From niftynei at gmail.com Thu Jun 30 03:06:50 2022 From: niftynei at gmail.com (lisa neigut) Date: Wed, 29 Jun 2022 22:06:50 -0500 Subject: [Lightning-dev] Achieving Zero Downtime Splicing in Practice via Chain Signals In-Reply-To: <CAM1a7P0xDQ7VQpchSYR1ZL=pCKDwCuA_k0E_t6tOKoGpNx79CQ@mail.gmail.com> References: <CAO3Pvs_b+UOvdwJNcAjH2o8-uGLBZ+q=W6R1+QWO=DsgZiDDMg@mail.gmail.com> <87a69wb62i.fsf@rustcorp.com.au> <CAO3Pvs93_XwP4fcLb2KR-4UiSzGFbP7FzSjKFbh4j2jL2x8=wA@mail.gmail.com> <CAM1a7P0xDQ7VQpchSYR1ZL=pCKDwCuA_k0E_t6tOKoGpNx79CQ@mail.gmail.com> Message-ID: <CAM1a7P17khzj9kCcRhC_y4yrsLAHR=dAA_i24XwTQYvi67cP6w@mail.gmail.com> Had another thought: if you've seen a chain close but also have a gossip message that indicates this is a splice, you SHOULD propagate that gossip more urgently/widely than any other gossip you've got. Adding an urgency metric to gossip is fuzzy to enforce... *handwaves*. You *do* get the onchain signal, we just change the behavior of the secondary information system instead of embedding the info into the chain.. "Spamming" gossip with splices expensive -- there's a real-world cost (onchain fees) to closing a channel (the signal to promote/prioritize a gossip msg) which cuts down on the ability to send out these 'urgent' messages with any frequency. ~nifty On Wed, Jun 29, 2022 at 7:43 PM lisa neigut <niftynei at gmail.com> wrote: > Adding a noticeable on-chain signal runs counter to the goal of the move > to taproot / gossip v2, which is to make lightning's onchain footprint > indistinguishable from > any other onchain usage. > > I'm admittedly a bit confused as to why onchain signals are even being > seriously > proposed. Aside from "infallibility", is there another reason for > suggesting > we add an onchain detectable signal for this? Seems heavy handed imo, > given > that the severity of a comms failure is pretty minimal (*potential* for > lost routing fees). > > > So it appears you don't agree that the "wait N blocks before you close > your > channels" isn't a fool proof solution? Why 12 blocks, why not 15? Or 144? > > fwiw I seem to remember seeing that it takes ~an hour for gossip to > propagate > (no link sorry). Given that, 2x an hour or 12 blocks is a reasonable first > estimate. > I trust we'll have time to tune this after we've had some real-world > experience with them. > > Further, we can always add more robust signaling later, if lost routing > fees turns > out to be a huge issue. > > Finally, worth noting that Alex Myer's minisketch project may well > help/improve gossip > reconciliation efficiency to the point where gossip reliability is less > of an issue. > > ~nifty > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.linuxfoundation.org/pipermail/lightning-dev/attachments/20220629/b97093da/attachment.html>