New Solution to Block Size Debate

[Hyena]

I was sleeping and then suddenly I woke up with this idea in my mind: remove the block size limit from every 6th block.

This guarantees that all TXs will be confirmed eventually (in an hour) while not impacting miners too much. Problem solved. Everyone can just STFU already and move on with their lives.

What is that? Do I hear someone complaining about the number 6 or saying that removing the size limit is too much? In that case, I wouldn't care if those constants were different. For example, every 18th block could have the size limit of 8 MiB, all the others would remain 1 MiB. Whatever configuration gets the most supporters.

Now get this idea out there, make it viral, comment, subscribe and question everything!

[lemipawa]

How would that be different from having a large block size limit or none at all? It would just guarantee that a transaction will be confirmed after 6 blocks, whereas no limit confirms after 1 block. There is also still the problem of hundereds of spam and microtransactions bloating the blockchain.

[pereira4]

So doing this would mean that transactions go from 10 minutes to 1 hour of confirmation? Then people would complain about confirmation time being way too slow. You can't please everyone... no matter what you propose, you'll get a group of haters.

[DooMAD]

That's certainly the kind of out-of-the-box thinking that can lead to breakthroughs, but it's difficult to tell on first impression if this would actually work or not.  Firstly, is there any chance miners might attempt to game the system by deliberately targeting or avoiding certain blocks if some will be different sizes?  And secondly, if the total size of all the transactions in the space of an hour added together was, for example, 12MB, would there effectively be any difference in the overall size of the blockchain by making some of the transactions wait a few extra blocks?

i.e.  Five blocks at 1MB and then one at 7MB  would be:  1MB + 1MB + 1MB + 1MB + 1MB + 7MB = 12MB
versus all the blocks being similar sizes over the same period:  2MB + 2MB + 2MB + 2MB + 2MB + 2MB = 12MB

Doesn't really seem to be much of a difference in practice.

Plus it still doesn't solve the issue where if the 1MB blocks are full, you have to guess what fee you need to pay to make it in.  Adding unneeded uncertainty to people's transactions isn't something I'm fond of, to put it mildly.  Bitcoin has a reputation for being fast and reliable and I don't feel we should risk jeopardising that in any way.

[achow101]

i.e.  Five blocks at 1MB and then one at 7MB  would be:  1MB + 1MB + 1MB + 1MB + 1MB + 7MB = 12MB
versus all the blocks being similar sizes over the same period:  2MB + 2MB + 2MB + 2MB + 2MB + 2MB = 12MB

Doesn't really seem to be much of a difference in practice.

Actually, that last block that is larger could become a problem. Miners with limited bandwidth in places such as China could have a high orphan rate after that last block because it would take longer for them to receive the block and begin mining on it. It could theoretically give the miner who mined that block an advantage. This is part of the reason why many Chinese miners were opposed to the 20 MB block size limit.

[goosoodude]

Well, this is out of the box thinking for sure, but the transactions closest to the sixth block would be the most likely on to get included to a block asap. I assume that this would create a troubling demand for transactions to be send when it's coming or a lot of transactions would gather waiting for about an hour in the case that the transactions/day number starts growing.

Something like that could certainly destabilize the fee market a lot. There might also be a lot of competition on who would mine the big block depending on if the fees are kept similar the the standard ones therefore increasing the reward since more transactions are included.

Surely sounds fun as an idea, I wonder how much work it would take for someone to create an alt-coin fork of BTC with such a feature.

[Hyena]

Thanks for the constructive feedback. I didn't think of the possibility that miners could start to avoid mining on those big blocks, for example. But then again, let's suppose that 90% of miners switch off their miners when it's time to mine that 6th block. I am absolutely sure that there will be at least one miner that is willing to confirm that block but it could take too much time for them. Perhaps mining the 6th block should be easier by design? Or, better yet, the mining of the 6th block would be done by proof of stake? Either way, there should be some mechanism for clearing the backlog of unconfirmed transactions and this could be it. We could even imagine if every 144th block was allowed to include all the unconfirmed txs to have the tx mempool cleared once a day.

goosoodude asked whether it would be a simple code change. I'm pretty sure it's would be very simple because all you have to do is to divide the current blockchain height by the number 6 and see if the remainder is zero to allow a bigger block to go through.

