From 993b84408bc2b271fd428c5a6d2677a969564b3d Mon Sep 17 00:00:00 2001
From: Chris Evanko <106608356+cjeva10@users.noreply.github.com>
Date: Mon, 24 Jul 2023 17:42:59 -0400
Subject: [PATCH] feat: add canonicalization latency metric (#3865)

---
 crates/consensus/beacon/src/engine/metrics.rs | 10 ++++++-
 crates/consensus/beacon/src/engine/mod.rs     | 30 +++++++++++++++++--
 2 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/crates/consensus/beacon/src/engine/metrics.rs b/crates/consensus/beacon/src/engine/metrics.rs
index 04080e93be..66a95dc578 100644
--- a/crates/consensus/beacon/src/engine/metrics.rs
+++ b/crates/consensus/beacon/src/engine/metrics.rs
@@ -1,5 +1,5 @@
 use reth_metrics::{
-    metrics::{self, Counter, Gauge},
+    metrics::{self, Counter, Gauge, Histogram},
     Metrics,
 };
 
@@ -15,6 +15,14 @@ pub(crate) struct EngineMetrics {
     pub(crate) new_payload_messages: Counter,
     /// The number of times the pruner was run.
     pub(crate) pruner_runs: Counter,
+    /// Latency for making canonical already canonical block
+    pub(crate) make_canonical_already_canonical_latency: Histogram,
+    /// Latency for making canonical committed block
+    pub(crate) make_canonical_committed_latency: Histogram,
+    /// Latency for making canonical returns error
+    pub(crate) make_canonical_error_latency: Histogram,
+    /// Latency for all making canonical results
+    pub(crate) make_canonical_latency: Histogram,
 }
 
 /// Metrics for the `EngineSyncController`.
diff --git a/crates/consensus/beacon/src/engine/mod.rs b/crates/consensus/beacon/src/engine/mod.rs
index 35ecd356a2..7c74bc3957 100644
--- a/crates/consensus/beacon/src/engine/mod.rs
+++ b/crates/consensus/beacon/src/engine/mod.rs
@@ -12,7 +12,7 @@ use reth_db::database::Database;
 use reth_interfaces::{
     blockchain_tree::{
         error::{InsertBlockError, InsertBlockErrorKind},
-        BlockStatus, BlockchainTreeEngine, InsertPayloadOk,
+        BlockStatus, BlockchainTreeEngine, CanonicalOutcome, InsertPayloadOk,
     },
     consensus::ForkchoiceState,
     executor::{BlockExecutionError, BlockValidationError},
@@ -39,6 +39,7 @@ use std::{
     pin::Pin,
     sync::Arc,
     task::{Context, Poll},
+    time::Instant,
 };
 use tokio::sync::{
     mpsc,
@@ -628,7 +629,10 @@ where
             return Ok(OnForkChoiceUpdated::syncing())
         }
 
-        let status = match self.blockchain.make_canonical(&state.head_block_hash) {
+        let start = Instant::now();
+        let make_canonical_result = self.blockchain.make_canonical(&state.head_block_hash);
+        self.record_make_canonical_latency(start, &make_canonical_result);
+        let status = match make_canonical_result {
             Ok(outcome) => {
                 if !outcome.is_already_canonical() {
                     debug!(target: "consensus::engine", hash=?state.head_block_hash, number=outcome.header().number, "canonicalized new head");
@@ -684,6 +688,28 @@ where
         Ok(OnForkChoiceUpdated::valid(status))
     }
 
+    /// Record latency metrics for one call to make a block canonical
+    /// Takes start time of the call and result of the make canonical call
+    ///
+    /// Handles cases for error, already canonical and commmitted blocks
+    fn record_make_canonical_latency(
+        &self,
+        start: Instant,
+        outcome: &Result<CanonicalOutcome, Error>,
+    ) {
+        let elapsed = start.elapsed();
+        self.metrics.make_canonical_latency.record(elapsed);
+        match outcome {
+            Ok(CanonicalOutcome::AlreadyCanonical { .. }) => {
+                self.metrics.make_canonical_already_canonical_latency.record(elapsed)
+            }
+            Ok(CanonicalOutcome::Committed { .. }) => {
+                self.metrics.make_canonical_committed_latency.record(elapsed)
+            }
+            Err(_) => self.metrics.make_canonical_error_latency.record(elapsed),
+        }
+    }
+
     /// Ensures that the given forkchoice state is consistent, assuming the head block has been
     /// made canonical. This takes a status as input, and will only perform consistency checks if
     /// the input status is VALID.