more fork detection work

Cargo.lock

@@ -85,9 +85,9 @@ dependencies = [
 
 [[package]]
 name = "anyhow"
-version = "1.0.62"
+version = "1.0.63"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1485d4d2cc45e7b201ee3767015c96faa5904387c9d87c6efdd0fb511f12d305"
+checksum = "a26fa4d7e3f2eebadf743988fc8aec9fa9a9e82611acafd77c1462ed6262440a"
 dependencies = [
  "backtrace",
 ]
@@ -1245,13 +1245,14 @@ dependencies = [
 
 [[package]]
 name = "dashmap"
-version = "5.3.4"
+version = "5.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3495912c9c1ccf2e18976439f4443f3fee0fd61f424ff99fde6a66b15ecb448f"
+checksum = "907076dfda823b0b36d2a1bb5f90c96660a5bbcd7729e10727f07858f22c4edc"
 dependencies = [
  "cfg-if",
  "hashbrown",
  "lock_api",
+ "once_cell",
  "parking_lot_core 0.9.3",
 ]
 
@@ -2671,9 +2672,9 @@ dependencies = [
 
 [[package]]
 name = "lock_api"
-version = "0.4.7"
+version = "0.4.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "327fa5b6a6940e4699ec49a9beae1ea4845c6bab9314e4f84ac68742139d8c53"
+checksum = "9f80bf5aacaf25cbfc8210d1cfb718f2bf3b11c4c54e5afe36c236853a8ec390"
 dependencies = [
  "autocfg 1.1.0",
  "scopeguard",
@@ -2954,9 +2955,9 @@ dependencies = [
 
 [[package]]
 name = "once_cell"
-version = "1.13.0"
+version = "1.13.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "18a6dbe30758c9f83eb00cbea4ac95966305f5a7772f3f42ebfc7fc7eddbd8e1"
+checksum = "074864da206b4973b84eb91683020dbefd6a8c3f0f38e054d93954e891935e4e"
 
 [[package]]
 name = "oorandom"

TODO.md

@@ -90,7 +90,8 @@
   - whenever blocks were slow, we started checking as fast as possible
 - [x] create user script should allow setting requests per minute
 - [x] cache api keys that are not in the database
-- [x] improve consensus block selection. Our goal is to find the highest work chain with a block over a minimum threshold of sum_soft_limit.
+- [ ] improve consensus block selection. Our goal is to find the highest work chain with a block over a minimum threshold of sum_soft_limit.
+  - [x] i saw a fork of like 300 blocks. probably just because a node was restarted and had fallen behind. need some checks to ignore things that are far behind. this improvement should fix this problem
   - [x] A new block arrives at a connection.
   - [x] It checks that it isn't the same that it already has (which is a problem with polling nodes)
   - [x] If its new to this node...
@@ -113,7 +114,12 @@
         - if all_simple_paths returns no paths, warn about a chain split?
     - [x] now that we have a consensus head with enough soft limit (or an empty set), update SyncedConnections
     - [x] send the block through new head_block_sender
-  - [x] rewrite cannonical_block
+  - [x] rewrite cannonical_block to work as long as there are no forks
+  - [ ] rewrite cannonical_block (again) and related functions to handle forks
+    - [ ] todo!("do something with the old hash. we need to update a bunch more block numbers")
+    - [ ] todo!("handle equal") and also less and greater
+    - [x] "chain is forked" message is wrong. it includes nodes just being on different heights of the same chain. need a smarter check
+      - i think there is also a bug because i've seen "server not synced" a couple times
 - [x] bug around eth_getBlockByHash sometimes causes tokio to lock up
   - i keep a mapping of blocks so that i can go from hash -> block. it has some consistent hashing it does to split them up across multiple maps each with their own lock. so a lot of the time reads dont block writes because they are in different internal maps. this was fine.
   - but after changing my fork detection logic to use the same rules as erigon, i discovered that when you get blocks from a websocket subscription in erigon and geth, theres a missing field (https://github.com/ledgerwatch/erigon/issues/5190). so i added a query to get the block that includes the missing field.
@@ -125,12 +131,9 @@
   - but under heavy load, we hit their rate limits. need a "retry_until_success" function that goes to balanced_rpcs. or maybe store in redis the txids that we broadcast privately and use that to route.
   - [ ] write a function for receipts that tries balanced_rpcs and only on error of all balanced tries privates
 - [-] basic request method stats (using the user_id and other fields that are in the tracing frame)
-- [ ] "chain is forked" message is wrong. it includes nodes just being on different heights of the same chain. need a smarter check
-  - i think there is also a bug because i've seen "server not synced" a couple times
-  - [x] i saw a fork of like 300 blocks. probably just because a node was restarted and had fallen behind. need some checks to ignore things that are far behind
-- [ ] todo!("pick the block on the current consensus chain")
 - [ ] web3connection3.block(...) might wait forever. be sure to do it safely
 - [ ] search for all "todo!"
+- [ ] replace all `.context("no servers in sync")` with proper error type
 
