Topic: Recent floods by MrBurns (17yhRAYKJvVmBh14HMxYRHp2Z4erWgk1ne) (Read 5131 times)

Free transactions must wait for another block.  Spamming only consumes space in the block reserved for free transactions, fee paying transactions have space (at increasing fee levels) up to 1 meg at this time.  The 1 meg limit is a hard limit, but much discussion about replacing the hard limit with a more flexible rule has already occurred on this forum.


I believe that the network can sustain a level of about 470 transactions per minute at this time, due to the hard limit.  We know that this is not enough,but these are changable rules.

If there is a 50 kb limit per block, what does that mean when legitimate (non-spam) transaction volume reaches that amount?  If each transaction averages 270 bytes, that's less than 200 transactions... and if there's guaranteed to exist only a block every few minutes, wouldn't that mean the whole BitCoin network as a whole cannot sustainably commit an average of more than 200 transactions every few minutes?

There are two things that are going to drive fees in the future even if that isn't an issue at the moment:  CPU bandwidth and disk storage costs.

Simply put, running your computer is going to cost you money, as will storing all of the data.  Eventually there will be people dropping out of the mining business because the chance of getting a block is going to be very low.  I think this is happening even now.

One thing that might induce more people to jump back in is to start demanding fees for transactions, and for that matter all transactions.  It is something I'd love to see put into the current client sooner than later, where each person could start demanding fees for transactions.  Satoshi is trying to put forward an idea of some "charity" transaction where at least a few "free" transactions get put in every once in awhile, but presumably there will eventually be a huge backlog on such transactions.

It mainly is a matter of putting this into the interface where people can start selecting a fee they are expecting.  I realize that there are some who have suggested any sort of transaction with even the smallest fee will be accepted, but I am suggesting that eventually those who are accepting the smaller transactions will likely be "driven from the marketplace" when the number of transactions starts to be very large.  At the moment the issue is mainly that the number of transactions per block is quite small and therefore including any transaction at all is useful.

"runaway disk space" seems like an exaggeration to me. The most free "spam" anyone can send currently is 50kB per block. Anyone who want priority over the spam can send a fee. No matter how small the fee it will give those transactions priority over the spam. I figure 0.01 btc would currently pay for about 50MB of disk space. Do you still think we need to worry?

I just created an account to comment on spam and the connection with fee's.  This seems to be a serious theoretical problem with the current implementation, because it will lead to runaway disk space usage.  And I hope someone can counter my ideas with an explanation or help brainstorm a solution.

Supposedly the market will introduce fees which will curtail spam.  The problem is that there is no real market force to increase fees that I can see.  There is no personal incentive for a given node to charge fees because they only stand to miss out on the fee's that fall below their fee threshold.

It's a "tragedy of the commons". Sure it would benefit the community as a whole to charge fee's, but who's gonna be the first one to increase their fee when they only stand lose potential fee income by doing that.

My understanding is that it costs you nothing extra to perform the block hash search with many low- or no- fee transactions included, but you stand to gain a small profit by including even the extremely low fee transactions.

A couple of points:

Not every miner is going to expect a given fee.  This is sort of an auction market where miners are free to choose any fee that they desire.  This is the reason there has been resistance on this thread to impose any hard rules on the network and in particular the miners.  Thinking it through, I think that is on the whole a good idea.  The possibility exists that rules could be enforced on fees in terms of what blocks get accepted into the network, but what is being said here is that the miner is the one that ultimately decides to accept the block.

BTW, I agree with the principle that miners should be completely free to accept or reject transactions, and would go so far as to say that there shouldn't be any restriction in the network on those blocks for this purpose.  I know this contradicts what I've written earlier, but I guess I'm convinced now that this is the best way.  To me, it is an issue of freedom, and one where a market approach fixes potential problems.  For those who posted earlier, I'm sold!

