Active Job Basics ================= This guide provides you with all you need to get started in creating, enqueueing and executing background jobs. After reading this guide, you will know: * How to create jobs. * How to enqueue jobs. * How to run jobs in the background. * How to send emails from your application async. -------------------------------------------------------------------------------- Introduction ------------ Active Job is a framework for declaring jobs and making them run on a variety of queueing backends. These jobs can be everything from regularly scheduled clean-ups, billing charges, or mailings. Anything that can be chopped up into small units of work and run in parallel, really. The Purpose of the Active Job ----------------------------- The main point is to ensure that all Rails apps will have a job infrastructure in place, even if it's in the form of an "immediate runner". We can then have framework features and other gems build on top of that, without having to worry about API differences between Delayed Job and Resque. Picking your queuing backend becomes more of an operational concern, then. And you'll be able to switch between them without having to rewrite your jobs. Creating a Job -------------- This section will provide a step-by-step guide to creating a job and enqueue it. ### Create the Job Active Job provides a Rails generator to create jobs. The following will create a job in app/jobs: ```bash $ bin/rails generate job guests_cleanup create app/jobs/guests_cleanup_job.rb ``` You can also create a job that will run on a specific queue: ```bash $ bin/rails generate job guests_cleanup --queue urgent create app/jobs/guests_cleanup_job.rb ``` As you can see, you can generate jobs just like you use other generators with Rails. If you don't want to use a generator, you could create your own file inside of app/jobs, just make sure that it inherits from `ActiveJob::Base`. Here's how a job looks like: ```ruby class GuestsCleanupJob < ActiveJob::Base queue_as :default def perform # Do something later end end ``` ### Enqueue the Job Enqueue a job like so: ```ruby MyJob.enqueue record # Enqueue a job to be performed as soon the queueing system is free. ``` ```ruby MyJob.enqueue_at Date.tomorrow.noon, record # Enqueue a job to be performed tomorrow at noon. ``` ```ruby MyJob.enqueue_in 1.week, record # Enqueue a job to be performed 1 week from now. ``` That's it! Job Execution ------------- If not adapter is set, the job is immediately executed. ### Backends Active Job has adapters for the following queueing backends: * [Backburner](https://github.com/nesquena/backburner) * [Delayed Job](https://github.com/collectiveidea/delayed_job) * [Qu](https://github.com/bkeepers/qu) * [Que](https://github.com/chanks/que) * [QueueClassic](https://github.com/ryandotsmith/queue_classic) * [Resque 1.x](https://github.com/resque/resque) * [Sidekiq](https://github.com/mperham/sidekiq) * [Sneakers](https://github.com/jondot/sneakers) * [Sucker Punch](https://github.com/brandonhilkert/sucker_punch) #### Backends Features
Async | Queues | Delayed | Priorities | Timeout | Retries | |
Backburner | Yes | Yes | Yes | Yes | Job | Global |
Delayed Job | Yes | Yes | Yes | Job | Global | Global |
Que | Yes | Yes | Yes | Job | No | Job |
Queue Classic | Yes | Yes | Gem | No | No | No |
Resque | Yes | Yes | Gem | Queue | Global | ? |
Sidekiq | Yes | Yes | Yes | Queue | No | Job |
Sneakers | Yes | Yes | No | Queue | Queue | No |
Sucker Punch | Yes | Yes | Yes | No | No | No |
Active Job | Yes | Yes | WIP | No | No | No |
Active Job Inline | No | Yes | N/A | N/A | N/A | N/A |