 ## V1
 

redis-rate-limit/Cargo.toml

@@ -5,6 +5,6 @@ authors = ["Bryan Stitt <bryan@stitthappens.com>"]
 edition = "2021"
 
 [dependencies]
-anyhow = "1.0.62"
+anyhow = "1.0.63"
 bb8-redis = "0.11.0"
 tracing = "0.1.36"

redis-rate-limit/src/lib.rs

@@ -84,9 +84,7 @@ impl RedisRateLimit {
             .await
             .context("increment rate limit")?;
 
-        let new_count = x
+        let new_count = x.first().context("check rate limit result")?;
-            .first()
-            .ok_or_else(|| anyhow::anyhow!("check rate limit result"))?;
 
         if new_count > &max_per_period {
             let seconds_left_in_period = self.period - (now % self.period);

web3_proxy/Cargo.toml

@@ -16,7 +16,7 @@ entities = { path = "../entities" }
 migration = { path = "../migration" }
 redis-rate-limit = { path = "../redis-rate-limit" }
 
-anyhow = { version = "1.0.62", features = ["backtrace"] }
+anyhow = { version = "1.0.63", features = ["backtrace"] }
 arc-swap = "1.5.1"
 argh = "0.1.8"
 axum = { version = "0.5.15", features = ["headers", "serde_json", "tokio-tungstenite", "ws"] }
@@ -25,7 +25,7 @@ axum-client-ip = "0.2.0"
 axum-macros = "0.2.3"
 # TODO: turn tokio-console on with a feature. console-subscriber = { version = "0.1.7" }
 counter = "0.5.6"
-dashmap = "5.3.4"
+dashmap = "5.4.0"
 derive_more = "0.99.17"
 dotenv = "0.15.0"
 ethers = { version = "0.17.0", features = ["rustls", "ws"] }

web3_proxy/src/app.rs

@@ -597,7 +597,9 @@ impl Web3ProxyApp {
             self.balanced_rpcs.block_hash(min_block_needed).await?
         } else {
             // TODO: maybe this should be on the app and not on balanced_rpcs
-            self.balanced_rpcs.head_block_hash()
+            self.balanced_rpcs
+                .head_block_hash()
+                .context("no servers in sync")?
         };
 
         // TODO: better key? benchmark this
@@ -724,16 +726,15 @@ impl Web3ProxyApp {
                 serde_json::Value::Array(vec![])
             }
             "eth_blockNumber" => {
-                // TODO: emit stats
+                match self.balanced_rpcs.head_block_num() {
-
+                    Some(head_block_num) => {
-                let head_block_number = self.balanced_rpcs.head_block_num();
+                        json!(head_block_num)
-
+                    }
-                // TODO: technically, block 0 is okay. i guess we should be using an option
+                    None => {
-                if head_block_number.as_u64() == 0 {
+                        // TODO: what does geth do if this happens?
-                    return Err(anyhow::anyhow!("no servers synced"));
+                        return Err(anyhow::anyhow!("no servers synced"));
+                    }
                 }
-
-                json!(head_block_number)
             }
             // TODO: eth_callBundle (https://docs.flashbots.net/flashbots-auction/searchers/advanced/rpc-endpoint#eth_callbundle)
             // TODO: eth_cancelPrivateTransaction (https://docs.flashbots.net/flashbots-auction/searchers/advanced/rpc-endpoint#eth_cancelprivatetransaction, but maybe just reject)
@@ -807,7 +808,10 @@ impl Web3ProxyApp {
             method => {
                 // emit stats
 
-                let head_block_number = self.balanced_rpcs.head_block_num();
+                let head_block_number = self
+                    .balanced_rpcs
+                    .head_block_num()
+                    .context("no servers synced")?;
 
