Subject: Re: [bitcoin-dev] Draft BIP : fixed-schedule block size increase

From: Peter Todd <[email-masked]>
Date: Tue, 23 Jun 2015 15:16:59 -0400

On Mon, Jun 22, 2015 at 03:23:09PM -0400, Peter Todd wrote:
> On Mon, Jun 22, 2015 at 02:18:19PM -0400, Gavin Andresen wrote:
> > I promised to write a BIP after I'd implemented
> > increase-the-maximum-block-size code, so here it is. It also lives at:
> > https://github.com/gavinandresen/bips/blob/blocksize/bip-8MB.mediawiki
> 
> It's important that we see a wide range of realistic testing of what an
> 8MB limit could look in the near future. An important part of that
> testing is load testing.
> 
> As of writing the BIP above has no mention of what switchover rules will
> be used for testnet; code floating around has August 1st 2015 as that
> date. I propose we use August 1st 2013.
> 
> This switch over date should be set in the _past_ to allow for the
> creation (via reorg) of a realistic full-load blockchain on testnet to
> fully test the real-world behavior of the entire infrastructure
> ecosystem, including questions like the scalability of block explorers,
> SPV wallets, feasibility of initial syncronization, scalability of the
> UTXO set, etc. While this is of course inconvenient - 2 years of 8MB
> blocks is 840GB worth of data - the Bitcoin ecosystem can-not afford to
> make a change like this blindly.
> 
> I'm sure with a $3.5 billion market cap at stake we can scrape together
> the resources to voluntarily run a few hundred full-load full-nodes for
> testing a change with the potential to destroy that market cap.

Also, as a few people have pointed out to me, the BIP proposal has no
information at all about testing, reproducable or not.

As much of the discussion about the acceptability of this BIP will be
heavily influenced by real world test results we should expect
sufficient information available to understand and reproduce those
tests; the Quality Assurance Test Plan done for BIP16 is a model worth
looking at:

https://github.com/bitcoin/bips/blob/master/bip-0016/qa.mediawiki

-- 
'peter'[:-1]@petertodd.org
000000000000000008c0be16e152f86ab3a271a13c3f41c56228d72990abf7bd