Hi, before considering this as a bug wanted to ask in mailing list: I know that gtid_slave_pos table can have multiple entries, but (at least on 10.3.9 but maybe also earlier (just noticed now)) while running: slave_parallel_threads = 20 slave_parallel_mode = optimistic the table starts to grow continuously: MariaDB [mysql]> select count(*) from gtid_slave_pos; +----------+ | count(*) | +----------+ | 5577268 | +----------+ 1 row in set (1.553 sec) If I switch back to conservative mode it never goes above 2-3 rows even with the same 20 threads. Same happens also with gtid_pos_auto_engines - when in conservative each engine table has several records, once I switch to optimistic the gtid tables just grow. Is there something wrong with the purger? (something similar like in https://jira.mariadb.org/browse/MDEV-12147 ? ) rr