diff --git a/internal/querynode/data_sync_service.go b/internal/querynode/data_sync_service.go
index 90eb76ec52..660ae900dd 100644
--- a/internal/querynode/data_sync_service.go
+++ b/internal/querynode/data_sync_service.go
@@ -138,6 +138,7 @@ func (dsService *dataSyncService) getCollectionDeltaFlowGraphs(collectionID Uniq
 	return tmpFGs, nil
 }
 
+// startCollectionFlowGraph starts the collection flow graph by collectionID
 func (dsService *dataSyncService) startCollectionFlowGraph(collectionID UniqueID, vChannels []string) error {
 	dsService.mu.Lock()
 	defer dsService.mu.Unlock()