From rusty at rustcorp.com.au Fri Apr 22 02:20:56 2022 From: rusty at rustcorp.com.au (Rusty Russell) Date: Fri, 22 Apr 2022 11:50:56 +0930 Subject: [Lightning-dev] Gossip Propagation, Anti-spam, and Set Reconciliation In-Reply-To: References: Message-ID: <87ee1pj1tj.fsf@rustcorp.com.au> Matt Corallo writes: > Sure, if you?re rejecting a large % of channel updates in total > you?re gonna end up hitting degenerate cases, but we can consider > tuning the sync frequency if that becomes an issue. Let's be clear: it's a problem. Allowing only 1 a day, ended up with 18% of channels hitting the spam limit. We cannot fit that many channel differences inside a set! Perhaps Alex should post his more detailed results, but it's pretty clear that we can't stay in sync with this many differences :( > gossip queries is broken in at least five ways. Naah, it's perfect if you simply want to ask "give me updates since XXX" to get you close enough on reconnect to start using set reconciliation. This might allow us to remove some of the other features? But we might end up with a gossip2 if we want to enable taproot, and use blockheight as timestamps, in which case we could probably just support that one operation (and maybe a direct query op). > Like eclair, we don?t bother to rate limit and don?t see any issues with it, though we will skip relaying outbound updates if we?re saturating outbound connections. Yeah, we did as a trial, and in some cases it's become limiting. In particular, people restarting their LND nodes once a day resulting in 2 updates per day (which, in 0.11.0, we now allow). Cheers, Rusty.