Due to an application error, our replication stopped for 5 days (over Easter). After the problem was solved, the replication was supposed to catch up, which turned out to be very slow. All the usual tricks (innodb_flush_log_at_trx_commit, sync_binlog, etc.) had already been exhausted. So we tried our hand at parallel replication of the MariaDB server.
Parallel replication is deactivated by default:
SQL> SHOW GLOBAL VARIABLES LIKE '%parallel%';
+-------------------------------+------------+
| …
