diff --git a/src/rootserver/ob_root_service.cpp b/src/rootserver/ob_root_service.cpp
index c6259c185fb5faa0f3b23de1f7d2e28c9f47ed9a..8c278640a37792b886e6a1a583b710051d596237 100644
--- a/src/rootserver/ob_root_service.cpp
+++ b/src/rootserver/ob_root_service.cpp
@@ -7538,52 +7538,14 @@ int ObRootService::generate_stop_server_log_in_sync_dest_server_array(
   return ret;
 }
 
-int ObRootService::generate_log_in_sync_dest_server_buff(common::ObIAllocator& allocator,
-    const common::ObIArray<common::ObAddr>& dest_server_array, common::ObString& dest_server_buff)
-{
-  int ret = OB_SUCCESS;
-  if (OB_UNLIKELY(!inited_)) {
-    ret = OB_NOT_INIT;
-    LOG_WARN("not init", K(ret));
-  } else if (OB_UNLIKELY(dest_server_array.count() <= 0)) {
-    ret = OB_SERVER_NOT_ALIVE;  // dest_server_array is empty, although it can be processed, but still throw error
-    LOG_WARN("all server not alive", K(ret));
-  } else {
-    char* buf = NULL;
-    const int64_t buf_len = dest_server_array.count() * (MAX_IP_ADDR_LENGTH + 2) + 1;
-    if (OB_UNLIKELY(nullptr == (buf = static_cast<char*>(allocator.alloc(buf_len))))) {
-      ret = OB_ALLOCATE_MEMORY_FAILED;
-      LOG_WARN("fail to alloc buf", K(ret), K(buf));
-    } else {
-      int64_t pos = 0;
-      bool first = true;
-      MEMSET(static_cast<void*>(buf), 0, buf_len);
-      for (int64_t index = 0; OB_SUCC(ret) && index < dest_server_array.count(); ++index) {
-        const common::ObAddr& server = dest_server_array.at(index);
-        if (OB_FAIL(databuff_printf(buf, buf_len, pos, "%s", first ? "" : ","))) {
-          LOG_WARN("fail to do databuff printf", K(ret));
-        } else {
-          first = false;
-          pos += server.to_string(buf + pos, buf_len - pos);
-        }
-      }
-      if (OB_SUCC(ret)) {
-        dest_server_buff.assign_ptr(buf, pos);
-      }
-    }
-  }
-  return ret;
-}
-
 int ObRootService::check_is_log_sync(bool& is_log_sync, const common::ObIArray<ObAddr>& stop_server)
 {
   int ret = OB_SUCCESS;
-  ObArenaAllocator alloc;
   is_log_sync = true;
   common::ObZone zone; /*empty zone*/
   common::ObArray<common::ObAddr> alive_server_array;
   common::ObArray<common::ObAddr> dest_server_array;
-  common::ObString dest_server_buff;
+  ObSqlString sql;
   if (OB_UNLIKELY(!inited_)) {
     ret = OB_NOT_INIT;
     LOG_WARN("not init", K(ret));
@@ -7596,10 +7558,9 @@ int ObRootService::check_is_log_sync(bool& is_log_sync, const common::ObIArray<O
         K(alive_server_array),
         K(stop_server),
         K(dest_server_array));
-  } else if (OB_FAIL(generate_log_in_sync_dest_server_buff(alloc, dest_server_array, dest_server_buff))) {
-    LOG_WARN("fail to generate log in sync dest server buff", K(ret), K(dest_server_array), K(dest_server_buff));
+  } else if (OB_FAIL(generate_log_in_sync_sql(dest_server_array, sql))) {
+    LOG_WARN("fail to generate log in sync dest server buff", K(ret), K(dest_server_array), K(sql));
   } else {
-    ObSqlString sql;
     HEAP_VAR(ObMySQLProxy::MySQLResult, res)
     {
       sqlclient::ObMySQLResult* result = NULL;
@@ -7608,12 +7569,6 @@ int ObRootService::check_is_log_sync(bool& is_log_sync, const common::ObIArray<O
       // pay attention partition_idx actually is partition_id
       if (OB_FAIL(schema_service_->get_schema_guard(schema_guard))) {
         LOG_WARN("fail to get schema guard", K(ret));
-      } else if (OB_FAIL(sql.assign_fmt("SELECT table_id, partition_idx FROM %s WHERE is_in_sync = 0 and "
-                                        "is_offline = 0 and replica_type != 16 "
-                                        "and concat(svr_ip, \":\", svr_port) in (%s)",
-                     OB_ALL_VIRTUAL_CLOG_STAT_TNAME,
-                     dest_server_buff.ptr()))) {
-        LOG_WARN("assign_fmt failed", K(ret));
       } else if (OB_FAIL(sql_proxy_.read(res, sql.ptr()))) {
         LOG_WARN("execute sql failed", K(ret), K(sql));
       } else if (OB_ISNULL(result = res.get_result())) {
@@ -7836,6 +7791,48 @@ int ObRootService::admin_switch_replica_role(const obrpc::ObAdminSwitchReplicaRo
   return ret;
 }
 
