diff --git a/src/main/java/com/netease/arctic/benchmark/ingestion/BaseCatalogSync.java b/src/main/java/com/netease/arctic/benchmark/ingestion/BaseCatalogSync.java
index c315b17..c019da3 100644
--- a/src/main/java/com/netease/arctic/benchmark/ingestion/BaseCatalogSync.java
+++ b/src/main/java/com/netease/arctic/benchmark/ingestion/BaseCatalogSync.java
@@ -44,7 +44,8 @@
 import java.util.function.Consumer;
 
 /**
- * Basic class for data ingestion
+ * Basic class for data ingestion, includes getting the table schema,
+ * monitoring the database data via flink cdc and inserting the database data into the data lake.
  */
 public abstract class BaseCatalogSync implements Consumer<CallContext> {
 
diff --git a/src/main/java/com/netease/arctic/benchmark/ingestion/MainRunner.java b/src/main/java/com/netease/arctic/benchmark/ingestion/MainRunner.java
index 4b7d097..a37fb5c 100644
--- a/src/main/java/com/netease/arctic/benchmark/ingestion/MainRunner.java
+++ b/src/main/java/com/netease/arctic/benchmark/ingestion/MainRunner.java
@@ -49,7 +49,8 @@
 import lombok.extern.slf4j.Slf4j;
 
 /**
- * Start-up class
+ * Start-up class, includes parsing configuration files, creating source and sink catalogs
+ * and calling synchronisation functions
  */
 @Slf4j
 public class MainRunner {