Into this market place, there is going to be some sort of competition to collect transaction in order to "earn" the transaction fees.  There may be some users who want to try and push the fees to higher levels, so they will be rejecting a transaction that includes a 0.1 fee (to use your example).  However, either through altruism (they just want to be nice to newbies and paupers) or perhaps they are being simply greedy (they want to collect every last possible coin, no matter how little) there will end up being somebody somewhere that will eventually process the transaction.

I'm sort of curious if somebody would include a 0.000001 BTC fee in a microtransaction of < 0.01 BTC, how many miners would process that transaction?  This isn't theoretical, as the current "default" network already rejects these sort of transactions, so it would be up to a new miner that would have to accept these sort of transaction.  Apparently there have been a few miners who are processing all transactions right now.

As the intrinsic value of Bitcoins increases (which seems to be a general trend and strong reason to believe it will continue), the desire to accept minor transactions will increase.  That sounds like a strong limiting factor on the maximum fee that on average a typical bitcoin user will have to pay in order to get a transaction into a block.  You may have to wait a bit longer, but it shouldn't be too long of a wait.  You trade off transaction fees for speed of processing, where a higher transaction fee will be more likely to be accepted.  There certainly will be times where the timeliness of getting the transaction processed is critical, so there are valid reasons for a person making the transaction to want to pay a higher fee from time to time too.

For fees to be reasonable you should figure out your costs first and adjust your fee correspondingly. Currently the whole .bitcoin directory tree seems to be about 227mb (on one of my machines). I recently got a 1tb drive for about $50 so the bitcoin database including log files and all costs me about $0.01135. Current BTC are worth about $0.25 so this disk space costs about 0.0028375 BTC

So if you generate even one block and get NO fees, just the 50BTC standard reward you have paid for a LOT of disk space.
Take 0.01 BTC out of that for disk space and the other 49.99 BTC to pay for the electricity and depreciation on your system and whatever other expenses you have and decide if it is worthwhile for you to try for another block.

If not then QUIT!

You DO NOT need to run a node to play with bitcoin. There are services such as mybitcoin.com that will allow you to keep track of your coins for free! (just the cost of your internet connection).

I don't think we need to worry about free transactions for a long time yet. Not even the spam/spew transactions.

One small question about transaction fee after reading what you wrote:
What is going to happen to a transaction send with a 0.1 fee for example if every miner require a 0.2 fee ? Is it going to timeout, or will it wait forever ?

When I wrote that there were no custom miners and only one set of rules. I updated it:

I'll work on it.  for instance:


This statement from the documentation is simply incorrect.  When you sen transactions, you don't know in advance that "they're going to have to pay a transaction fee" or even how much it might be.  It is a guess, and as mentioned here on this thread the rules about this are not "shared among all Bitcoin users".  It may not even be most Bitcoin users that share any given transaction fee philosophy.

Yeah, it is a wiki.  I can change that and rework that sentence and fix other documentation there, but I am saying that the network rules on this issue are as clear as mud and the only documentation about it is the source code of the reference application, and even that isn't really all that clear.  This thread is to me clearing that up considerably, and I thank those who are at least trying to be patient with me on it.

http://www.bitcoin.org/wiki/doku.php?id=transaction_fee

Correct me if I'm wrong here:  When you send out the data for a transaction, you also send out some coins for a "fee" (which could be zero) that may or may not be accepted by a miner.  If it is accepted, the miner processes the transaction, keeps the fee, and the transaction is adopted into the network.  If the fee isn't sufficient, the transaction is rejected and not incorporated into that block.

The default reference implementation doesn't necessarily require fees except for transactions less than 0.01 BTC at the moment, which is perhaps where our lines of communication are getting fouled up.  This represents the "typical" acceptance of new blocks into the network, but individual miners can choose their own policies and perhaps even be as selective or indiscriminate of whatever transactions have been forwarded.

It is an interesting aspect of Bitcoins and needs to be documented elsewhere.  I'll see what I can do on that end.

This wouldn't even require 50% of the network CPU power.  20% would be enough to "slow the network down" with a significant degrading of service and ramp up the difficulty for the rest of the network considerably.  Then again, you would be a fool to pass up on potential transaction fees simply by only accepting transactions that would permit a high fee or an impossible fee.

