Increase default liquidity_penalty_multiplier_msat

[rust-lightning] / lightning / src / routing / scoring.rs

diff --git a/lightning/src/routing/scoring.rs b/lightning/src/routing/scoring.rs
index d9d0bee3ca59c23ddf61898d0d5599962fac9f06..459303f7d87f0c988293a2360798665570607955 100644 (file)
--- a/lightning/src/routing/scoring.rs
+++ b/lightning/src/routing/scoring.rs
@@ -533,7 +533,7 @@ pub struct ProbabilisticScoringParameters {
        /// payments. This knowledge is decayed over time based on [`liquidity_offset_half_life`]. The
        /// penalty is effectively limited to `2 * liquidity_penalty_multiplier_msat`.
        ///
-       /// Default value: 10,000 msat
+       /// Default value: 40,000 msat
        ///
        /// [`liquidity_offset_half_life`]: Self::liquidity_offset_half_life
        pub liquidity_penalty_multiplier_msat: u64,
@@ -603,7 +603,7 @@ impl Default for ProbabilisticScoringParameters {
        fn default() -> Self {
                Self {
                        base_penalty_msat: 500,
-                       liquidity_penalty_multiplier_msat: 10_000,
+                       liquidity_penalty_multiplier_msat: 40_000,
                        liquidity_offset_half_life: Duration::from_secs(3600),
                }
        }
@@ -666,20 +666,21 @@ impl<L: Deref<Target = u64>, T: Time, U: Deref<Target = T>> DirectedChannelLiqui
        /// Returns a penalty for routing the given HTLC `amount_msat` through the channel in this
        /// direction.
        fn penalty_msat(&self, amount_msat: u64, liquidity_penalty_multiplier_msat: u64) -> u64 {
+               let max_penalty_msat = liquidity_penalty_multiplier_msat.saturating_mul(2);
                let max_liquidity_msat = self.max_liquidity_msat();
                let min_liquidity_msat = core::cmp::min(self.min_liquidity_msat(), max_liquidity_msat);
                if amount_msat > max_liquidity_msat {
-                       u64::max_value()
+                       max_penalty_msat
                } else if amount_msat <= min_liquidity_msat {
                        0
                } else {
                        let numerator = (max_liquidity_msat - amount_msat).saturating_add(1);
                        let denominator = (max_liquidity_msat - min_liquidity_msat).saturating_add(1);
-                       approx::negative_log10_times_1024(numerator, denominator)
-                               .saturating_mul(liquidity_penalty_multiplier_msat) / 1024
+                       let penalty_msat = approx::negative_log10_times_1024(numerator, denominator)
+                               .saturating_mul(liquidity_penalty_multiplier_msat) / 1024;
+                       // Upper bound the penalty to ensure some channel is selected.
+                       penalty_msat.min(max_penalty_msat)
                }
-               // Upper bound the penalty to ensure some channel is selected.
-               .min(2 * liquidity_penalty_multiplier_msat)
        }
 
        /// Returns the lower bound of the channel liquidity balance in this direction.
@@ -2050,16 +2051,16 @@ mod tests {
                let target = target_node_id();
 
                let params = ProbabilisticScoringParameters {
-                       base_penalty_msat: 0, ..Default::default()
+                       base_penalty_msat: 0, liquidity_penalty_multiplier_msat: 1_000, ..Default::default()
                };
                let scorer = ProbabilisticScorer::new(params, &network_graph);
-               assert_eq!(scorer.channel_penalty_msat(42, 128, 1_024, &source, &target), 585);
+               assert_eq!(scorer.channel_penalty_msat(42, 128, 1_024, &source, &target), 58);
 
                let params = ProbabilisticScoringParameters {
-                       base_penalty_msat: 500, ..Default::default()
+                       base_penalty_msat: 500, liquidity_penalty_multiplier_msat: 1_000, ..Default::default()
                };
                let scorer = ProbabilisticScorer::new(params, &network_graph);
-               assert_eq!(scorer.channel_penalty_msat(42, 128, 1_024, &source, &target), 1085);
+               assert_eq!(scorer.channel_penalty_msat(42, 128, 1_024, &source, &target), 558);
        }
 
        #[test]
@@ -2074,7 +2075,7 @@ mod tests {
                let scorer = ProbabilisticScorer::new(params, &network_graph);
                assert_eq!(
                        scorer.channel_penalty_msat(42, u64::max_value(), u64::max_value(), &source, &target),
-                       20_000,
+                       80_000,
                );
        }
 }