Andrei Elkin <andrei.elkin@mariadb.com> writes:

...

My question is if it is ok and by design that the event can continue running after the scheduler is stopped and even after the event is dropped? That

Should not be ok. The docs https://mariadb.com/kb/en/drop-event/

are explicit

Description This statement drops the event named event_name. The event immediately ceases being active, and is deleted completely from the server.

Thanks for the link, Andrei! Interesting, this doesn't seem to be how it works. This small test starts an event that runs for 3 seconds, but drops the event after 1 second: ----------------------------------------------------------------------- SET GLOBAL event_scheduler= OFF; CREATE TABLE t1(a INT); CREATE EVENT ev1 ON SCHEDULE EVERY 5 SECOND DO INSERT INTO t1 VALUES(SLEEP(3)); SET GLOBAL event_scheduler= ON; --sleep 1 SHOW FULL PROCESSLIST; SET GLOBAL event_scheduler= OFF; DROP EVENT ev1; SHOW FULL PROCESSLIST; --sleep 1 SHOW FULL PROCESSLIST; DROP TABLE t1; ----------------------------------------------------------------------- The already-started instance of the event happily continues to run after being dropped. I wonder if that's a bug, or if the documentation is wrong? And if it is a bug, if there are any use-after-free or similar memory issues with the event continuing to run after being dropped? Valgrind doesn't complain... ----------------------------------------------------------------------- SET GLOBAL event_scheduler= OFF; CREATE TABLE t1(a INT); CREATE EVENT ev1 ON SCHEDULE EVERY 5 SECOND DO INSERT INTO t1 VALUES(SLEEP(3)); Warnings: Warning 1105 Event scheduler is switched off, use SET GLOBAL event_scheduler=ON to enable it. SET GLOBAL event_scheduler= ON; SHOW FULL PROCESSLIST; Id User Host db Command Time State Info Progress 4 root localhost test Query 0 starting SHOW FULL PROCESSLIST 0.000 5 event_scheduler localhost NULL Daemon 1 Waiting for next activation NULL 0.000 6 root localhost test Connect 1 User sleep INSERT INTO t1 VALUES(SLEEP(3)) 0.000 SET GLOBAL event_scheduler= OFF; DROP EVENT ev1; SHOW FULL PROCESSLIST; Id User Host db Command Time State Info Progress 4 root localhost test Query 0 starting SHOW FULL PROCESSLIST 0.000 6 root localhost test Connect 1 User sleep INSERT INTO t1 VALUES(SLEEP(3)) 0.000 SHOW FULL PROCESSLIST; Id User Host db Command Time State Info Progress 4 root localhost test Query 0 starting SHOW FULL PROCESSLIST 0.000 6 root localhost test Connect 2 User sleep INSERT INTO t1 VALUES(SLEEP(3)) 0.000 DROP TABLE t1; ----------------------------------------------------------------------- - Kristian.