Topic: Block Size soft-limit maxing out this AM 6/3/13 (Read 6167 times)

I mean like when you send an IP (might be TCP) packet that has the wrong length or is malformed in someway, some machines not running IPtables will freak out, what if you flood Bitcoin clients with packets full of random junk but legitimate headers, what will happen?



now my client says 12 confims, Blockchain says 9 and mt gox still hasnt credited my btc so who knows. I sent 1.98Btc with a 0.01 fee.

this blockchain limit needs sorting like within weeks not months, it takes the piss how slow transactions are, if this issue cannot be resolved there is no hope for bitcoin to be able to be a real world payment system for reasonable amounts.

Centralized pool operators. Unfortunately that's not new. They've been attacked by these botnet operators for a while. The botnets attack pools in which they're not mining in order to increase the revenues of the pools they're mining in (and thus, their revenues). Some pool operators are already using high-bandwidth ISPs specialized in DDoS protection.

Let's hope ASICs makes mining no longer interesting for botnet operators, and perhaps then they'll leave pools alone.

I think at least some of the Bitcoin nodes are being DDoS'd at any one time. A major attack just yesterday...

https://bitcointalksearch.org/topic/m.1674673

DDoS is an arm wrestling. The one with more bandwidth wins. If the botnet operator is aiming at a single bitcoiner, then this bitcoiner is likely in trouble. But the entire network? His botnet would need more bandwidth than the bandwidth of the entire network combined. Quite unlikely.

Or do you mean DoS through the Bitcoin protocol itself, like trying to flood fake transactions and such? Bitcoin peers have a series of protections against that. The attacker would have to spend a fortune in transaction fees.

ok thanks,

out of interest..
What would  happen if I had a small botnet and DDOS'd spam traffic on the ports Bitcoin uses, does it (bitcoin-qt) have filtering mechanisms or could it cause this kinda slow network propagation?

I wouldn't worry. The last block was 20 mins ago and can be an hour fairly often (due to the laws of probability)
Mt Gox has been slow for the last hour because BTC is making a sustained foray into the 80s, and new all time highs...

I'm seeing slow adjustments in confirmations,

What i mean by that is blockchain.info is showing 9 confirms whilst my Satoshi client and Mt gox only see 8 it's been like this for over 20mins now, why is that? 

Ouch!
Any idea who did this mistake? I mean, it can only be a mistake, right?

Testing in prod is never good... it's particularly worse when you're testing with the equivalent of thousands of dollars....

Well if you follow the transaction back a level, the 106BTC input, tx 1a3137bd3962de42a6b01974066e2940e9cd2cd2a393bb87c0e9c7439a702b31, came from Bitcoin-24.com

I don't know exactly what software Bitcoin-24.com uses, but the transactions in that address are all uncompressed pubkeys, and the inputs to the high-fee transaction are also all uncompressed pubkeys. The reference client has used compressed pubkeys by default since 0.6, so it's probably non-ref code that made the mistake. Equally given that the inputs are all recent transactions, I would suspect that we're not seeing someones mistake with a cold storage wallet or something. In addition the fact that one of the outputs is 0.002BTC implies it's some business with custom software.

I found a bunch of transactions before with weirdly high fees and high volume from from address 1JmQN8NvX3XXWWrJW3rEEcKQMQd5DUgkH3; it's still wasting fees. It's also connected to Bitcoin-24's address by one hop, although, that doesn't necessarily mean anything - it's also connected to Mt. Gox by one hop. That said the transactions around 1JmQN8N are also uncompressed keys, so maybe we're seeing common software for all of them? On the other hand, all the fees are even "human" numbers, so maybe it's just someone showing off their wealth.

Long story short: make your custom transaction generating code as robust as possible. Test, log, and audit everything.

Monthly fees may apply, identify verification may apply, bank account required, limited to a few countries. You can't compare Bitcoin transfers with SEPAs.

Thanks retep for this finding. I really did not consider that one transaction could be responsible. Someone "accidentally" paid $4000 to execute a payment. Ouch! What a coincidence that the world's most expensive payment transfer happened just when bitcoin traffic was so busy...

My concern still stands, that using higher fees as a lever against SatoshiDice-like spam is counterproductive. Just as an overdose of chemotherapy hurts the patient much more than the cancer itself.
There has to be a more intelligent way to rein in abuse of Bitcoin as a messaging system.

For pools with older bitcoind software, changing the soft limit is simply a matter of changing a constant and recompiling.

For pools with recent bitcoind software, changing the soft limit is simply a matter of changing configuration settings:

The soft limit is still just being touched, it hasn't been reached fully. There have been situations where due to Bitcoin market conditions a lot of people are suddenly sending bitcoins, and we have many full blocks in the row. The examples that have been used lately are those situations. That is an exception, most of the time there are a lot of blocks that are not full.