My understanding of this is really muddled and I'm not not really sure how the fees are decided or what happens when you type in an address, an amount, and try send some bitcoins to somebody.

Well, you can do all sorts of stuff if you have >50% of network CPU power.

How do you "shop" for transaction fees under this system?  I guess I'm getting very confused here over how this works.

For example, if a miner gets a successful hash, what stops them from "charging" a 95% transaction fee?  What keeps those transactions from getting incorporated into the block and recognized by the network?

Is there a way for you to say "I don't want to pay this fee" and "shop" for a miner that charges smaller fees by simply waiting?

It also sets up an interesting DOS attack where potentially a miner with a large bank of computers could charge very high transaction fees, slowing down or even potentially stopping trades.  I guess the way to stop that would be to get a bunch of computers for yourself and hope you can squeeze in a successful hash at least for yourself to get your transactions put into the network without a fee (presuming you can be selective on the fees for your friends and own addresses).

Is this something that could be put into the user interface, where you can "select" what fees you would be willing to pay?

Other miners.

And if it isn't clear, a miner can only say yes/no to a transactions previously attached fee, he can't take any bite he wants.

As it stands now 3.15 has a lot of free transaction space and that space is given first to transactions with the highest [age]*[value]/[size] correct? Would it be reasonable to make some arbitrary portion of the free space require [age]*[value]/[size] > C ?

Maybe set C so that a standard 1BTC transaction can get into the main free area on the next block. And a .1 can get in after waiting about 10 blocks. And make the area which allows [age]*[value]/[size] < C to let in about a dozen transactions or so.

Hope that makes a little sense.

As it stands now, a spammer can flood the network with millions of 0.01 BTC transactions to himself.

Even when this uses up all free TX slots in a block -- thereby DoS'ing honest bitcoin users -- it will continue to use memory and network resources, because the TX's will hang around in RAM on each node, waiting to get added to a block.

Nothing. Actually, as far as I understand, a miner has no obligation whatsoever to include any transaction in the blocks he produces.

Now, if you want to talk about what's the incentive for a miner to add transactions, well, it's mainly the fees. If a miner stipulates a high fee, people wouldn't pay it, and he would lose the opportunity of grabbing the lower fees that would go for the miner which accepts them.
On the other hand, there aren't much incentives to accept "feeless" transactions... today, as the client doesn't give you the option to add a fee to each transaction, custom miners have a strong incentive to accept such feeless transactions because otherwise they would be screwing the whole bitcoin network, what end up being bad for themselves. But as soon as there is a client that allows the user to specify how much to pay on fees, I don't see why accepting feeless transactions.



No, there ought not.
I am strongly against such thing.
What you are suggesting is price fixing. The whole bitcoin idea is to have sound money, government-proof. If that's what we want to create, how come we are going to try to fix prices on the protocol itself? That's contradictory with the sound economic principles behind Bitcoin.



You sound like those people who want to prevent merchants from proposing very different prices, otherwise is too "chaotic".

Producing a block and storing transactions in it is a service somebody is performing for bitcoin users. It's up to s/he to choose how much to charge.
And anyway, think about it, there is a strong incentive for accepting any transaction with any positive transaction fee in it. Otherwise you'll just be letting it to the next guy who is less restrictive than you.


This limit is client-based, not protocol-based. I suppose (actually, I hope!) that if a custom miner accepts transactions of less than 0,01 BTC, the default client won't reject those blocks. It's just that the miner that comes with the default client has this policy of charging 0,01 fee for <0,01 transactions.

So, this is not a problem at all, and can be changed at any moment by those in charge for the client.

We ended up posting about essentially principle, I just ended up exaggerating it a bit more.

As far as where the fees go, they belong to the miner who creates the work unit.  In other words, using the current generation method, you get 50 BTC (or whatever that will be) plus the transaction fees for processing all of the transactions that happen and get incorporated into that work unit.  In theory, over time it will be primarily transaction fees and not new coins which will be the incentive for creating new work units.