diff --git a/internal/querycoord/cluster.go b/internal/querycoord/cluster.go
index 60690b9a003c9c5f1581b080885dc96c92c09232..64c847bb4fc0a8409fe1dccaf24ade0251ec75f0 100644
--- a/internal/querycoord/cluster.go
+++ b/internal/querycoord/cluster.go
@@ -726,7 +726,7 @@ func (c *queryNodeCluster) isOnline(nodeID int64) (bool, error) {
 		return node.isOnline(), nil
 	}
 
-	return false, fmt.Errorf("IsOnline: query node %d not exist", nodeID)
+	return false, fmt.Errorf("isOnline: query node %d not exist", nodeID)
 }
 
 //func (c *queryNodeCluster) printMeta() {