From 4f959f2611957d45790c1d7719f228bf109a2acb Mon Sep 17 00:00:00 2001
From: Roman Golov <golov-rg@yandex-team.ru>
Date: Tue, 17 Sep 2024 17:24:02 +0300
Subject: [PATCH] Fix concurrent map writes in metrics

---
 CHANGELOG.md      | 1 +
 metrics/driver.go | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ea3eba4e5..a9854d6a3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,4 @@
+* Fixed concurrent map writes in metrics
 * Renamed method at experimental API reader.PopBatchTx to reader.PopMessagesBatchTx
 
 ## v3.80.5
diff --git a/metrics/driver.go b/metrics/driver.go
index 014853b1d..50d56092d 100644
--- a/metrics/driver.go
+++ b/metrics/driver.go
@@ -2,6 +2,7 @@ package metrics
 
 import (
 	"strconv"
+	"sync"
 
 	"github.com/ydb-platform/ydb-go-sdk/v3/internal/repeater"
 	"github.com/ydb-platform/ydb-go-sdk/v3/internal/xerrors"
@@ -26,6 +27,7 @@ func driver(config Config) (t trace.Driver) {
 		az string
 	}
 	knownEndpoints := make(map[endpointKey]struct{})
+	endpointsMu := sync.RWMutex{}
 
 	t.OnConnInvoke = func(info trace.DriverConnInvokeStartInfo) func(trace.DriverConnInvokeDoneInfo) {
 		var (
@@ -104,6 +106,8 @@ func driver(config Config) (t trace.Driver) {
 
 		return func(info trace.DriverBalancerUpdateDoneInfo) {
 			if config.Details()&trace.DriverBalancerEvents != 0 {
+				endpointsMu.Lock()
+				defer endpointsMu.Unlock()
 				balancerUpdates.With(map[string]string{
 					"cause": eventType,
 				}).Inc()