Anyway, I hope I got the ball rolling and that we get some more interesting ideas now.

[BTCjust]

it should have been 20M if chinese agreed.

[Lauda]

Thanks for the constructive feedback. I didn't think of the possibility that miners could start to avoid mining on those big blocks, for example. But then again, let's suppose that 90% of miners switch off their miners when it's time to mine that 6th block. I am absolutely sure that there will be at least one miner that is willing to confirm that block but it could take too much time for them. Perhaps mining the 6th block should be easier by design? Or, better yet, the mining of the 6th block would be done by proof of stake? Either way, there should be some mechanism for clearing the backlog of unconfirmed transactions and this could be it. We could even imagine if every 144th block was allowed to include all the unconfirmed txs to have the tx mempool cleared once a day.

goosoodude asked whether it would be a simple code change. I'm pretty sure it's would be very simple because all you have to do is to divide the current blockchain height by the number 6 and see if the remainder is zero to allow a bigger block to go through.

Anyway, I hope I got the ball rolling and that we get some more interesting ideas now.

Actually your solution wouldn't even work. We already have miners that occasionally mine a block with 0 transactions in it. What would be stopping them from implementing a counter in the mining software so that they do the same on this 'unlimited block'? Nothing really.
Besides, the solution isn't good because it can't handle enough transactions.

[Argwai96]

it should have been 20M if chinese agreed.

arent most of the chinese miners calling for a 8mb size block ? what if 70% agreeds for the 20mb

[brunoshady]

6 blocks will still be too long of a wait, couldnt they just alternate between the size limit for every block?

[DooMAD]

6 blocks will still be too long of a wait, couldnt they just alternate between the size limit for every block?

We could alternate, but again, it still doesn't make the transactions any smaller overall, so delaying them by a single block or six makes no discernible difference in the end.  The overall outcome is that the size of the blockchain still grows by the amount of transactions that are processed.  There's no solution involving delaying transactions that means we eventually process fewer of them, which means there's no real benefit in delaying them to begin with.

[MicroGuy]

it should have been 20M if chinese agreed.

arent most of the chinese miners calling for a 8mb size block ? what if 70% agreeds for the 20mb

I predict that the ultimate decision regarding blocksize will be made by Coinbase.

[Meuh6879]

i like the gradual increase of block ...

now : 1Mb
2017 : 4Mb
2019 : 8Mb
...etcs...

[jeannemadrigal2]

I like this out of the box thinking.  I am not sure that this is the best solution to the limit, if there is an increase why not just make it every block?  With this solution you are basically averaging up the block size, no?  So in stead why not just make a small increase, like make the limit 1.5 mb, or 2mb instead?  This is a really good discussion though, if we can have discussions like this without trolls and fud, then we will generate some nice ideas.  I have faith in the talent and intelligence of this community.

[Hyena]

Actually your solution wouldn't even work. We already have miners that occasionally mine a block with 0 transactions in it. What would be stopping them from implementing a counter in the mining software so that they do the same on this 'unlimited block'? Nothing really.
Besides, the solution isn't good because it can't handle enough transactions.

Actually you are overly pessimistic about it and not even thinking about the possibility that not all miners are selfish.

So let's say 9 out of 10 miners are selfish and decide not to include any TXs in the 6th fat block that has no size limit. For the sake of simplicity, let's assume that each of those miners has equally 10% of the hashing power.

Because we have 1 good miner, 10% of blocks will be found by them. That means 10% of the potentially fat blocks (6th blocks) are mined by a righteous miner. The righteous miner will include all unconfirmed transactions in the fat block so the backlog of transactions gets regularly cleared. The only penalty is that instead of once per hour the backlog is cleared once per 10 hours.

