diff --git a/internal/indexcoord/meta_table.go b/internal/indexcoord/meta_table.go
index 8a1618b484..2c2df06b30 100644
--- a/internal/indexcoord/meta_table.go
+++ b/internal/indexcoord/meta_table.go
@@ -90,6 +90,7 @@ func (mt *metaTable) reloadFromKV() error {
 	return nil
 }
 
+// saveIndexMeta saves the index meta to ETCD.
 // metaTable.lock.Lock() before call this function
 func (mt *metaTable) saveIndexMeta(meta *Meta) error {
 	value, err := proto.Marshal(meta.indexMeta)