Avoid SQL contention in events

events_safe.sql

DELIMITER //
CREATE EVENT testlock_event ON SCHEDULE EVERY 2 SECOND DO
BEGIN
 DECLARE CONTINUE HANDLER FOR SQLEXCEPTION
 BEGIN
   DO RELEASE_LOCK('testlock_event');
 END;
 IF GET_LOCK('testlock_event', 0) THEN
   -- add some business logic here, for example:
   -- insert into test.testlock_event values(NULL, NOW());
  END IF;
  DO RELEASE_LOCK('testlock_event');
END;
//
DELIMITER ;