On Fri, Oct 28, 2022 at 09:45:09PM -1000, David A. Harding via bitcoin-dev wrote: > I think this might be understating the problem. A 95% chance of having > an outbound peer accept your tx conversely implies 1 in 20 payments will > fail to propagate on their initial broadcast.
Whether that's terrible or not depends on how easy it is to retry (and how likely the retry is to succeed) after a failure -- if a TCP packet fails, it just gets automatically resent, and if that succeeds, there's a little lag, but your connection is still usable. I think it's *conceivable* that a 5% failure rate could be detectable and automatically rectified. Not that I have a good idea how you'd actually do that, in a way that's efficient/private/decentralised... > Some napkin math: there are about 250,000 transactions a day; if > we round that up to 100 million a year and assume we only want one > transaction per year to fail to initially propagate on a network where > 30% of nodes have adopted a more permissive policy, lightweight clients > will need to connect to over 50 randomly selected nodes.[1] A target failure probability of 1-in-1e8 means: * with 8 connections, you need 90% of the network to support your txs * with 12 connections, you need ~79% * with 24 connections (eg everyone running a long-lived node is listening, so long lived nodes make 12 outbound and receive about ~12 inbound; shortlived nodes just do 24 outbound), you need ~54% So with that success target, and no preferential peering, you need a majority of listening nodes to support your tx's features in most reasonable scenarios, I think. > For a more > permissive policy only adopted by 10% of nodes, the lightweight client > needs to connect to almost 150 nodes. I get 175 connections needed for that scenario; or 153 with a target failure rate of 1-in-10-million. Cheers, aj _______________________________________________ bitcoin-dev mailing list bitcoin-dev@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
