Delayed::Cron::Job

Delayed::Cron::Job is an extension to Delayed::Job that allows you to set cron expressions for your jobs to run repeatedly.

Installation

Add this line to your application's Gemfile:

gem 'delayed_cron_job'

And then execute:

$ bundle

If you are using delayed_job_active_record, generate a migration (after the original delayed job migration) to add the cron column to the delayed_jobs table:

$ rails generate delayed_job:cron
$ rake db:migrate

There are no additional steps for delayed_job_mongoid.

Usage

When enqueuing a job, simply pass the cron option, e.g.:

Delayed::Job.enqueue(MyRepeatedJob.new, cron: '15 */6 * * 1-5')

Or, when using Active Job:

MyJob.set(cron: '*/5 * * * *').perform_later

Any crontab compatible cron expressions are supported (see man 5 crontab). The credits for the Cronline class used go to rufus-scheduler.

 Details

The initial run_at value is computed during the #enqueue method call. If you create Delayed::Job database entries directly, make sure to set run_at accordingly.

You may use the id of the Delayed::Job as returned by the #enqueue method to reference and/or remove the scheduled job in the future.

The subsequent run of a job is only scheduled after the current run has terminated. If a single run takes longer than the given execution interval, some runs may be skipped. E.g., if a run takes five minutes, but the job is scheduled to be executed every second minute, it will actually only execute every sixth minute: With a cron of */2 * * * *, if the current run starts at :00 and finishes at :05, then the next scheduled execution time is at :06, and so on.

If you do not want longer running jobs to skip executions, simply create a lightweight master job that enqueues the actual workload as separate jobs. Of course you have to make sure to start enough workers to handle all these jobs.

Contributing

  1. Fork it ( https://github.com/codez/delayed_cron_job/fork )
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Add some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create a new Pull Request