Make --lock-ddl and --lock-ddl-per-table mutually exclusive

[Shahriyar Rzayev]

If you use both --lock-ddl and --lock-ddl-per-table the result will the locks will wait and backup will not be completed:

xtrabackup --defaults-file=/home/shahriyar.rzaev/sandboxes/rsandbox_Percona-Server-5_7_18/master/my.sandbox.cnf --user=msandbox --password='msandbox' --target-dir=/home/shahriyar.rzaev/backup_dir/ps_5.7_master/full/2017-07-26_11-24-08 --backup --host=127.0.0.1 --port=20393 --binlog-info=AUTO --galera-info --parallel 4 --check-privileges --no-version-check --lock-ddl --lock-ddl-per-table

show processlist;
+-----+----------+-----------------+------+---------+------+---------------------------------+-------------------------------+-----------+---------------+
| Id | User | Host | db | Command | Time | State | Info | Rows_sent | Rows_examined |
+-----+----------+-----------------+------+---------+------+---------------------------------+-------------------------------+-----------+---------------+
| 7 | root | localhost | NULL | Query | 0 | starting | show processlist | 0 | 0 |
| 225 | msandbox | localhost:46153 | NULL | Sleep | 177 | | NULL | 1 | 116 |
| 226 | root | localhost | NULL | Query | 176 | Waiting for backup lock | drop table if exists db2.sb1 | 0 | 0 |
| 227 | msandbox | localhost:46154 | NULL | Query | 175 | Waiting for table metadata lock | SELECT * FROM db2.sb1 LIMIT 1 | 0 | 0 |
+-----+----------+-----------------+------+---------+------+---------------------------------+-------------------------------+-----------+---------------+
4 rows in set (0.00 sec)

The best is to make these options to be mutually exclusive.

[Shahriyar Rzayev (rzayev-sehriyar)]

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PXB-792