                 // we do this check before checking caches because it might modify the request params
                 // TODO: add a stat for archive vs full since they should probably cost different

web3_proxy/src/rpcs/blockchain.rs

@@ -5,6 +5,7 @@ use super::transactions::TxStatus;
 use crate::{
     config::BlockAndRpc, jsonrpc::JsonRpcRequest, rpcs::synced_connections::SyncedConnections,
 };
+use anyhow::Context;
 use dashmap::{
     mapref::{entry::Entry, one::Ref},
     DashMap,
@@ -13,8 +14,9 @@ use derive_more::From;
 use ethers::prelude::{Block, TxHash, H256, U64};
 use hashbrown::{HashMap, HashSet};
 use petgraph::algo::all_simple_paths;
+use serde::Serialize;
 use serde_json::json;
-use std::sync::Arc;
+use std::{cmp::Ordering, fmt::Display, sync::Arc};
 use tokio::sync::{broadcast, watch};
 use tracing::{debug, info, trace, warn};
 
@@ -23,27 +25,27 @@ pub type ArcBlock = Arc<Block<TxHash>>;
 pub type BlockHashesMap = Arc<DashMap<H256, ArcBlock>>;
 
 /// A block's hash and number.
-#[derive(Default, From)]
+#[derive(Clone, Debug, Default, From, Serialize)]
 pub struct BlockId {
     pub(super) hash: H256,
     pub(super) num: U64,
 }
 
+impl Display for BlockId {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{} ({})", self.num, self.hash)
+    }
+}
+
 impl Web3Connections {
     /// add a block to our map and it's hash to our graphmap of the blockchain
     pub fn save_block(&self, block: &ArcBlock) -> anyhow::Result<()> {
-        let block_hash = block
+        let block_hash = block.hash.as_ref().context("no block hash")?;
-            .hash
+        let block_num = block.number.as_ref().context("no block num")?;
-            .as_ref()
-            .ok_or_else(|| anyhow::anyhow!("no block hash"))?;
-        let block_num = block
-            .number
-            .as_ref()
-            .ok_or_else(|| anyhow::anyhow!("no block num"))?;
         let _block_td = block
             .total_difficulty
             .as_ref()
-            .ok_or_else(|| anyhow::anyhow!("no block total difficulty"))?;
+            .context("no block total difficulty")?;
 
         if self.block_hashes.contains_key(block_hash) {
             // this block is already included. no need to continue
@@ -68,10 +70,14 @@ impl Web3Connections {
 
         match self.block_numbers.entry(*block_num) {
             Entry::Occupied(mut x) => {
-                x.get_mut().push(*block_hash);
+                let old = x.insert(*block_hash);
+
+                todo!(
+                    "do something with the old hash. we need to update a bunch more block numbers"
+                )
             }
             Entry::Vacant(x) => {
-                x.insert(vec![*block_hash]);
+                x.insert(*block_hash);
             }
         }
 
@@ -157,30 +163,20 @@ impl Web3Connections {
 
         // first, try to get the hash from our cache
         if let Some(block_hash) = self.block_numbers.get(num) {
-            match block_hash.len() {
+            let block = self
-                0 => {
+                .block_hashes
-                    unimplemented!("block_numbers is broken")
+                .get(&block_hash)
-                }
+                .expect("block_numbers gave us this hash");
-                1 => {
-                    let block_hash = block_hash.get(0).expect("length was checked");
 
-                    let block = self
+            return Ok(block.clone());
-                        .block_hashes
-                        .get(block_hash)
-                        .expect("block_numbers gave us this hash");
-
-                    return Ok(block.clone());
-                }
-                _ => {
-                    // TODO: maybe the vec should be sorted by total difficulty.
-                    todo!("pick the block on the current consensus chain")
-                }
-            }
         }
 
         // block not in cache. we need to ask an rpc for it
         // but before we do any queries, be sure the requested block num exists
-        let head_block_num = self.head_block_num();
+        let head_block_num = self
+            .head_block_num()
+            .ok_or_else(|| anyhow::anyhow!("no servers in sync"))?;
+
         if num > &head_block_num {
             // TODO: i'm seeing this a lot when using ethspam. i dont know why though. i thought we delayed publishing
             // TODO: instead of error, maybe just sleep and try again?
@@ -252,16 +248,23 @@ impl Web3Connections {
         pending_tx_sender: &Option<broadcast::Sender<TxStatus>>,
     ) -> anyhow::Result<()> {
         // add the block to connection_heads
-        match (rpc_head_block.hash, rpc_head_block.number) {
+        let rpc_block_id = match (rpc_head_block.hash, rpc_head_block.number) {
             (Some(rpc_head_hash), Some(rpc_head_num)) => {
                 if rpc_head_num == U64::zero() {
                     debug!(%rpc, "still syncing");
 
