diff --git a/internal/distributed/datanode/service.go b/internal/distributed/datanode/service.go
index 958a23301f..6ecc70efae 100644
--- a/internal/distributed/datanode/service.go
+++ b/internal/distributed/datanode/service.go
@@ -188,6 +188,7 @@ func (s *Server) Stop() error {
 	return nil
 }
 
+// init initializes Datanode's grpc service.
 func (s *Server) init() error {
 	ctx := context.Background()
 	Params.Init()