Subject: Re: [bitcoin-dev] Fwd: Block size following technological growth

From: Pieter Wuille <[email-masked]>
Date: Thu, 6 Aug 2015 17:26:11 +0200

On Thu, Aug 6, 2015 at 5:06 PM, Gavin Andresen <[email-masked]>
wrote:

> On Thu, Aug 6, 2015 at 10:53 AM, Pieter Wuille <[email-masked]>
> wrote:
>
>> So if we would have 8 MB blocks, and there is a sudden influx of users
>> (or settlement systems, who serve much more users) who want to pay high
>> fees (let's say 20 transactions per second) making the block chain
>> inaccessible for low fee transactions, and unreliable for medium fee
>> transactions (for any value of low, medium, and high), would you be ok with
>> that?
>
>
> Yes, that's fine. If the network cannot handle the transaction volume that
> people want to pay for, then the marginal transactions are priced out. That
> is true today (otherwise ChangeTip would be operating on-blockchain), and
> will be true forever.
>

The network can "handle" any size. I believe that if a majority of miners
forms SPV mining agreements, then they are no longer affected by the block
size, and benefit from making their blocks slow to validate for others (as
long as the fee is negligable compared to the subsidy). I'll try to find
the time to implement that in my simulator. Some hardware for full nodes
will always be able to validate and index the chain, so nobody needs to run
a pesky full node anymore and they can just use a web API to validate
payments.

Being able the "handle" a particular rate is not a boolean question. It's a
question of how much security, centralization, and risk for systemic error
we're willing to tolerate. These are not things you can just observe, so
let's keep talking about the risks, and find a solution that we agree on.

>
>> If so, why is 8 MB good but 1 MB not? To me, they're a small constant
>> factor that does not fundamentally improve the scale of the system.
>
>
> "better is better" -- I applaud efforts to fundamentally improve the
> scalability of the system, but I am an old, cranky, pragmatic engineer who
> has seen that successful companies tackle problems that arise and are
> willing to deploy not-so-perfect solutions if they help whatever short-term
> problem they're facing.
>

I don't believe there is a short-term problem. If there is one now, there
will be one too at 8 MB blocks (or whatever actual size blocks are
produced).

>
>
>> I dislike the outlook of "being forever locked at the same scale" while
>> technology evolves, so my proposal tries to address that part. It
>> intentionally does not try to improve a small factor, because I don't think
>> it is valuable.
>
>
> I think consensus is against you on that point.
>

Maybe. But I believe that it is essential to not take unnecessary risks,
and find a non-controversial solution.

-- 
Pieter