feat(gas_price_service_v1): include max_da_gas_price to control volatility

bin/fuel-core/src/cli/run.rs

@@ -212,6 +212,11 @@ pub struct Command {
     #[arg(long = "min-da-gas-price", default_value = "10000000", env)]
     pub min_da_gas_price: u64,
 
+    /// Maximum DA gas price
+    // DEV: ensure that the max_da_gas_price default is > then the min_da_gas_price default
+    #[arg(long = "max-da-gas-price", default_value = "10000001", env)]
+    pub max_da_gas_price: u64,
+
     /// P component of DA gas price calculation
     /// **NOTE**: This is the **inverse** gain of a typical P controller.
     /// Increasing this value will reduce gas price fluctuations.
@@ -339,6 +344,7 @@ impl Command {
             min_gas_price,
             gas_price_threshold_percent,
             min_da_gas_price,
+            max_da_gas_price,
             da_p_component,
             da_d_component,
             max_da_gas_price_change_percent,
@@ -660,6 +666,7 @@ impl Command {
             memory_pool_size,
             da_gas_price_factor: NonZeroU64::new(100).expect("100 is not zero"),
             min_da_gas_price,
+            max_da_gas_price,
             max_da_gas_price_change_percent,
             da_p_component,
             da_d_component,

crates/fuel-core/src/service/adapters/gas_price_adapters.rs

@@ -71,6 +71,7 @@ impl From<Config> for GasPriceServiceConfig {
             value.exec_gas_price_threshold_percent,
             value.da_gas_price_factor,
             value.min_da_gas_price,
+            value.max_da_gas_price,
             value.max_da_gas_price_change_percent,
             value.da_p_component,
             value.da_d_component,

crates/fuel-core/src/service/config.rs

@@ -86,6 +86,7 @@ pub struct Config {
     pub memory_pool_size: usize,
     pub da_gas_price_factor: NonZeroU64,
     pub min_da_gas_price: u64,
+    pub max_da_gas_price: u64,
     pub max_da_gas_price_change_percent: u16,
     pub da_p_component: i64,
     pub da_d_component: i64,
@@ -216,6 +217,7 @@ impl Config {
             memory_pool_size: 4,
             da_gas_price_factor: NonZeroU64::new(100).expect("100 is not zero"),
             min_da_gas_price: 0,
+            max_da_gas_price: 1,
             max_da_gas_price_change_percent: 0,
             da_p_component: 0,
             da_d_component: 0,

crates/fuel-gas-price-algorithm/src/v1.rs

@@ -1,6 +1,9 @@
 use crate::utils::cumulative_percentage_change;
 use std::{
-    cmp::max,
+    cmp::{
+        max,
+        min,
+    },
     collections::BTreeMap,
     num::NonZeroU64,
     ops::{
@@ -147,6 +150,8 @@ pub struct AlgorithmUpdaterV1 {
     pub gas_price_factor: NonZeroU64,
     /// The lowest the algorithm allows the da gas price to go
     pub min_da_gas_price: u64,
+    /// The highest the algorithm allows the da gas price to go
+    pub max_da_gas_price: u64,
     /// The maximum percentage that the DA portion of the gas price can change in a single block
     ///   Using `u16` because it can go above 100% and possibly over 255%
     pub max_da_gas_price_change_percent: u16,
@@ -514,9 +519,12 @@ impl AlgorithmUpdaterV1 {
             scaled_da_change,
             maybe_new_scaled_da_gas_price
         );
-        self.new_scaled_da_gas_price = max(
-            self.min_scaled_da_gas_price(),
-            maybe_new_scaled_da_gas_price,
+        self.new_scaled_da_gas_price = min(
+            max(
+                self.min_scaled_da_gas_price(),
+                maybe_new_scaled_da_gas_price,
+            ),
+            self.max_scaled_da_gas_price(),
         );
     }
 
@@ -540,6 +548,12 @@ impl AlgorithmUpdaterV1 {
             .saturating_mul(self.gas_price_factor.into())
     }
 
