Subject: Re: [bitcoin-dev] Scaling Bitcoin conference micro-report

From: Matt Corallo <[email-masked]>
Date: Fri, 18 Sep 2015 20:06:23 +0000

I did not intend to imply that there was agreement on a desire to
schedule a second hardfork. My wording may have been a bit too loose.
Instead, I believe there was much agreement that doing a short-term
hardfork now, with many agreeing that a second would hopefully be
entirely unnecessary/impossible, while others thought that a second
would be necessary and would have to happen. While this may set up a
similar controversy again in several years, I think everyone agreed that
we cannot predict the future and I, personally, think none of us should
be committing to a viewpoint for what should be done at that time.

Personally, I think it is also critical that there be no messaging that
people should rely on or assume there will be a future increase after a
short-term bump (which I also do not believe people should be relying on
now).

Matt

On 09/18/15 05:55, Mark Friedenbach wrote:
> Correction of a correction, in-line:
> 
> On Wed, Sep 16, 2015 at 5:51 PM, Matt Corallo via bitcoin-dev
> <[email-masked]
> <mailto:[email-masked]>> wrote:
> 
>     > - Many interested or at least willing to accept a "short term bump", a
>     > hard fork to modify block size limit regime to be cost-based via
>     > "net-utxo" rather than a simple static hard limit.  2-4-8 and 17%/year
>     > were debated and seemed "in range" with what might work as a short term
>     > bump - net after applying the new cost metric.
> 
>     I would be careful to point out that hard numbers were deliberately NOT
>     discussed. Though some general things were thrown out, they were not
>     extensively discussed nor agreed to. I personally think 2-4 is "in
>     range", though 8 maybe not so much. Of course it depends on exactly how
>     the non-blocksize limit accounting/adjusting is done.
> 
>     Still, the "greatest common denominator" agreement did not seem to be
>     agreeing to an increase which continues over time, but which instead
>     limits itself to a set, smooth increase for X time and then requires a
>     second hardfork if there is agreement on a need for more blocksize at
>     that point.
> 
> 
> Perhaps it is accurate to say that there wasn't consensus at all except
> that (1) we think we can work together on resolving this impasse (yay!),
> and (2) it is conceivable that changing from block size to some other
> metric might provide the basis for a compromise on near-term numbers.
> 
> As an example, I do not think the net-UTXO metric provides any benefit
> with respect to scalability, and in some ways makes the situation worse
> (even though it helpfully solves an unrelated problem of spammy dust
> outputs). But there are other possible metrics and I maintain hope that
> data will show the benefit of another metric or other metrics combined
> with net-UTXO in a way that will allow us to reach consensus.
> 
> As a further example, I also am quite concerned about 2-4-8MB with
> either block size or net-UTXO as the base metric. As you say, it depends
> on how the non-blocksize limit accounting/adjusting is done... But if a
> metric were chosen that addressed my concerns (worst case propagation
> and validation time), then I could be in favor of an initial bump that
> allowed a larger number of typical transactions in a block.
> 
> But where I really need to disagree is on the requirement for a 2nd hard
> fork. I will go on record as being definitively against this. While
> being conservative with respect to exponentials, I would very much like
> to make sure that there is a long-term growth curve as part of any
> proposal. I am willing to accept a hard-fork if the adopted plan is too
> conservative, but I do not want to be kicking the can down the road to a
> scheduled 2nd hard fork that absolutely must occur. That, I feel, could
> be a more dangerous outcome than an exponential that outlasts
> conservative historical trends.
> 
> I commend Jeff for writing a Chatham-rules summary of the outcome of
> some hallway conversations that occurred. On the whole I think his
> summary does represent the majority view of the opinions expressed by
> core developers at the workshop. I will caution though that on nearly
> every issue there were those expressed disagreement but did not fight
> the issue, and those who said nothing and left unpolled opinions.
> Nevertheless this summary is informative as it feeds forwards into the
> design of proposals that will be made prior to the Hong Kong workshop in
> December, in order that they have a higher likelihood of success.