Fix race condition in active user (#6773)

SungJin1212 · web-flow · commit cf407e4f14bf · 2025-05-29T21:21:15.000-07:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -46,6 +46,7 @@
 * [BUGFIX] Query Frontend: Fix query frontend per `user` metrics clean up. #6698
 * [BUGFIX] Add `__markers__` tenant ID validation. #6761
 * [BUGFIX] Ring: Fix nil pointer exception when token is shared. #6768
+* [BUGFIX] Fix race condition in active user. #6773
 
 ## 1.19.0 2025-02-27
 
diff --git a/pkg/util/active_user.go b/pkg/util/active_user.go
@@ -95,8 +95,8 @@ func (m *ActiveUsers) PurgeInactiveUsers(deadline int64) []string {
 }
 
 func (m *ActiveUsers) ActiveUsers(deadline int64) []string {
-	active := make([]string, 0, len(m.timestamps))
 	m.mu.RLock()
+	active := make([]string, 0, len(m.timestamps))
 	defer m.mu.RUnlock()
 	for userID, ts := range m.timestamps {
 		if ts.Load() > deadline {

Original file line number	Diff line number	Diff line change
`@@ -95,8 +95,8 @@ func (m *ActiveUsers) PurgeInactiveUsers(deadline int64) []string {`
`95`	`95`	`}`
`96`	`96`
`97`	`97`	`func (m *ActiveUsers) ActiveUsers(deadline int64) []string {`
`98`		`- active := make([]string, 0, len(m.timestamps))`
`99`	`98`	`m.mu.RLock()`
	`99`	`+ active := make([]string, 0, len(m.timestamps))`
`100`	`100`	`defer m.mu.RUnlock()`
`101`	`101`	`for userID, ts := range m.timestamps {`
`102`	`102`	`if ts.Load() > deadline {`