+    fn max_scaled_da_gas_price(&self) -> u64 {
+        // note: here we make sure that a correct maximum is used; hacky :(
+        max(self.max_da_gas_price, self.min_da_gas_price)
+            .saturating_mul(self.gas_price_factor.into())
+    }
+
     fn p(&self) -> i128 {
         let upcast_p = i128::from(self.da_p_component);
         let checked_p = self.last_profit.checked_div(upcast_p);

crates/fuel-gas-price-algorithm/src/v1/tests.rs

@@ -26,6 +26,7 @@ pub struct BlockBytes {
 pub struct UpdaterBuilder {
     min_exec_gas_price: u64,
     min_da_gas_price: u64,
+    max_da_gas_price: u64,
     starting_exec_gas_price: u64,
     starting_da_gas_price: u64,
     exec_gas_price_change_percent: u16,
@@ -53,6 +54,7 @@ impl UpdaterBuilder {
         Self {
             min_exec_gas_price: 0,
             min_da_gas_price: 0,
+            max_da_gas_price: 1,
             starting_exec_gas_price: 1,
             starting_da_gas_price: 1,
             exec_gas_price_change_percent: 0,
@@ -86,6 +88,11 @@ impl UpdaterBuilder {
         self
     }
 
+    fn with_max_da_gas_price(mut self, max_price: u64) -> Self {
+        self.max_da_gas_price = max_price;
+        self
+    }
+
     fn with_starting_exec_gas_price(mut self, starting_da_gas_price: u64) -> Self {
         self.starting_exec_gas_price = starting_da_gas_price;
         self
@@ -192,6 +199,7 @@ impl UpdaterBuilder {
             last_profit: self.last_profit,
             second_to_last_profit: self.second_to_last_profit,
             min_da_gas_price: self.min_da_gas_price,
+            max_da_gas_price: self.max_da_gas_price,
             gas_price_factor: self
                 .da_gas_price_factor
                 .try_into()

crates/fuel-gas-price-algorithm/src/v1/tests/update_da_record_data_tests.rs

@@ -302,6 +302,7 @@ fn update_da_record_data__da_block_lowers_da_gas_price() {
 fn update_da_record_data__da_block_increases_da_gas_price() {
     // given
     let da_cost_per_byte = 40;
+    let max_da_gas_price = u64::MAX;
     let l2_block_height = 11;
     let original_known_total_cost = 150;
     let mut unrecorded_blocks: BTreeMap<_, _> = [(11, 3000)].into_iter().collect();
@@ -320,6 +321,7 @@ fn update_da_record_data__da_block_increases_da_gas_price() {
         .with_projected_total_cost(projected_total_cost as u128)
         .with_known_total_cost(original_known_total_cost as u128)
         .with_unrecorded_blocks(&unrecorded_blocks)
+        .with_max_da_gas_price(max_da_gas_price)
         .build();
 
     let new_cost_per_byte = 100;
@@ -355,6 +357,126 @@ fn update_da_record_data__da_block_increases_da_gas_price() {
     assert_ne!(old_da_gas_price, new_da_gas_price);
 }
 
