner that all is just the merkle root bitty thing in the header anyway.

Miners on a slightly grander scale - i.e. including that which interfaces the pure mining hardware with the network in order to collect transactions, get the latest block(s), put it all together, and broadcast the results back to the network, on the other hand, is impacted more greatly.  But the bandwidth required really isn't that great.  I believe some simulations were performed (and later a few errors were found with it, not sufficient to declare the whole thing bunk, but enough to revise some numbers).

There's really quite a bit of good technical discussion about.  I'd say hang back and wait for the conclusions, though, as this debate is far from settled

[sidehack]

Does anyone in favor of microtransaction services like what's surrounding the 21e6 embedded miner plans discussion also specifically disfavor increased block sizes? If stuff like that is supposed to be "the future", the protocol needs to adjust in order to not be thoroughly overwhelmed by the millions of fee-free dust transactions which would be produced by all those DVRs and refrigerators.

[notlist3d]

This Chinese pool currently does not support 20MB blocks, but we didn't even reach 1MB so far.

Chinese ISPs would be able to much more bandwidth without the GFW / throttling and if they are keeping it alive they will be facing bigger problems than losing access to Bitcoin mining.

It is normal that China is mining in big quantity.   They are building most of the miners there so a owner saves on shipping in bulk, they could drive a truck to factory on huge installations and save a lot.

Even if china bans pools they will get around it.  They will set up proxy's on amazon ec2 or other VPN's and get around it.  China already banned this forum but people get around it in China.

[imcoddy]

I think the miners in China will try to keep up the pace, unless there is a harsh cutoff by the GFW, which might be almost impossible(this is also a topic we might have to face/discuss in other thread)

And, Bitcoin will not be the real World Wide Ledger if it goes without a certain country anyway. This title is a bit misleading

[alani123]

I think the miners in China will try to keep up the pace, unless there is a harsh cutoff by the GFW, which might be almost impossible(this is also a topic we might have to face/discuss in other thread)

And, Bitcoin will not be the real World Wide Ledger if it goes without a certain country anyway. This title is a bit misleading

How's the title misleading?

[johnyj]

Node != hash power

Chinese mining farms can connect to a mining pools in HongKong/Singapore and still mine big time