And that was pretty much the worst case scenario. In reality, we would have more like 70% of the miners righteous and 30% of them selfish. That means the backlog is cleared once in every ~8 blocks.

[Amph]

i like the gradual increase of block ...

now : 1Mb
2017 : 4Mb
2019 : 8Mb
...etcs...

following a better logic, which follow the supply table, should be 4 by 2016 8 by 2020 and so on, this if we assume that the adoption will be inversely proportional to the halving

[coins101]

Blocks sizes could be based on a dynamic model, say a moving average.

This allows for block size re-targeting.

If transactions keep going up, miners can still earn fees on the leading edge cases, but eventually block sizes will go up to accommodate the majority of transactions.

If the network sees a quiet period, blocks can scale back down, again letting miners earn some fees.

How the re-targeting model should work.....err, that's above my pay grade.

[jbrnt]

Blocks sizes could be based on a dynamic model, say a moving average.
This allows for block size re-targeting.

Satoshi himself said the same thing. He said the blocksize limit is best to be determined by a formula. I think it is easier to arrive at a consensus with a fixed limit. If we have a forumla, we will have more arguments and delays. The 8M limit suggested by the Chinese miners is a good start. It will buy us plenty of time to fix this for the long term.

[Klestin]

Blocks sizes could be based on a dynamic model, say a moving average.

This allows for block size re-targeting.

If transactions keep going up, miners can still earn fees on the leading edge cases, but eventually block sizes will go up to accommodate the majority of transactions.

If the network sees a quiet period, blocks can scale back down, again letting miners earn some fees.

How the re-targeting model should work.....err, that's above my pay grade.

Nobody is talking about increasing the block size - only the maximum block size.  The idea that "blocks can scale back down" in a "quiet period" is not new.  Block sizes automatically vary based on the number of outstanding transactions, and the miner's preferences.  If the limit were changed to 20MB today, it would absolutely, positively have ZERO immediate effect on the block sizes.  They'll continue to be only as large as they have to be.  The only difference that raising the limit will have is that when more than 1MB is needed for a particular block (will likely happen at least a few times this year), the transactions won't have to queue.  That's it.

[coins101]

Blocks sizes could be based on a dynamic model, say a moving average.

This allows for block size re-targeting.

If transactions keep going up, miners can still earn fees on the leading edge cases, but eventually block sizes will go up to accommodate the majority of transactions.

If the network sees a quiet period, blocks can scale back down, again letting miners earn some fees.

How the re-targeting model should work.....err, that's above my pay grade.

Nobody is talking about increasing the block size - only the maximum block size.  The idea that "blocks can scale back down" in a "quiet period" is not new.  Block sizes automatically vary based on the number of outstanding transactions, and the miner's preferences.  If the limit were changed to 20MB today, it would absolutely, positively have ZERO immediate effect on the block sizes.  They'll continue to be only as large as they have to be.  The only difference that raising the limit will have is that when more than 1MB is needed for a particular block (will likely happen at least a few times this year), the transactions won't have to queue.  That's it.

Hey, thanks for the clarification.

I didn't need it  

Increasing blocks to 1GB could still see blocks with 400kb transactions.

Some of the miners care about earning fees. Keeping block sizes dynamic could mean that there is always someone prepared to pay a fee to have their transaction processed a bit faster, as the network would be constantly working to stay just ahead of peak transaction demand.

From 1mb blocks in 2016 to 100GB blocks in 2100, it would be a just-in-time model.

[Klestin]

Some of the miners care about earning fees. Keeping block sizes dynamic could mean that there is always someone prepared to pay a fee to have their transaction processed a bit faster, as the network would be constantly working to stay just ahead of peak transaction demand.

