diff --git a/src/sql/ob_end_trans_callback.cpp b/src/sql/ob_end_trans_callback.cpp
index 35e003a98e..1fd466c548 100644
--- a/src/sql/ob_end_trans_callback.cpp
+++ b/src/sql/ob_end_trans_callback.cpp
@@ -61,6 +61,9 @@ void ObEndTransAsyncCallback::callback(int cb_param, const transaction::ObTransI
 void ObEndTransAsyncCallback::callback(int cb_param)
 {
   sql::ObSQLSessionInfo *session_info = mysql_end_trans_cb_.get_sess_info_ptr();
+  // Add ASH flags to async commit of transactions
+  // In the start of async commit in func named ` ObSqlTransControl::do_end_trans_() `,
+  // set the ash flag named  `in_committing_` to true.
   if (NULL != session_info) {
     ObActiveSessionGuard::setup_ash(session_info->get_ash_stat());
     ObActiveSessionGuard::get_stat().in_committing_ = false;
diff --git a/src/sql/ob_sql_trans_control.cpp b/src/sql/ob_sql_trans_control.cpp
index 5bdc313305..7b7b1022c3 100644
--- a/src/sql/ob_sql_trans_control.cpp
+++ b/src/sql/ob_sql_trans_control.cpp
@@ -456,6 +456,9 @@ int ObSqlTransControl::do_end_trans_(ObSQLSessionInfo *session,
         LOG_WARN("fail to inc session ref", K(ret));
       } else {
         callback->handout();
+        // Add ASH flags to async commit of transactions
+        // In the end of async commit in func named ` ObEndTransAsyncCallback::callback() `,
+        // set the ash flag named  `in_committing_` to false.
         ObActiveSessionGuard::get_stat().in_committing_ = true;
         if(OB_FAIL(txs->submit_commit_tx(*tx_ptr, expire_ts, *callback, &trace_info))) {
           LOG_WARN("submit commit tx fail", K(ret), KP(callback), K(expire_ts), KPC(tx_ptr));