Alert syncer calls am_db_remove_expired_mediatypes() every 1 hour for removing mediatype from cache. The removing rule is 'not to be used over 1 day'.
But, its process calls it just after booting. It is not needed and additionally calling it for 1 day after booting. So, I posted the patch not to call its function for 1day + 1 hour after Zabbix server booted.

See ZBX-17570