Subject: Re: [Bitcoin-development] Hard fork via miner vote

From: Pieter Wuille <[email-masked]>
Date: Sat, 20 Jun 2015 20:11:53 +0200

On Sat, Jun 20, 2015 at 7:26 PM, David Vorick <[email-masked]>
wrote:

> I see it as unreasonable to expect all nodes to upgrade during a hardfork.
> If you are intentionally waiting for that to happen, it's possible for an
> extreme minority of nodes to hold the rest of the network hostage by simply
> refusing to upgrade. However you want nodes to be able to protest until it
> is clear that they have lost the battle without being at risk of getting
> hardforked out of the network unexpectedly.
>

You can't observe the majority of nodes, only miners, and weighed by
hashrate. If you need a mechanism for protest, that should happen before
the hard fork change code is rolled out. I am assuming a completely
uncontroversial change, in order to not confuse this discussion with the
debate about what hard forks should be done.

So I am not talking about protest, just about deploying a change. And yes,
it is unreasonable to expect that every single node will upgrade. But there
is a difference between ignoring old unmaintained nodes that do not
influence anyone's behaviour, and ignoring the nodes that power miners
producing actual blocks. In addition, having no blocks on the old chain is
safer than producing a small number, as you want full nodes that have not
noticed the fork to fail rather than see a slow but otherwise functional
chain.

-- 
Pieter