If miners want higher fees, they have the ability right now to get them.  They can set whatever fee policies they like and include only those transactions that meet the requirements.  Transactions that don't meet them are slower to process since they have to way for a more lax miner to include them.  It's a free market system between transactors and miners.  Artificially limiting the block size is completely unnecessary for fee control.  However, with the current 25 BTC reward, the transaction fees are entirely inconsequential.  The miners realize this, and so the current rules they endorse are lax when it comes to fees.  Therefore the entire discussion of fees is moot.

Let me guess, you didn't need this clarification either?  And now you want to move on to yet a third reason why the 1MB limit is the way to go?

[SuperClam]

Some of the miners care about earning fees. Keeping block sizes dynamic could mean that there is always someone prepared to pay a fee to have their transaction processed a bit faster, as the network would be constantly working to stay just ahead of peak transaction demand.

If miners want higher fees, they have the ability right now to get them.  They can set whatever fee policies they like and include only those transactions that meet the requirements.  Transactions that don't meet them are slower to process since they have to way for a more lax miner to include them.  It's a free market system between transactors and miners.  Artificially limiting the block size is completely unnecessary for fee control.  However, with the current 25 BTC reward, the transaction fees are entirely inconsequential.  The miners realize this, and so the current rules they endorse are lax when it comes to fees.  Therefore the entire discussion of fees is moot.
Let me guess, you didn't need this clarification either?  And now you want to move on to yet a third reason why the 1MB limit is the way to go?

Larger blocks (with more kB of tx data) propagate across the network more slowly, increasing the risk of the new tip becoming an orphan.
There is a direct cost to the miner of including additional transactions within the block - lost subsidy rewards (hence empty blocks).

Given this, an intelligent miner (many do not bother) should reach a point of equilibrium, given enough data, at which the risk of lost income due to increased orphan risk is out-weighed by the increased income of including an additional kB of tx data.


I may be mistaken, however, it appeared to me that the OP was suggesting that a fee market (resulting in larger tx fees, and hence a higher equilibrium) might be able to be sustained in concert with a clearing mechanism (in this simplistic case, a single block without limit).

The argument would be that the fee market would exist for high priority transactions which need to "clear"/confirm next block, yet the end-of-days argument that the mempool would then infinitely accrue could be satisfied with the periodic unlimited size block.

[Hyena]

I simply do not understand why miners would be against the larger maximum block sizes. The argument that including more unconfirmed transactions in a block gives the miner a disadvantage is a pseudo argument because miners can still choose what number of TXs to include in a block.

Let's say I'm a whiny little bitch miner with very shitty bandwidth. Even though the maximum block size is 8MiB I deliberately only include no more than 1MiB of TXs in a block that I'm mining. How does the bigger block size impact me negatively then?

The blocks that others have found may be bigger than 1MiB so downloading them could cost me some time. However, do I really have to download the full 8MiB block in order to start mining the next one? I am sure it is technically possible to only download the hash and the proof of work of the latest block (block header?) and I can already start mining the next block. So, what's the big problem? Until I don't know which exact TXs from my mempool were included in the latest block I can mine on an empty block (being a selfish little bitch that I am) and still get my profit.

So fuck you miners and fuck you chinise exchanges who want to harm bitcoin by opposing every improvement to the protocol no matter what. I am absolutely sure that those people are against improvements because they have released their own pathetic shitcoin and now they see bitcoin as a rival.

By the way, I have another idea of improving Bitcoin in the context of blocks getting full and backlog building up: TRANSACTION FEE AUCTIONS.

How does it work? The network must allow double spends with a small exception: it must be possible for the user to override their old transaction with a higher TX fee. That way the client can be shown real time mempool ordered by the TX fees. The user will see their TX in that ordered list and the rank of their TX. The list should separate TXs that fit into the maximum block size and the TXs that are probably going to be left out from the next block. The user must have a possibility to override their old transaction by making a new one with a higher TX fee, so that their TX will move up in the list. This situation will then look like an auction.

