MDEV-17308 mariabackup to use the BACKUP statement instead of FTWRL

extra/mariabackup/backup_mysql.cc

@@ -971,28 +971,10 @@ lock_tables(MYSQL *connection)
 	}
 
 	if (opt_lock_ddl_per_table) {
+		/* TODO : Remove after MDEV-17772 is fixed */
 		start_mdl_waiters_killer();
 	}
 
-	if (!opt_lock_wait_timeout && !opt_kill_long_queries_timeout) {
-
-		/* We do first a FLUSH TABLES. If a long update is running, the
-		FLUSH TABLES will wait but will not stall the whole mysqld, and
-		when the long update is done the FLUSH TABLES WITH READ LOCK
-		will start and succeed quickly. So, FLUSH TABLES is to lower
-		the probability of a stage where both mysqldump and most client
-		connections are stalled. Of course, if a second long update
-		starts between the two FLUSHes, we have that bad stall.
-
-		Option lock_wait_timeout serve the same purpose and is not
-		compatible with this trick.
-		*/
-
-		msg_ts("Executing FLUSH NO_WRITE_TO_BINLOG TABLES...\n");
-
-		xb_mysql_query(connection,
-			       "FLUSH NO_WRITE_TO_BINLOG TABLES", false);
-	}
 
 	if (opt_lock_wait_timeout) {
 		if (!wait_for_no_updates(connection, opt_lock_wait_timeout,
@@ -1001,7 +983,7 @@ lock_tables(MYSQL *connection)
 		}
 	}
 
-	msg_ts("Executing FLUSH TABLES WITH READ LOCK...\n");
+	msg_ts("Acquiring BACKUP LOCKS...\n");
 
 	if (opt_kill_long_queries_timeout) {
 		start_query_killer();
@@ -1012,9 +994,13 @@ lock_tables(MYSQL *connection)
 				"SET SESSION wsrep_causal_reads=0", false);
 	}
 
-	xb_mysql_query(connection, "FLUSH TABLES WITH READ LOCK", false);
+	xb_mysql_query(connection, "BACKUP STAGE START", true);
+	//xb_mysql_query(connection, "BACKUP STAGE FLUSH", true);
+	//xb_mysql_query(connection, "BACKUP STAGE BLOCK_DDL", true);
+	xb_mysql_query(connection, "BACKUP STAGE BLOCK_COMMIT", true);
 
 	if (opt_lock_ddl_per_table) {
+		/* TODO : Remove after MDEV-17772 is fixed */
 		stop_mdl_waiters_killer();
 	}
 
@@ -1058,13 +1044,8 @@ unlock_all(MYSQL *connection)
 		os_thread_sleep(opt_debug_sleep_before_unlock * 1000);
 	}
 
-	if (binlog_locked) {
-		msg_ts("Executing UNLOCK BINLOG\n");
-		xb_mysql_query(connection, "UNLOCK BINLOG", false);
-	}
-
-	msg_ts("Executing UNLOCK TABLES\n");
-	xb_mysql_query(connection, "UNLOCK TABLES", false);
+	msg_ts("Executing BACKUP STAGE END\n");
+	xb_mysql_query(connection, "BACKUP STAGE END", false);
 
 	msg_ts("All tables unlocked\n");
 }

extra/mariabackup/xtrabackup.cc

@@ -474,9 +474,18 @@ DECLARE_THREAD(dbug_execute_in_new_connection)(void *arg)
 	dbug_thread_param_t *par= (dbug_thread_param_t *)arg;
 	int err = mysql_query(par->con, par->query);
 	int err_no = mysql_errno(par->con);
-	DBUG_ASSERT(par->expect_err == err);
-	if (err && par->expect_errno)
-		DBUG_ASSERT(err_no == par->expect_errno);
+	if(par->expect_err != err)
+	{
+		msg("FATAL: dbug_execute_in_new_connection : mysql_query '%s' returns %d, instead of expected %d",
+			par->query, err, par->expect_err);
+		_exit(1);
+	}
+	if (err && par->expect_errno && par->expect_errno != err_no)
+	{
+		msg("FATAL: dbug_execute_in_new_connection: mysql_query '%s' returns mysql_errno %d, instead of expected %d",
+			par->query, err_no, par->expect_errno);
+		_exit(1);
+	}
 	mysql_close(par->con);
 	mysql_thread_end();
 	os_event_t done = par->done_event;