The mining pools haven't done anything about this because there has been no reason to, yet. Now we're quite close to needing to do that so they will probably start doing that. It's in the best interest of a single mining pool to do that, and it's also in the best interest of everyone since not doing that would simply bring bad press to Bitcoin, perhaps quite significant bad press, and userbase shrinkage.

The current recommended fee of 0.0005 is _not_ a low fee, at current price it's 0,015€ per transaction. It would only need to be maybe 3 times that much for people to start avoiding sending 1€ transactions with Bitcoin, if there is any competition. I know that for some uses Bitcoin crushes everything even with that kind of fee, but the whole payment market is changing rapidly and we can't compare the system to a darn wire transfer, which is a ridiculously inefficient system.

Just drop the soft limit and let miners go all the way to the hard one.

Can't pool operators do that on their own? In the worst case, shouldn't that be a simple patch? What are they waiting for?


Oh, it's as simple as changing some configs? So pool operators are voluntarily limiting their blocks with no particular reason?

And some people seem to fear they would go the other way around....

I think I agree. Bitcoin has been getting a lot of positive press from more main stream tech sites lately, but I'm not really looking forward to the day they pick up the max block size issue.
My guess it would attract a lot of negative press, maybe even outright  ridicule (along the lines of "Bitcoin - the touted new world currency - allows you 1 transaction per year!" or something like that.)...
Not to mention how the Slashdot commentariat will have a field day.

That "moonshot" is because someone created a single transaction with 94BTC in fees: 13dffdaef097881acfe9bdb5e6338192242d80161ffec264ee61cf23bc9a1164

Fees are rising, but they haven't spiked like you think they have.

How's your graph look if you filter out SD flooding?

And yes, the 250Kb artificial constraint seemingly has had an immediate effect upon fees!

So, despite the block reward being >$1000, and not due for halving until 3.75 years time, fees are forced to do a moonshot.

Is there now to be an arm-wrestle between the bitcoin-happy public and dice gamblers as to who can tolerate the highest fees? It has been noted how thick-skinned gamblers are to fees. Will we see the whole network exist solely to support dice gamblers? Is that the future for Bitcoin?


http://blockchain.info/charts/transaction-fees-usd

To be precise, the 250KB soft-limit is entirely artificial. In my opinion the 1MB limit is artificial as well, but I do understand some of the reasons to have some constraints on it. I'm however radically against keeping it at 1MB forever.


It's very convenient of you to choose the most inefficient money transfer mechanism available as a comparison. Let's compare this to the European International SEPA bank transfer system. Transfers take usually 1 day to any country these days, and the cost for individuals is 0,0 EUR per transfer. Monthly fees may apply.

The cost for companies in Finland is approximately 0,15€ per transfer, with some banks it's also 0. Our company has 3 bank accounts, one of them only has a monthly fixed fee regardless of the amount of SEPA transfers, the other two have 0,15€ per transfer. And as a reminder again, for non-companies the fees are usually 0. The fees are the same with any amount.

Even if we take the 0,15€ as a baseline, the fees can rise a bit though. In any case, for Europeans the need for SEPA transfers radically exceeds the need for wire transfers. I just think that even 0,15€ is way too much, for me the baseline is how much does a 1€ transaction cost. I'd say an acceptable fee is 2% for that size, which is 0,02€.

At current market price 0.0005 is 0,015€ which is very close to what I'd consider the maximum acceptable fee. Any higher than where we are now, and Bitcoin's usability for small transactions is destroyed. This fee could perhaps be as high as 5% for a 1€ transactions but around that mark is the max, if one wants to give Bitcoin a shot at handling small tx. I'm not even talking about micro-tx, I personally think aiming at handling below 1€ tx should be abandoned.

The one and only problem is the block size which is simply way too low to support scaling of any kind. This is not a question of all or nothing, Bitcoin will certainly not be used for all micro transactions in the world, but if it can't be used for $1 transactions and cheaply, it's absolutely doomed.

This year there needs to be concrete progress in the plan to raise the block size, otherwise I'm abandoning ship for certain. My view is that this particular issue is THE issue as far as Bitcoin is concerned right now. My only real concern, to be honest.

I do not think you know the meaning of that word. There are numerous reasons the block size is constrained.


The default fee is about US$.02. International wires cost about $50 and take days to process. Yes, $.02 isn't enough for a international currency transfer averaging 10 minutes. Increase the default fee from BTC .0005 to BTC .01 and the blocks will have plenty of room for everyone's transactions.