                     connection_heads.remove(&rpc.name);
+
+                    None
                 } else {
                     connection_heads.insert(rpc.name.to_owned(), rpc_head_hash);
 
                     self.save_block(&rpc_head_block)?;
+
+                    Some(BlockId {
+                        hash: rpc_head_hash,
+                        num: rpc_head_num,
+                    })
                 }
             }
             _ => {
@@ -270,14 +273,15 @@ impl Web3Connections {
                 connection_heads.remove(&rpc.name);
 
                 // don't return yet! self.synced_connections likely needs an update
+                None
             }
-        }
+        };
 
         // iterate the rpc_map to find the highest_work_block
         let mut checked_heads = HashSet::new();
         let mut highest_work_block: Option<Ref<H256, ArcBlock>> = None;
 
-        for (_rpc_name, rpc_head_hash) in connection_heads.iter() {
+        for rpc_head_hash in connection_heads.values() {
             if checked_heads.contains(rpc_head_hash) {
                 continue;
             }
@@ -318,11 +322,11 @@ impl Web3Connections {
         };
 
         // track names so we don't check the same node multiple times
-        let mut consensus_names: HashSet<&String> = HashSet::new();
+        let mut heavy_names: HashSet<&String> = HashSet::new();
         // track rpcs so we can build a new SyncedConnections
-        let mut consensus_rpcs: Vec<&Arc<Web3Connection>> = vec![];
+        let mut heavy_rpcs: Vec<&Arc<Web3Connection>> = vec![];
         // a running total of the soft limits covered by the rpcs
-        let mut consensus_sum_soft_limit: u32 = 0;
+        let mut heavy_sum_soft_limit: u32 = 0;
 
         // check the highest work block and its parents for a set of rpcs that can serve our request load
         // TODO: loop for how many parent blocks? we don't want to serve blocks that are too far behind
@@ -331,7 +335,7 @@ impl Web3Connections {
             let highest_work_hash = highest_work_block.hash.as_ref().unwrap();
 
             for (rpc_name, rpc_head_hash) in connection_heads.iter() {
-                if consensus_names.contains(rpc_name) {
+                if heavy_names.contains(rpc_name) {
                     // this block is already included
                     continue;
                 }
@@ -339,9 +343,9 @@ impl Web3Connections {
                 // TODO: does all_simple_paths make this check?
                 if rpc_head_hash == highest_work_hash {
                     if let Some(rpc) = self.conns.get(rpc_name) {
-                        consensus_names.insert(rpc_name);
+                        heavy_names.insert(rpc_name);
-                        consensus_rpcs.push(rpc);
+                        heavy_rpcs.push(rpc);
-                        consensus_sum_soft_limit += rpc.soft_limit;
+                        heavy_sum_soft_limit += rpc.soft_limit;
                     }
                     continue;
                 }
@@ -362,21 +366,21 @@ impl Web3Connections {
 
                 if is_connected {
                     if let Some(rpc) = self.conns.get(rpc_name) {
-                        consensus_rpcs.push(rpc);
+                        heavy_rpcs.push(rpc);
-                        consensus_sum_soft_limit += rpc.soft_limit;
+                        heavy_sum_soft_limit += rpc.soft_limit;
                     }
                 }
             }
 
             // TODO: min_sum_soft_limit as a percentage of total_soft_limit?
             // let min_sum_soft_limit = total_soft_limit / self.min_sum_soft_limit;
-            if consensus_sum_soft_limit >= self.min_sum_soft_limit {
+            if heavy_sum_soft_limit >= self.min_sum_soft_limit {
                 // success! this block has enough nodes on it
                 break;
             }
             // else, we need to try the parent block
 
-            trace!(%consensus_sum_soft_limit, ?highest_work_hash, "avoiding thundering herd");
+            trace!(%heavy_sum_soft_limit, ?highest_work_hash, "avoiding thundering herd");
 
