diff --git a/src/gausskernel/storage/replication/syncrep.cpp b/src/gausskernel/storage/replication/syncrep.cpp
index a2fdf69b..6ae81d7b 100644
--- a/src/gausskernel/storage/replication/syncrep.cpp
+++ b/src/gausskernel/storage/replication/syncrep.cpp
@@ -623,6 +623,9 @@ bool SyncRepGetSyncRecPtr(XLogRecPtr *receivePtr, XLogRecPtr *writePtr, XLogRecP
      * or there are not enough synchronous standbys.
      * but in a particular scenario, when most_available_sync is true, primary only wait the alive sync standbys
      * if list_length(sync_standbys) doesn't satisfy t_thrd.syncrep_cxt.SyncRepConfig->num_sync.
+     * 
+     * All synchronous standbys are allowed to disconnect from the host
+     * only when the maximum available mode is on
      */
     if ((!(*am_sync) && check_am_sync) || t_thrd.syncrep_cxt.SyncRepConfig == NULL ||
         (!t_thrd.walsender_cxt.WalSndCtl->most_available_sync &&
diff --git a/src/gausskernel/storage/replication/walsender.cpp b/src/gausskernel/storage/replication/walsender.cpp
index b02c6993..8392f901 100644
--- a/src/gausskernel/storage/replication/walsender.cpp
+++ b/src/gausskernel/storage/replication/walsender.cpp
@@ -3209,6 +3209,9 @@ static int WalSndLoop(WalSndSendDataCallback send_data)
             } else if (t_thrd.syncrep_cxt.SyncRepConfig == NULL ||
                         (t_thrd.walsender_cxt.WalSndCtl->most_available_sync &&
                             list_length(SyncRepGetSyncStandbys(&amSync)) == 0)) {
+                /*
+                 * This step is used to deal with the situation that synchronous standbys are not set.
+                 */
                 ArchiveXlogOnStandby(t_thrd.walsender_cxt.MyWalSnd->flush);
             } else {
                 ereport(WARNING, (errcode(ERRCODE_WARNING),