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From: Matt Corallo <lf-lists@mattcorallo.com>
In-Reply-To: <20210914045610.GA25475@erisian.com.au>
Date: Wed, 15 Sep 2021 08:24:43 -0700
Message-Id: <90AD5816-4B44-4BBB-A2FC-39CD381D6395@mattcorallo.com>
References: <20210914045610.GA25475@erisian.com.au>
To: Anthony Towns <aj@erisian.com.au>
Cc: Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] Reorgs on SigNet - Looking for feedback on
	approach and parameters
Precedence: list


> On Sep 13, 2021, at 21:56, Anthony Towns <aj@erisian.com.au> wrote:
> I'm not sure that's really the question you want answered?

Of course it is? I=E2=80=99d like to understand the initial thinking and des=
ign analysis that went into this decision. That seems like an important ques=
tion to ask when seeking changes in an existing system :).

> Mostly
> it's just "this is how mainnet works" plus "these are the smallest
> changes to have blocks be chosen by a signature, rather than entirely
> by PoW competition".
>=20
> For integration testing across many services, I think a ten-minute-average=

> between blocks still makes sense -- protocols relying on CSV/CLTV to
> ensure there's a delay they can use to recover funds, if they specify
> that in blocks (as lightning's to_self_delay does), then significant
> surges of blocks will cause uninteresting bugs.=20

Hmm, why would blocks coming quicker lead to a bug? I certainly hope no one h=
as a bug if their block time is faster than per ten minutes. I presume here,=
 you mean something like =E2=80=9Cif the node can=E2=80=99t keep up with the=
 block rate=E2=80=9D, but I certainly hope the benchmark for may isn=E2=80=99=
t 10 minutes, or really even one.

> It would be easy enough to change things to target an average of 2 or
> 5 minutes, I suppose, but then you'd probably need to propogate that
> logic back into your apps that would otherwise think 144 blocks is around
> about a day.

Why? One useful thing for testing is compressing real time. More broadly, th=
e only issues that I=E2=80=99ve heard around block times in testnet3 are the=
 inconsistency and, rarely software failing to keep up at all.

> We could switch back to doing blocks exactly every 10 minutes, rather
> than a poisson-ish distribution in the range of 1min to 60min, but that
> doesn't seem like that huge a win, and makes it hard to test that things
> behave properly when blocks arrive in bursts.

Hmm, I suppose? If you want to test that the upper bound doesn=E2=80=99t nee=
d to be 100 minutes, though, it could be 10.

> Best of luck to you then? Nobody's trying to sell you on a subscription
> plan to using signet.


lol, yes, I=E2=80=99m aware of that, nor did I mean to imply that anything h=
as to be targeted at a specific person=E2=80=99s requirements. Rather, my po=
int here is that I=E2=80=99m really confused as to who  the target user *is*=
, because we should be building products with target users in mind, even if t=
hose targets are often =E2=80=9Cme=E2=80=9D for open source projects.=