+#[test]
+fn update_da_record_data__da_block_increases_da_gas_price_within_the_min_max_range() {
+    // given
+    let min_da_gas_price = 0;
+    let max_da_gas_price = 5;
+    let da_cost_per_byte = 40;
+    let l2_block_height = 11;
+    let original_known_total_cost = 150;
+    let mut unrecorded_blocks: BTreeMap<_, _> = [(11, 3000)].into_iter().collect();
+    let da_p_component = 2;
+    let guessed_cost: u64 = unrecorded_blocks
+        .values()
+        .map(|bytes| bytes * da_cost_per_byte)
+        .sum();
+    let projected_total_cost = original_known_total_cost + guessed_cost;
+
+    let mut updater = UpdaterBuilder::new()
+        .with_da_cost_per_byte(da_cost_per_byte as u128)
+        .with_da_p_component(da_p_component)
+        .with_last_profit(-10, 0)
+        .with_l2_block_height(l2_block_height)
+        .with_projected_total_cost(projected_total_cost as u128)
+        .with_known_total_cost(original_known_total_cost as u128)
+        .with_unrecorded_blocks(&unrecorded_blocks)
+        .with_min_da_gas_price(min_da_gas_price)
+        .with_max_da_gas_price(max_da_gas_price)
+        .build();
+
+    let new_cost_per_byte = 100;
+    let (recorded_heights, recorded_cost) = unrecorded_blocks.iter().fold(
+        (vec![], 0),
+        |(mut range, cost), (height, bytes)| {
+            range.push(height);
+            (range, cost + bytes * new_cost_per_byte)
+        },
+    );
+
+    let min = *recorded_heights.iter().min().unwrap();
+    let max = *recorded_heights.iter().max().unwrap();
+    let recorded_range = *min..=*max;
+    let recorded_bytes = 500;
+
+    let old_da_gas_price = updater.new_scaled_da_gas_price;
+
+    // when
+    updater
+        .update_da_record_data(
+            recorded_range,
+            recorded_bytes,
+            recorded_cost as u128,
+            &mut unrecorded_blocks,
+        )
+        .unwrap();
+
+    // then
+    let new_da_gas_price = updater.new_scaled_da_gas_price;
+    // because the profit is -10 and the da_p_component is 2, the new da gas price should be greater than the previous one.
+    assert_eq!(new_da_gas_price, max_da_gas_price);
+    assert_ne!(old_da_gas_price, new_da_gas_price);
+}
+
+#[test]
+fn update_da_record_data__sets_da_gas_price_to_min_da_gas_price_when_max_lt_min() {
+    // given
+    let min_da_gas_price = 1;
+    let max_da_gas_price = 0;
+    let da_cost_per_byte = 40;
+    let l2_block_height = 11;
+    let original_known_total_cost = 150;
+    let mut unrecorded_blocks: BTreeMap<_, _> = [(11, 3000)].into_iter().collect();
+    let da_p_component = 2;
+    let guessed_cost: u64 = unrecorded_blocks
+        .values()
+        .map(|bytes| bytes * da_cost_per_byte)
+        .sum();
+    let projected_total_cost = original_known_total_cost + guessed_cost;
+
+    let mut updater = UpdaterBuilder::new()
+        .with_da_cost_per_byte(da_cost_per_byte as u128)
+        .with_da_p_component(da_p_component)
+        .with_last_profit(-10, 0)
+        .with_l2_block_height(l2_block_height)
+        .with_projected_total_cost(projected_total_cost as u128)
+        .with_known_total_cost(original_known_total_cost as u128)
+        .with_unrecorded_blocks(&unrecorded_blocks)
+        .with_min_da_gas_price(min_da_gas_price)
+        .with_max_da_gas_price(max_da_gas_price)
+        .build();
+
+    let new_cost_per_byte = 100;
+    let (recorded_heights, recorded_cost) = unrecorded_blocks.iter().fold(
+        (vec![], 0),
+        |(mut range, cost), (height, bytes)| {
+            range.push(height);
+            (range, cost + bytes * new_cost_per_byte)
+        },
+    );
+
+    let min = *recorded_heights.iter().min().unwrap();
+    let max = *recorded_heights.iter().max().unwrap();
+    let recorded_range = *min..=*max;
+    let recorded_bytes = 500;
+
+    // when
+    updater
+        .update_da_record_data(
+            recorded_range,
+            recorded_bytes,
+            recorded_cost as u128,
+            &mut unrecorded_blocks,
+        )
+        .unwrap();
+
+    // then
+    let new_da_gas_price = updater.new_scaled_da_gas_price;
+
+    // because max_da_gas_price = 0 and < min_da_gas_price = 1, the new da gas price should be min_da_gas_price
+    assert_eq!(new_da_gas_price, min_da_gas_price);
+}
+
 #[test]
 fn update_da_record_data__da_block_will_not_change_da_gas_price() {
     // given

crates/fuel-gas-price-algorithm/src/v1/tests/update_l2_block_data_tests.rs

@@ -24,6 +24,7 @@ fn negative_profit_updater_builder() -> UpdaterBuilder {
     let starting_da_gas_price = 100;
     let starting_cost = u128::MAX;
     let latest_gas_per_byte = i32::MAX; // DA is very expensive
+    let max_da_gas_price = u64::MAX;
     let da_p_component = 100;
     let da_d_component = 10;
     let last_profit = i128::MIN;
@@ -39,6 +40,7 @@ fn negative_profit_updater_builder() -> UpdaterBuilder {
         .with_projected_total_cost(starting_cost)
         .with_da_cost_per_byte(latest_gas_per_byte as u128)
         .with_last_profit(last_profit, last_last_profit)
+        .with_max_da_gas_price(max_da_gas_price)
 }
 
 fn positive_profit_updater_builder() -> UpdaterBuilder {
@@ -399,6 +401,7 @@ fn update_l2_block_data__price_does_not_decrease_more_than_max_percent() {
     let last_profit = i128::MAX; // Large, positive profit to decrease da price
     let last_last_profit = 0;
     let max_da_change_percent = 5;
+    let max_da_gas_price = u64::MAX;
     let large_starting_reward = i128::MAX;
     let mut updater = UpdaterBuilder::new()
         .with_starting_exec_gas_price(starting_exec_gas_price)
@@ -411,6 +414,7 @@ fn update_l2_block_data__price_does_not_decrease_more_than_max_percent() {
         .with_da_cost_per_byte(latest_gas_per_byte as u128)
         .with_last_profit(last_profit, last_last_profit)
         .with_da_max_change_percent(max_da_change_percent)
+        .with_max_da_gas_price(max_da_gas_price)
         .build();
     let unrecorded_blocks = &mut empty_unrecorded_blocks();
 
