diff --git a/internal/util/metricsinfo/topology.go b/internal/util/metricsinfo/topology.go
index 75bb67f83e..f3d34268ff 100644
--- a/internal/util/metricsinfo/topology.go
+++ b/internal/util/metricsinfo/topology.go
@@ -113,6 +113,7 @@ type ConnectionEdge struct {
 	TargetType          ConnectionTargetType `json:"target_type"` // RootCoord, DataCoord ...
 }
 
+// SystemTopologyNode is a node in system topogoly graph.
 type SystemTopologyNode struct {
 	Identifier int              `json:"identifier"` // unique in the SystemTopology graph
 	Connected  []ConnectionEdge `json:"connected"`