[PATCH] increase block size limit

[jgarzik]

We should be able to at least match Paypal's average transaction rate...

Code:

diff --git a/main.h b/main.h
index c5a0127..c92592a 100644
--- a/main.h
+++ b/main.h
@@ -14,7 +14,10 @@ class CBlockIndex;
 class CWalletTx;
 class CKeyItem;
 
-static const unsigned int MAX_BLOCK_SIZE = 1000000;
+static const unsigned int TX_PER_MINUTE = 1400;
+static const unsigned int TX_AVG_SIZE_GUESS = 256;
+static const unsigned int MAX_BLOCK_SIZE =
+ TX_PER_MINUTE * TX_AVG_SIZE_GUESS * 10 * 2;
 static const unsigned int MAX_BLOCK_SIZE_GEN = MAX_BLOCK_SIZE/2;
 static const int MAX_BLOCK_SIGOPS = MAX_BLOCK_SIZE/50;
 static const int64 COIN = 100000000;

URL: http://yyz.us/bitcoin/patch.bitcoin-block-sz-limit

[theymos]

Applying this patch will make you incompatible with other Bitcoin clients.

[satoshi]

Applying this patch will make you incompatible with other Bitcoin clients.

+1 theymos.  Don't use this patch, it'll make you incompatible with the network, to your own detriment.

We can phase in a change later if we get closer to needing it.

[jgarzik]

We can phase in a change later if we get closer to needing it.

IMO it's a marketing thing.  It's tough to get people to buy into a system, if the network is technically incapable of supporting high transaction rates.

[FreeMoney]

We can phase in a change later if we get closer to needing it.

IMO it's a marketing thing.  It's tough to get people to buy into a system, if the network is technically incapable of supporting high transaction rates.

Satoshi just said it can be changed, so technically the network is capable.

[jgarzik]

We can phase in a change later if we get closer to needing it.

IMO it's a marketing thing.  It's tough to get people to buy into a system, if the network is technically incapable of supporting high transaction rates.

Satoshi just said it can be changed, so technically the network is capable.

It is also an incompatible change, as you see.....

[martin]

No, it's incompatible if just a few people change their behaviour. To roll out a change to the network you need to get most of the clients understanding both the old and the new protocol, and then when you have a majority you turn on the new protocol.

[jgarzik]

No, it's incompatible if just a few people change their behaviour. To roll out a change to the network you need to get most of the clients understanding both the old and the new protocol, and then when you have a majority you turn on the new protocol.

You just described a whole-network upgrade.  I'd call that an incompatible change

The effort to raise the transaction rate limit is the same as the effort to change the fundamental nature of bitcoins:  convince the vast majority to upgrade.

[satoshi]

It can be phased in, like:

if (blocknumber > 115000)
    maxblocksize = largerlimit

It can start being in versions way ahead, so by the time it reaches that block number and goes into effect, the older versions that don't have it are already obsolete.

When we're near the cutoff block number, I can put an alert to old versions to make sure they know they have to upgrade.

[kiba]

No, it's incompatible if just a few people change their behaviour. To roll out a change to the network you need to get most of the clients understanding both the old and the new protocol, and then when you have a majority you turn on the new protocol.

You just described a whole-network upgrade.  I'd call that an incompatible change

The effort to raise the transaction rate limit is the same as the effort to change the fundamental nature of bitcoins:  convince the vast majority to upgrade.

If we upgrade now, we don't have to convince as much people later if the bitcoin economy continues to grow.

[appamatto]

No, it's incompatible if just a few people change their behaviour. To roll out a change to the network you need to get most of the clients understanding both the old and the new protocol, and then when you have a majority you turn on the new protocol.

You just described a whole-network upgrade.  I'd call that an incompatible change

The effort to raise the transaction rate limit is the same as the effort to change the fundamental nature of bitcoins:  convince the vast majority to upgrade.

If we upgrade now, we don't have to convince as much people later if the bitcoin economy continues to grow.

I agree, especially since generators are both the source of blocks and "votes" in the network.  Since a block restriction would allow generators to charge higher transaction fees, they might "vote" against an increase in the max size in the future.

