diff --git a/internal/util/rocksmq/client/rocksmq/reader_impl.go b/internal/util/rocksmq/client/rocksmq/reader_impl.go
index 18ad4748e3..8bb2507ec1 100644
--- a/internal/util/rocksmq/client/rocksmq/reader_impl.go
+++ b/internal/util/rocksmq/client/rocksmq/reader_impl.go
@@ -15,6 +15,7 @@ import (
 	"context"
 )
 
+// reader contains main options for rocksmq, and can only be set when newReader
 type reader struct {
 	c                       *client
 	topic                   string