Technically, it would be rather simple improvement. When a bitcoin node receives a double spend, it checks whether the outputs and the output amounts of that double spend are exactly the same. The node then checks which TX has a higher TX fee and forgets the other TX. In case the previous TX had a smaller TX fee than the new one, the node will propagate the newly received TX as an update to the TX fee auction.

[bitnanigans]

Better to not have any hard limit at all, and allow a configurable soft limit for miners.

[Hyena]

Better to not have any hard limit at all, and allow a configurable soft limit for miners.

That's a good idea. Miners protect the network so let miners decide how big blocks to allow.

edit:
the max size was implemented because of paranoia and not because of any real reason

[Muhammed Zakir]

Better to not have any hard limit at all, and allow a configurable soft limit for miners.

That's a good idea. Miners protect the network so let miners decide how big blocks to allow.

edit:
the max size was implemented because of paranoia and not because of any real reason

Not true. It was added because of excessive spam transactions. Also see http://bitcoin.stackexchange.com/a/37303.

[Klestin]

Better to not have any hard limit at all, and allow a configurable soft limit for miners.

They already have direct control over the size of the blocks they mine, up to the hard limit of 1MB.  Increasing the limit to 20MB does not remove their ability to set whatever size they want, from 0 to 20MB.

[Hyena]

Better to not have any hard limit at all, and allow a configurable soft limit for miners.

That's a good idea. Miners protect the network so let miners decide how big blocks to allow.

edit:
the max size was implemented because of paranoia and not because of any real reason

Not true. It was added because of excessive spam transactions. Also see http://bitcoin.stackexchange.com/a/37303.

False. Miners could have chosen not to include spam tx-s in the blocks. Your argument is invalid. It was paranoia and hardcoding a max size was a kludgy hack that could have been solved on a different level by the means of prevention. Hardcoding a max block size is fighting with the symptoms and that is just a pathetic means to solve a problem.

[Muhammed Zakir]

Better to not have any hard limit at all, and allow a configurable soft limit for miners.

That's a good idea. Miners protect the network so let miners decide how big blocks to allow.

edit:
the max size was implemented because of paranoia and not because of any real reason

Not true. It was added because of excessive spam transactions. Also see http://bitcoin.stackexchange.com/a/37303.

False. Miners could have chosen not to include spam tx-s in the blocks. Your argument is invalid. It was paranoia and hardcoding a max size was a kludgy hack that could have been solved on a different level by the means of prevention. Hardcoding a max block size is fighting with the symptoms and that is just a pathetic means to solve a problem.

It is hard to predict who mines next block and we can't enforce miners to include or exclude certain transactions. OP_RETURN was also used to spam blockchain and your argument of miners choosing is invalid IMHO.

[Hyena]

It is hard to predict who mines next block and we can't enforce miners to include or exclude certain transactions. OP_RETURN was also used to spam blockchain and your argument of miners choosing is invalid IMHO.

Oh and now we have much better situation, right? I'd say that miners choosing the block size is the lesser evil. Miners could also combine their power and make a 51% attack, think of that. Miners have the ultimate power either way. They can mine zero tx blocks if they want to, they can decide what TXs to include and what not even though we have the max block size limit. Right now bitcoin is heading towards slow and painful death due to Satoshi's paranoia and distrust for miners. HOW ON EARTH CAN YOU DISTRUST MINERS IF THEY SECURE THE NETWORK?!

There's also a possibility to vote with your bitcoins what the block size limit should be and that voting can be included in the block chain itself. Take a look at NuShares and how shareholders pass motions in their network. The votes are stored in the block chain and the protocol counts the votes and decides what the maximum block size limit should be. Miners can vote with their coins that they mine. Bitcoin holders can vote with theirs. We have the technical capabilities to solve this problem democratically and yet  I see people only throwing trash at any improvement suggestions. From this I deduce that you are the traitors of the bitcoin network and should be banished from bitcoinland forever.

