Listen to 'error' event.
This event is triggered when an exception is thrown.
Listen to 'failed' event.
This event is triggered when a job has thrown an exception.
Listen to 'ioredis:close' event.
This event is triggered when ioredis is closed.
Listen to 'stalled' event.
This event is triggered when a job gets stalled.
Listen to 'error' event.
This event is triggered when an exception is thrown.