From 7d3948c8fe32a7624d7fafaf2561a1f8ac291e3f Mon Sep 17 00:00:00 2001
From: Paul Hauner <paul@paulhauner.com>
Date: Tue, 13 Sep 2022 17:19:27 +0000
Subject: [PATCH] Add metric for re-org distance (#3566)

## Issue Addressed

NA

## Proposed Changes

Add a metric to track the re-org distance.

## Additional Info

NA
---
 beacon_node/beacon_chain/src/canonical_head.rs | 4 ++++
 beacon_node/beacon_chain/src/metrics.rs        | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/beacon_node/beacon_chain/src/canonical_head.rs b/beacon_node/beacon_chain/src/canonical_head.rs
index 644364bc6..c9bd6db0e 100644
--- a/beacon_node/beacon_chain/src/canonical_head.rs
+++ b/beacon_node/beacon_chain/src/canonical_head.rs
@@ -1189,6 +1189,10 @@ fn detect_reorg<E: EthSpec>(
 
         metrics::inc_counter(&metrics::FORK_CHOICE_REORG_COUNT);
         metrics::inc_counter(&metrics::FORK_CHOICE_REORG_COUNT_INTEROP);
+        metrics::set_gauge(
+            &metrics::FORK_CHOICE_REORG_DISTANCE,
+            reorg_distance.as_u64() as i64,
+        );
         warn!(
             log,
             "Beacon chain re-org";
diff --git a/beacon_node/beacon_chain/src/metrics.rs b/beacon_node/beacon_chain/src/metrics.rs
index cad77a378..b454a6ff8 100644
--- a/beacon_node/beacon_chain/src/metrics.rs
+++ b/beacon_node/beacon_chain/src/metrics.rs
@@ -305,6 +305,10 @@ lazy_static! {
         "beacon_fork_choice_reorg_total",
         "Count of occasions fork choice has switched to a different chain"
     );
+    pub static ref FORK_CHOICE_REORG_DISTANCE: Result<IntGauge> = try_create_int_gauge(
+        "beacon_fork_choice_reorg_distance",
+        "The distance of each re-org of the fork choice algorithm"
+    );
     pub static ref FORK_CHOICE_REORG_COUNT_INTEROP: Result<IntCounter> = try_create_int_counter(
         "beacon_reorgs_total",
         "Count of occasions fork choice has switched to a different chain"