configurable gas buffer

TODO.md

@@ -308,6 +308,7 @@ These are not yet ordered. There might be duplicates. We might not actually need
 - [x] retry another server if we get a jsonrpc response error about rate limits
 - [x] major refactor to only use backup servers when absolutely necessary
 - [x] remove allowed lag
+- [x] configurable gas buffer. default to the larger of 25k or 25% on polygon to work around erigon bug
 - [-] proxy mode for benchmarking all backends
 - [-] proxy mode for sending to multiple backends
 - [-] let users choose a % of reverts to log (or maybe x/second). someone like curve logging all reverts will be a BIG database very quickly

web3_proxy/src/app/mod.rs

@@ -25,6 +25,7 @@ use entities::sea_orm_active_enums::LogLevel;
 use entities::user;
 use ethers::core::utils::keccak256;
 use ethers::prelude::{Address, Block, Bytes, Transaction, TxHash, H256, U64};
+use ethers::types::U256;
 use ethers::utils::rlp::{Decodable, Rlp};
 use futures::future::join_all;
 use futures::stream::{FuturesUnordered, StreamExt};
@@ -1119,19 +1120,14 @@ impl Web3ProxyApp {
             // TODO: eth_sendPrivateTransaction (https://docs.flashbots.net/flashbots-auction/searchers/advanced/rpc-endpoint#eth_sendprivatetransaction)
             "eth_coinbase" => {
                 // no need for serving coinbase
-                // we could return a per-user payment address here, but then we might leak that to dapps
                 // no stats on this. its cheap
                 json!(Address::zero())
             }
-            /*
-            // erigon was giving bad estimates. but now it doesn't need it
-            // TODO: got reports of some gas estimate issue on polygon with their erc20s. maybe we do want it
             "eth_estimateGas" => {
-                // TODO: eth_estimateGas using anvil?
-                // TODO: modify the block requested?
                 let mut response = self
                     .balanced_rpcs
-                    .try_send_best_upstream_server(
+                    .try_proxy_connection(
+                        proxy_mode,
                         authorization,
                         request,
                         Some(&request_metadata),
@@ -1139,11 +1135,9 @@ impl Web3ProxyApp {
                     )
                     .await?;
 
-                let parsed_gas_estimate = if let Some(gas_estimate) = response.result.take() {
-                    let parsed_gas_estimate: U256 = serde_json::from_str(gas_estimate.get())
-                        .context("gas estimate result is not an U256")?;
-
-                    parsed_gas_estimate
+                let mut gas_estimate: U256 = if let Some(gas_estimate) = response.result.take() {
+                    serde_json::from_str(gas_estimate.get())
+                        .context("gas estimate result is not an U256")?
                 } else {
                     // i think this is always an error response
                     let rpcs = request_metadata.backend_requests.lock().clone();
@@ -1151,13 +1145,21 @@ impl Web3ProxyApp {
                     return Ok((response, rpcs));
                 };
 
-                // increase by 1.01%
-                let parsed_gas_estimate =
-                    parsed_gas_estimate * U256::from(101_010) / U256::from(100_000);
+                let gas_increase =
+                    if let Some(gas_increase_percent) = self.config.gas_increase_percent {
+                        let gas_increase = gas_estimate * gas_increase_percent / U256::from(100);
 
-                json!(parsed_gas_estimate)
+                        let min_gas_increase = self.config.gas_increase_min.unwrap_or_default();
+
+                        gas_increase.max(min_gas_increase)
+                    } else {
+                        self.config.gas_increase_min.unwrap_or_default()
+                    };
+
+                gas_estimate += gas_increase;
+
+                json!(gas_estimate)
             }
-            */
             // TODO: eth_gasPrice that does awesome magic to predict the future
             "eth_hashrate" => {
                 // no stats on this. its cheap

web3_proxy/src/bin/web3_proxy_cli/main.rs

@@ -16,6 +16,7 @@ mod user_import;
 
 use anyhow::Context;
 use argh::FromArgs;
+use ethers::types::U256;
 use log::{info, warn};
 use std::{
     fs,
@@ -127,7 +128,10 @@ fn main() -> anyhow::Result<()> {
             .context(format!("checking for config at {}", top_config_path))?;
 
         let top_config: String = fs::read_to_string(top_config_path)?;
-        let top_config: TopConfig = toml::from_str(&top_config)?;
+        let mut top_config: TopConfig = toml::from_str(&top_config)?;
+
+        // TODO: this doesn't seem to do anything
+        proctitle::set_title(format!("web3_proxy-{}", top_config.app.chain_id));
 
         if cli_config.db_url.is_none() {
             cli_config.db_url = top_config.app.db_url.clone();
@@ -137,8 +141,15 @@ fn main() -> anyhow::Result<()> {
             cli_config.sentry_url = Some(sentry_url);
         }
 
-        // TODO: this doesn't seem to do anything
-        proctitle::set_title(format!("web3_proxy-{}", top_config.app.chain_id));
+        if top_config.app.chain_id == 137 {
+            if top_config.app.gas_increase_min.is_none() {
+                top_config.app.gas_increase_min = Some(U256::from(25_000));
+            }
+
+            if top_config.app.gas_increase_percent.is_none() {
+                top_config.app.gas_increase_percent = Some(U256::from(25));
+            }
+        }
 
         Some(top_config)
     } else {

web3_proxy/src/config.rs

@@ -4,6 +4,7 @@ use crate::rpcs::request::OpenRequestHandleMetrics;
 use crate::{app::AnyhowJoinHandle, rpcs::blockchain::ArcBlock};
 use argh::FromArgs;
 use ethers::prelude::TxHash;
+use ethers::types::U256;
 use hashbrown::HashMap;
 use log::warn;
 use migration::sea_orm::DatabaseConnection;
@@ -90,6 +91,12 @@ pub struct AppConfig {
     /// None = allow all requests
     pub default_user_max_requests_per_period: Option<u64>,
 
+    /// minimum amount to increase eth_estimateGas results
+    pub gas_increase_min: Option<U256>,
+
+    /// percentage to increase eth_estimateGas results. 100 == 100%
+    pub gas_increase_percent: Option<U256>,
+
     /// Restrict user registration.
     /// None = no code needed
     pub invite_code: Option<String>,