diff --git a/internal/datacoord/handler.go b/internal/datacoord/handler.go
index 66b7c4bfc3..77d7c8724c 100644
--- a/internal/datacoord/handler.go
+++ b/internal/datacoord/handler.go
@@ -13,6 +13,7 @@ import (
 
 // Handler handles some channel method for ChannelManager
 type Handler interface {
+	// GetVChanPositions gets the information recovery needed of a channel
 	GetVChanPositions(channel string, collectionID UniqueID, partitionID UniqueID) *datapb.VchannelInfo
 	CheckShouldDropChannel(channel string) bool
 }