[Muhammed Zakir]

It is hard to predict who mines next block and we can't enforce miners to include or exclude certain transactions. OP_RETURN was also used to spam blockchain and your argument of miners choosing is invalid IMHO.

Oh and now we have much better situation, right? I'd say that miners choosing the block size is the lesser evil. Miners could also combine their power and make a 51% attack, think of that. Miners have the ultimate power either way. They can mine zero tx blocks if they want to, they can decide what TXs to include and what not even though we have the max block size limit. Right now bitcoin is heading towards slow and painful death due to Satoshi's paranoia and distrust for miners. HOW ON EARTH CAN YOU DISTRUST MINERS IF THEY SECURE THE NETWORK?!

Out of curiosity, have you at least took the time to read old discussions to know why a limit was set? I am not distrusting miners, instead, I am telling it is a security measure. Bitcoin is still vulnerable to DOS. FYI I am not telling we should not raise block size limit. I am only falsifying your statement "limit was set without any reason".

There's also a possibility to vote with your bitcoins what the block size limit should be and that voting can be included in the block chain itself. Take a look at NuShares and how shareholders pass motions in their network. The votes are stored in the block chain and the protocol counts the votes and decides what the maximum block size limit should be. Miners can vote with their coins that they mine. Bitcoin holders can vote with theirs. We have the technical capabilities to solve this problem democratically and yet  I see people only throwing trash at any improvement suggestions. From this I deduce that you are the traitors of the bitcoin network and should be banished from bitcoinland forever.

I don't that would be a secure way. People owning big amounts could easily alter it. CMIIW.

[Hyena]

I am only falsifying your statement "limit was set without any reason".

That was not my statement. Bitcoin has always been and will always be vulnerable to some kinds of theoretical attacks. If miners wanted to, they can do all sorts of nasty things to the network. Satoshi's decision was fighting with the symptoms and was never a good solution for the long term. I agree that when the network was young it was sort of a safety measure similarly to having block chain check points hardcoded into the protocol. These days are over now, it's time to grow up and ditch those safety wheels.

I don't that would be a secure way. People owning big amounts could easily alter it. CMIIW.

Holy shit, people owning big amounts of shares in any company are also in advantage when voting for change. That's how it's supposed to be. You have more coins, that means you're a bigger stakeholder and your vote must count more.

[Muhammed Zakir]

I am only falsifying your statement "limit was set without any reason".

That was not my statement. Bitcoin has always been and will always be vulnerable to some kinds of theoretical attacks. If miners wanted to, they can do all sorts of nasty things to the network. Satoshi's decision was fighting with the symptoms and was never a good solution for the long term. I agree that when the network was young it was sort of a safety measure similarly to having block chain check points hardcoded into the protocol. These days are over now, it's time to grow up and ditch those safety wheels.

DOS attack is a practical one. Like I said, I am not against increasing block size limit but I am against removing block size limit. You didn't answer this:

Out of curiosity, have you at least took the time to read old discussions to know why a limit was set?
 -snip-

I don't that would be a secure way. People owning big amounts could easily alter it. CMIIW.

Holy shit, people owning big amounts of shares in any company are also in advantage when voting for change. That's how it's supposed to be. You have more coins, that means you're a bigger stakeholder and your vote must count more.

Not for Bitcoin. With this, an organization or a person can easily control Bitcoin and do in their way without consensus. This must not be for Bitcoin.

[Hyena]

DOS attack is a practical one. Like I said, I am not against increasing block size limit but I am against removing block size limit.

You are probably right.

You didn't answer this:

Out of curiosity, have you at least took the time to read old discussions to know why a limit was set?
 -snip-

I wonder why, I wonder why

Not for Bitcoin. With this, an organization or a person can easily control Bitcoin and do in their way without consensus. This must not be for Bitcoin.

But at what cost?!! Do you have any idea how much would it cost to buy more than 50% of all bitcoins? I guess not.