             // // TODO: this automatically queries for parents, but need to rearrange lifetimes to make an await work here
             // highest_work_block = self
@@ -389,9 +393,9 @@ impl Web3Connections {
                 None => {
                     warn!(
                         "ran out of parents to check. soft limit only {}/{}: {}%",
-                        consensus_sum_soft_limit,
+                        heavy_sum_soft_limit,
                         self.min_sum_soft_limit,
-                        consensus_sum_soft_limit * 100 / self.min_sum_soft_limit
+                        heavy_sum_soft_limit * 100 / self.min_sum_soft_limit
                     );
                     break;
                 }
@@ -403,29 +407,34 @@ impl Web3Connections {
         // unlock self.blockchain_graphmap
         drop(blockchain_guard);
 
-        let soft_limit_met = consensus_sum_soft_limit >= self.min_sum_soft_limit;
+        let soft_limit_met = heavy_sum_soft_limit >= self.min_sum_soft_limit;
-        let num_synced_rpcs = consensus_rpcs.len() as u32;
+        let num_synced_rpcs = heavy_rpcs.len() as u32;
 
         let new_synced_connections = if soft_limit_met {
-            // we have a consensus large enough to serve traffic
+            // we have a heavy large enough to serve traffic
             let head_block_hash = highest_work_block.hash.unwrap();
             let head_block_num = highest_work_block.number.unwrap();
 
             if num_synced_rpcs < self.min_synced_rpcs {
-                trace!(hash=%head_block_hash, num=?head_block_num, "not enough rpcs are synced to advance");
+                // TODO: warn is too loud. if we are first starting, this is expected to happen
+                warn!(hash=%head_block_hash, num=?head_block_num, "not enough rpcs are synced to advance");
 
-                return Ok(());
+                SyncedConnections::default()
             } else {
                 // TODO: wait until at least most of the rpcs have given their initial block?
                 // otherwise, if there is a syncing node that is fast, our first head block might not be good
                 // TODO: have a configurable "minimum rpcs" number that we can set
 
                 // TODO: sort by weight and soft limit? do we need an IndexSet, or is a Vec fine?
-                let conns = consensus_rpcs.into_iter().cloned().collect();
+                let conns = heavy_rpcs.into_iter().cloned().collect();
+
+                let head_block_id = BlockId {
+                    hash: head_block_hash,
+                    num: head_block_num,
+                };
 
                 SyncedConnections {
-                    head_block_num,
+                    head_block_id: Some(head_block_id),
-                    head_block_hash,
                     conns,
                 }
             }
@@ -438,36 +447,71 @@ impl Web3Connections {
             SyncedConnections::default()
         };
 
-        let consensus_block_hash = new_synced_connections.head_block_hash;
+        let heavy_block_id = new_synced_connections.head_block_id.clone();
-        let consensus_block_num = new_synced_connections.head_block_num;
         let new_synced_connections = Arc::new(new_synced_connections);
         let num_connection_heads = connection_heads.len();
-        let total_rpcs = self.conns.len();
+        let total_conns = self.conns.len();
 
         let old_synced_connections = self.synced_connections.swap(new_synced_connections);
 
-        let old_head_hash = old_synced_connections.head_block_hash;
+        match (&old_synced_connections.head_block_id, &heavy_block_id) {
-
+            (None, None) => warn!("no servers synced"),
-        if rpc_head_block.hash.is_some() && Some(consensus_block_hash) != rpc_head_block.hash {
+            (None, Some(heavy_block_id)) => {
-            info!(new=%rpc_head_block.hash.unwrap(), new_num=?rpc_head_block.number.unwrap(), consensus=%consensus_block_hash, num=%consensus_block_num, %rpc, "non consensus head");
+                debug!(block=%heavy_block_id, %rpc, "first consensus head");
-            // TODO: anything else to do? maybe warn if these blocks are very far apart or forked for an extended period of time
+            }
-            // TODO: if there is any non-consensus head log how many nodes are on it
+            (Some(_), None) => warn!("no longer synced!"),
+            (Some(old_block_id), Some(heavy_block_id)) => {
+                match heavy_block_id.num.cmp(&old_block_id.num) {
+                    Ordering::Equal => {
+                        todo!("handle equal")
+                    }
+                    Ordering::Less => {
+                        todo!("handle less")
+                    }
+                    Ordering::Greater => {
+                        todo!("handle greater")
+                    }
+                }
+            }
         }
+        /*
+        if old_synced_connections.head_block_id.is_none() && rpc_head_block.hash.is_some() {
+            // this is fine. we have our first hash
+        } else if rpc_head_block.hash.is_some()
+            && old_synced_connections.head_block_id.is_some()
+            && old_synced_connections
+                .head_block_id
+                .as_ref()
+                .map_ok(|x| x.num)
+                != rpc_head_block.hash
+        {
+            info!(new=%rpc_head_block.hash.unwrap(), new_num=?rpc_head_block.number.unwrap(), heavy=?heavy_block_id, %rpc, "non heavy head");
+            // TODO: anything else to do? maybe warn if these blocks are very far apart or forked for an extended period of time
+            // TODO: if there is any non-heavy head log how many nodes are on it
+        } */
 
