diff --git a/docs/developer_guides/chap09_data_coord.md b/docs/developer_guides/chap09_data_coord.md
index 85060376e3..4425c4b3b6 100644
--- a/docs/developer_guides/chap09_data_coord.md
+++ b/docs/developer_guides/chap09_data_coord.md
@@ -282,6 +282,10 @@ type DataNode interface {
 
 	WatchDmChannels(ctx context.Context, req *datapb.WatchDmChannelsRequest) (*commonpb.Status, error)
 	FlushSegments(ctx context.Context, req *datapb.FlushSegmentsRequest) (*commonpb.Status, error)
+  // GetMetrics gets the metrics about DataNode.
+	GetMetrics(ctx context.Context, req *milvuspb.GetMetricsRequest) (*milvuspb.GetMetricsResponse, error)
+
+	Compaction(ctx context.Context, req *datapb.CompactionPlan) (*commonpb.Status, error)
 }
 ```