delayed_job is a process based asynchronous task processing gem which can be ran at background. It will fork the specified number of processes to execute the tasks asynchronously. The task status is usually stored in the database so that it can be easily integrated into a Rails application where asynchronous job execution is desired.Normally when a job fails to execute or error occurs, it would save the error into the database with the column last_error. Ideally all these will be handled by the delayed_job gem itself, we no need to worry about anything. However, in some extreme cases, we ...