-        if consensus_block_hash == old_head_hash {
+        /*
-            debug!(hash=%consensus_block_hash, num=%consensus_block_num, limit=%consensus_sum_soft_limit, %rpc, "cur consensus head {}/{}/{}", num_synced_rpcs, num_connection_heads, total_rpcs);
+        if heavy_block_num == U64::zero {
+            warn!(?soft_limit_met, %heavy_block_hash, %old_head_hash, %rpc, "NO heavy head  {}/{}/{}", num_synced_rpcs, num_connection_heads, total_rpcs)
+        } else if heavy_block_hash == old_head_hash {
+            debug!(hash=%heavy_block_hash, num=%heavy_block_num, limit=%heavy_sum_soft_limit, %rpc, "cur heavy head {}/{}/{}", num_synced_rpcs, num_connection_heads, total_rpcs);
         } else if soft_limit_met {
             // TODO: if new's parent is not old, warn?
 
-            debug!(hash=%consensus_block_hash, num=%consensus_block_num, limit=%consensus_sum_soft_limit, %rpc, "NEW consensus head {}/{}/{}", num_synced_rpcs, num_connection_heads, total_rpcs);
+            debug!(hash=%heavy_block_hash, num=%heavy_block_num, limit=%heavy_sum_soft_limit, %rpc, "NEW heavy head {}/{}/{}", num_synced_rpcs, num_connection_heads, total_rpcs);
 
             // the head hash changed. forward to any subscribers
             head_block_sender.send(highest_work_block)?;
 
             // TODO: do something with pending_tx_sender
         } else {
-            warn!(?soft_limit_met, %consensus_block_hash, %old_head_hash, %rpc, "NO consensus head  {}/{}/{}", num_synced_rpcs, num_connection_heads, total_rpcs)
+            // TODO: i don't think we can get here
+            warn!(?soft_limit_met, %heavy_block_id, %old_head_hash, %rpc, "NO heavy head  {}/{}/{}", num_synced_rpcs, num_connection_heads, total_rpcs)
         }
+        */
+
+        // TODO: the head hash changed. forward to any subscribers
+        head_block_sender.send(highest_work_block)?;
 
         Ok(())
     }

web3_proxy/src/rpcs/connections.rs

@@ -34,14 +34,15 @@ use tracing::{error, info, instrument, trace, warn};
 /// A collection of web3 connections. Sends requests either the current best server or all servers.
 #[derive(From)]
 pub struct Web3Connections {
-    pub(super) conns: HashMap<String, Arc<Web3Connection>>,
+    pub(super) inner: HashMap<String, Arc<Web3Connection>>,
     /// any requests will be forwarded to one (or more) of these connections
     pub(super) synced_connections: ArcSwap<SyncedConnections>,
     pub(super) pending_transactions: Arc<DashMap<TxHash, TxStatus>>,
     /// TODO: this map is going to grow forever unless we do some sort of pruning. maybe store pruned in redis?
     /// all blocks, including orphans
     pub(super) block_hashes: BlockHashesMap,
-    pub(super) block_numbers: DashMap<U64, Vec<H256>>,
+    /// blocks on the heaviest chain
+    pub(super) block_numbers: DashMap<U64, H256>,
     /// TODO: this map is going to grow forever unless we do some sort of pruning. maybe store pruned in redis?
     /// TODO: what should we use for edges?
     pub(super) blockchain_graphmap: RwLock<DiGraphMap<H256, u32>>,
@@ -168,7 +169,7 @@ impl Web3Connections {
         let synced_connections = SyncedConnections::default();
 
         let connections = Arc::new(Self {
-            conns: connections,
+            inner: connections,
             synced_connections: ArcSwap::new(Arc::new(synced_connections)),
             pending_transactions,
             block_hashes: Default::default(),
@@ -198,7 +199,7 @@ impl Web3Connections {
     }
 
     pub fn get(&self, conn_name: &str) -> Option<&Arc<Web3Connection>> {
-        self.conns.get(conn_name)
+        self.inner.get(conn_name)
     }
 