It seems unlikely to be a real problem though.

[caveden]

Only recently I learned about this block size limit.

I understand not putting any limit might allow flooding. On the other hand, the smaller your block, the faster it will propagate to network (I suppose.. or is there "I've got a block!" sort of message sent before the entire content of the block?), so miners do have an interest on not producing large blocks.

I'm very uncomfortable with this block size limit rule. This is a "protocol-rule" (not a "client-rule"), what makes it almost impossible to change once you have enough different softwares running the protocol. Take SMTP as an example... it's unchangeable.

I think we should schedule a large increase in the block size limit right now while the protocol rules are easier to change. Maybe even schedule an infinite series of increases, as we can't really predict how many transactions there will be 50 years from now.

Honestly, I'd like to get rid of such rule. I find it dangerous. But I can't think of an easy way to stop flooding without it, though.

[ArticMine]

It can be phased in, like:

if (blocknumber > 115000)
    maxblocksize = largerlimit

It can start being in versions way ahead, so by the time it reaches that block number and goes into effect, the older versions that don't have it are already obsolete.

When we're near the cutoff block number, I can put an alert to old versions to make sure they know they have to upgrade.

It is time to revive this old thread since this should serve as a wakeup call to the Bitcoin community.

My question is this: What will happen first?
1) Bitcoin transaction volume increases by a factor of 4
2) Current Bitcoin clients become obsolete.

[markm]

Hmm Satoshi wrote that over two years ago and we still aren't actually close to needing it yet.

Still I guess it mostly depends on how many more years it is going to be before someone actually goes out there and signs up Walmart or President's Choice or A&P (are they still around?) or Sainsbury's or something and actually shows us a little of this vast flood of users they keep yelling is going to descend upon us any moment now.

So far it seems possible the volume of ranting about vast numbers of users coming at us is actually inversely proportional to the number of users the ranter actually has signed up lined up ready to bring aboard.

-MarkM-

[ArticMine]

http://blockchain.info/charts/n-transactions With a 10x increase in the number of transactions over the last year it is reasonable to say that we can reach the 1MB limit in well under a year. The point is that in order to roll out a hard fork one has to delay its implementation way into the future in order to avoid chaos in the network. It we reach the limit before anything is done it will be way too late and a massive loss in confidence will result.

[BitcoinINV]

off-topic and I am sorry but I could not help myself. Why did satoshi ever stop posting visiting us?

[ArticMine]

off-topic and I am sorry but I could not help myself. Why did satoshi ever stop posting visiting us?

There are many theories of this. One of them is can Bitcoin continue to function without centralized control? By leaving us he in effect left Bitcoin leaderless and that is by design. This block size issue is likely to be the perfect test since the community has no choice but to implement a hard fork. If Bitcoin survives this it will come out way stronger, there is however also a significant chance that block size issue will turn Bitcoin into a failed experiment.  By the way I would not consider your post off topic at all.  

[markm]

Isn't a huge huge amount of the increase in transactions so far attributed to what seems to be basically an app designed expressly for the purpose of artifically/frivolously spamming the blockchain with frivolous/trivial, even "dust spam", transactions?

If so it seems more to show desperation on the part of some bigger bigger bigger agenda than any real need. Especially the dust, that is pretty much an attack really, even if intended to highlight a problem existing with tiny value transactions so it can maybe be addressed.

-MarkM-

[Technomage]

http://blockchain.info/charts/n-transactions With a 10x increase in the number of transactions over the last year it is reasonable to say that we can reach the 1MB limit in well under a year. The point is that in order to roll out a hard fork one has to delay its implementation way into the future in order to avoid chaos in the network. It we reach the limit before anything is done it will be way too late and a massive loss in confidence will result.

Exactly. We're not having these discussions too early at all, on the contrary. We will probably need 1 year of lead time for such a massive change, and indeed it is possible that we will be pushing the limit within 1 year. So this is no joke.

[BitcoinINV]

Here soon blockchain.info is going to roll soo fast you can not even see the transactions.