+int ObRootService::generate_log_in_sync_sql(
+    const common::ObIArray<common::ObAddr> &dest_server_array, common::ObSqlString &sql)
+{
+  int ret = OB_SUCCESS;
+  sql.reset();
+  if (OB_UNLIKELY(!inited_)) {
+    ret = OB_NOT_INIT;
+    LOG_WARN("not init", KR(ret));
+  } else if (OB_UNLIKELY(dest_server_array.count() <= 0)) {
+    ret = OB_SERVER_NOT_ALIVE;  // all server not alive
+    LOG_WARN("all server not alive", KR(ret));
+  } else if (OB_FAIL(sql.assign_fmt("SELECT table_id, partition_idx FROM %s WHERE is_in_sync = 0 and "
+                                    "is_offline = 0 and replica_type != 16 "
+                                    "and (svr_ip, svr_port) in (",
+                 OB_ALL_VIRTUAL_CLOG_STAT_TNAME))) {
+    LOG_WARN("assign_fmt failed", KR(ret), K(sql));
+  } else {
+    for (int64_t i = 0; OB_SUCC(ret) && i < dest_server_array.count(); ++i) {
+      const common::ObAddr &addr = dest_server_array.at(i);
+      char ip_str[MAX_IP_PORT_LENGTH] = "";
+      if (0 != i) {
+        if (OB_FAIL(sql.append(","))) {
+          LOG_WARN("failed to append fmt sql", KR(ret), K(i), K(sql));
+        }
+      }
+      if (OB_FAIL(ret)) {
+      } else if (!addr.ip_to_string(ip_str, MAX_IP_PORT_LENGTH)) {
+        ret = OB_ERR_UNEXPECTED;
+        LOG_WARN("failed to ip to string", KR(ret), K(ip_str), K(addr));
+      } else if (OB_FAIL(sql.append_fmt("(\"%s\", %d)", ip_str, addr.get_port()))) {
+        LOG_WARN("failed to append fmt sql", KR(ret), K(i), K(ip_str), K(addr), K(sql));
+      }
+    }
+  }
+  if (OB_FAIL(ret)) {
+  } else if (OB_FAIL(sql.append(")"))) {
+    LOG_WARN("failed to append fmt sql", KR(ret), K(sql));
+  }
+  return ret;
+}
+
+
 int ObRootService::admin_switch_rs_role(const obrpc::ObAdminSwitchRSRoleArg& arg)
 {
   int ret = OB_SUCCESS;
diff --git a/src/rootserver/ob_root_service.h b/src/rootserver/ob_root_service.h
index 14e2c75cd816d2e50552c5a2ab8abfda5b05c20a..250387dd0b265e653ee9f5bad8bafebc2cbc4ec4 100644
--- a/src/rootserver/ob_root_service.h
+++ b/src/rootserver/ob_root_service.h
@@ -1166,16 +1166,15 @@ public:
   int logical_restore_partitions(const obrpc::ObRestorePartitionsArg& arg);
 
   int check_is_log_sync(bool& is_log_sync, const common::ObIArray<common::ObAddr>& stop_server);
+  int generate_log_in_sync_sql(const common::ObIArray<common::ObAddr> &dest_server_array, common::ObSqlString &sql);
   int generate_stop_server_log_in_sync_dest_server_array(const common::ObIArray<common::ObAddr>& alive_server_array,
       const common::ObIArray<common::ObAddr>& excluded_server_array,
       common::ObIArray<common::ObAddr>& dest_server_array);
-  int generate_log_in_sync_dest_server_buff(common::ObIAllocator& allocator,
-      const common::ObIArray<common::ObAddr>& dest_server_array, common::ObString& dest_server_buff);
   int log_nop_operation(const obrpc::ObDDLNopOpreatorArg& arg);
   int broadcast_schema(const obrpc::ObBroadcastSchemaArg& arg);
   int check_other_rs_exist(bool& is_other_rs_exist);
   ObRsGtsManager& get_rs_gts_manager()
-  {
+    {
     return rs_gts_manager_;
   }
   ObFreezeInfoManager& get_freeze_manager()