@@ -446,6 +450,7 @@ fn update_l2_block_data__da_price_does_not_increase_more_than_max_percent() {
     let last_profit = i128::MIN; // Large, negative profit to increase da price
     let last_last_profit = 0;
     let max_da_change_percent = 5;
+    let max_da_gas_price = u64::MAX;
     let large_starting_reward = 0;
     let unrecorded_blocks = &mut empty_unrecorded_blocks();
     let mut updater = UpdaterBuilder::new()
@@ -459,6 +464,7 @@ fn update_l2_block_data__da_price_does_not_increase_more_than_max_percent() {
         .with_da_cost_per_byte(latest_gas_per_byte)
         .with_last_profit(last_profit, last_last_profit)
         .with_da_max_change_percent(max_da_change_percent)
+        .with_max_da_gas_price(max_da_gas_price)
         .build();
 
     // when
@@ -487,6 +493,7 @@ fn update_l2_block_data__never_drops_below_minimum_da_gas_price() {
     let starting_exec_gas_price = 0;
     let last_da_gas_price = 100;
     let min_da_gas_price = 100;
+    let max_da_gas_price = min_da_gas_price + 1;
     let starting_cost = 0;
     let latest_gas_per_byte = 0; // DA is free
     let da_p_component = 100;
@@ -507,6 +514,7 @@ fn update_l2_block_data__never_drops_below_minimum_da_gas_price() {
         .with_da_cost_per_byte(latest_gas_per_byte as u128)
         .with_last_profit(last_profit, avg_window)
         .with_min_da_gas_price(min_da_gas_price)
+        .with_max_da_gas_price(max_da_gas_price)
         .build();
 
     // when
@@ -534,6 +542,7 @@ fn update_l2_block_data__even_profit_maintains_price() {
     // given
     let starting_exec_gas_price = 100;
     let starting_da_gas_price = 100;
+    let max_da_gas_price = u64::MAX;
     let starting_cost = 500;
     let latest_cost_per_byte = 10;
     let da_gas_price_denominator = 1;
@@ -548,6 +557,7 @@ fn update_l2_block_data__even_profit_maintains_price() {
         .with_known_total_cost(starting_cost as u128)
         .with_projected_total_cost(starting_cost as u128)
         .with_da_cost_per_byte(latest_cost_per_byte as u128)
+        .with_max_da_gas_price(max_da_gas_price)
         .build();
 
     // when

crates/services/gas_price_service/src/ports.rs

@@ -98,6 +98,7 @@ impl GasPriceServiceConfig {
         l2_block_fullness_threshold_percent: u8,
         gas_price_factor: NonZeroU64,
         min_da_gas_price: u64,
+        max_da_gas_price: u64,
         max_da_gas_price_change_percent: u16,
         da_p_component: i64,
         da_d_component: i64,
@@ -114,6 +115,7 @@ impl GasPriceServiceConfig {
             l2_block_fullness_threshold_percent,
             gas_price_factor,
             min_da_gas_price,
+            max_da_gas_price,
             max_da_gas_price_change_percent,
             da_p_component,
             da_d_component,

crates/services/gas_price_service/src/v1/metadata.rs

@@ -67,6 +67,7 @@ pub struct V1AlgorithmConfig {
     // https://github.com/FuelLabs/fuel-core/issues/2481
     pub gas_price_factor: NonZeroU64,
     pub min_da_gas_price: u64,
+    pub max_da_gas_price: u64,
     pub max_da_gas_price_change_percent: u16,
     pub da_p_component: i64,
     pub da_d_component: i64,
@@ -108,6 +109,7 @@ pub fn updater_from_config(value: &V1AlgorithmConfig) -> AlgorithmUpdaterV1 {
             .l2_block_fullness_threshold_percent
             .into(),
         min_da_gas_price: value.min_da_gas_price,
+        max_da_gas_price: value.max_da_gas_price,
         max_da_gas_price_change_percent: value.max_da_gas_price_change_percent,
         da_p_component: value.da_p_component,
         da_d_component: value.da_d_component,
@@ -166,6 +168,7 @@ pub fn v1_algorithm_from_metadata(
             .l2_block_fullness_threshold_percent
             .into(),
         min_da_gas_price: config.min_da_gas_price,
+        max_da_gas_price: config.max_da_gas_price,
         max_da_gas_price_change_percent: config.max_da_gas_price_change_percent,
         da_p_component: config.da_p_component,
         da_d_component: config.da_d_component,