In the post Use background jobs with single process, I have mentioned to the ActiveJob at the end of post. In this post, I will introduce and explain more detailed about this new feature of Rails 4.2 as well as an overview of popular background job gems. What is

As we already know (almost?) that we should use background jobs to process long tasks (or even not so long task but can be processed later) to improve performance and user experience, a very common example is sending email. We often use some gems like: Delayed Job, Sidekiq, Resque... So