diff --git a/internal/distributed/datanode/service.go b/internal/distributed/datanode/service.go
index b289856897..97c08469cd 100644
--- a/internal/distributed/datanode/service.go
+++ b/internal/distributed/datanode/service.go
@@ -150,6 +150,7 @@ func (s *Server) Run() error {
 	return nil
 }
 
+// Stop stops Datanode's grpc service.
 func (s *Server) Stop() error {
 	log.Debug("Datanode stop", zap.String("Address", Params.Address))
 	if s.closer != nil {