     /// subscribe to blocks and transactions from all the backend rpcs.
@@ -349,7 +350,7 @@ impl Web3Connections {
         // TODO: we are going to be checking "has_block_data" a lot now. i think we pretty much always have min_block_needed now that we override "latest"
         let mut synced_rpcs: Vec<Arc<Web3Connection>> =
             if let Some(min_block_needed) = min_block_needed {
-                self.conns
+                self.inner
                     .values()
                     .filter(|x| !skip.contains(x))
                     .filter(|x| x.has_block_data(min_block_needed))
@@ -435,7 +436,7 @@ impl Web3Connections {
         // TODO: with capacity?
         let mut selected_rpcs = vec![];
 
-        for connection in self.conns.values() {
+        for connection in self.inner.values() {
             if let Some(min_block_needed) = min_block_needed {
                 if !connection.has_block_data(min_block_needed) {
                     continue;
@@ -476,7 +477,7 @@ impl Web3Connections {
 
         // TODO: maximum retries?
         loop {
-            if skip_rpcs.len() == self.conns.len() {
+            if skip_rpcs.len() == self.inner.len() {
                 break;
             }
             match self
@@ -623,7 +624,7 @@ impl fmt::Debug for Web3Connections {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         // TODO: the default formatter takes forever to write. this is too quiet though
         f.debug_struct("Web3Connections")
-            .field("conns", &self.conns)
+            .field("conns", &self.inner)
             .finish_non_exhaustive()
     }
 }
@@ -633,7 +634,7 @@ impl Serialize for Web3Connections {
     where
         S: Serializer,
     {
-        let conns: Vec<&Web3Connection> = self.conns.iter().map(|x| x.1.as_ref()).collect();
+        let conns: Vec<&Web3Connection> = self.inner.iter().map(|x| x.1.as_ref()).collect();
 
         let mut state = serializer.serialize_struct("Web3Connections", 2)?;
         state.serialize_field("conns", &conns)?;

web3_proxy/src/rpcs/synced_connections.rs

@@ -1,3 +1,4 @@
+use super::blockchain::BlockId;
 use super::connection::Web3Connection;
 use super::connections::Web3Connections;
 use ethers::prelude::{H256, U64};
@@ -11,8 +12,7 @@ use std::sync::Arc;
 #[derive(Clone, Default, Serialize)]
 pub struct SyncedConnections {
     // TODO: store ArcBlock instead?
-    pub(super) head_block_num: U64,
+    pub(super) head_block_id: Option<BlockId>,
-    pub(super) head_block_hash: H256,
     // TODO: this should be able to serialize, but it isn't
     #[serde(skip_serializing)]
     pub(super) conns: IndexSet<Arc<Web3Connection>>,
@@ -23,29 +23,31 @@ impl fmt::Debug for SyncedConnections {
         // TODO: the default formatter takes forever to write. this is too quiet though
         // TODO: print the actual conns?
         f.debug_struct("SyncedConnections")
-            .field("head_num", &self.head_block_num)
+            .field("head_block_id", &self.head_block_id)
-            .field("head_hash", &self.head_block_hash)
             .field("num_conns", &self.conns.len())
             .finish_non_exhaustive()
     }
 }
 
 impl Web3Connections {
-    pub fn head_block(&self) -> (U64, H256) {
+    pub fn head_block_id(&self) -> Option<BlockId> {
-        let synced_connections = self.synced_connections.load();
+        self.synced_connections.load().head_block_id.clone()
-
-        (
-            synced_connections.head_block_num,
-            synced_connections.head_block_hash,
-        )
     }
 
-    pub fn head_block_hash(&self) -> H256 {
+    pub fn head_block_hash(&self) -> Option<H256> {
-        self.synced_connections.load().head_block_hash
+        self.synced_connections
+            .load()
+            .head_block_id
+            .as_ref()
+            .map(|head_block_id| head_block_id.hash)
     }
 
-    pub fn head_block_num(&self) -> U64 {
+    pub fn head_block_num(&self) -> Option<U64> {
-        self.synced_connections.load().head_block_num
+        self.synced_connections
+            .load()
+            .head_block_id
+            .as_ref()
+            .map(|head_block_id| head_block_id.num)
     }
 
     pub fn synced(&self) -> bool {