These states occur for the Event Scheduler thread, threads that are created to execute scheduled events, or threads that terminate the scheduler. 

• Clearing 

The scheduler thread or a thread that was executing an event is terminating and is about to end. 

• Initialized 

The scheduler thread or a thread that executes an event has been initialized. 

• Waiting for next activation 

The scheduler has a nonempty event queue but the next activation is in the future. 

• Waiting for scheduler to stop 

The thread issued SET GLOBAL event_scheduler=OFF  and is waiting for the scheduler to stop. 

• Waiting on empty queue 

The scheduler’s event queue is empty and it is sleeping. 

