SidekiqScheduler

Description

sidekiq-scheduler is an extension to Sidekiq that adds support for running scheduled.

Scheduled jobs are like cron jobs, recurring on a regular basis.

Documentation

This README covers what most people need to know. If you're looking for details on individual methods, you might want to try the rdoc.

Installation

# Add this to your Gemfile:
gem 'sidekiq-scheduler', '=> 0.6'

# Starting the scheduler
bundle exec sidekiq-scheduler

The scheduler will perform identically to a normal sidekiq worker with an additional scheduler thread being run - in the default configuration this will result in 25 worker threads being available on the scheduler node but all normal configuration options apply.

NOTE: Since it's currently not possible to hook into the default option parsing provided by sidekiq you will need to use a configuration file to override the scheduler options. Available options are:

:schedule: <the schedule to be run>
:dynamic: <if true the schedule can we modified in runtime>

The scheduling thread will sleep this many seconds between looking for jobs that need moving to the worker queue. The default is 5 seconds which should be fast enough for almost all uses.

NOTE: You DO NOT want to run more than one instance of the scheduler. Doing so will result in the same job being queued multiple times. You only need one instance of the scheduler running per application, regardless of number of servers.

NOTE: If the scheduler thread goes down for whatever reason, the delayed items that should have fired during the outage will fire once the scheduler is started back up again (even if it is on a new machine).

Scheduled Jobs (Recurring Jobs)

Scheduled (or recurring) jobs are logically no different than a standard cron job. They are jobs that run based on a fixed schedule which is set at startup.

The schedule is a list of Sidekiq worker classes with arguments and a schedule frequency (in crontab syntax). The schedule is just a hash, but is most likely stored in a YAML like so:

CancelAbandonedOrders:
  cron: "*/5 * * * *"

queue_documents_for_indexing:
  cron: "0 0 * * *"
  # you can use rufus-scheduler "every" syntax in place of cron if you prefer
  # every: 1hr
  # By default the job name (hash key) will be taken as worker class name.
  # If you want to have a different job name and class name, provide the 'class' option
  class: QueueDocuments
  queue: high
  args:
  description: "This job queues all content for indexing in solr"

clear_leaderboards_contributors:
  cron: "30 6 * * 1"
  class: ClearLeaderboards
  queue: low
  args: contributors
  description: "This job resets the weekly leaderboard for contributions"

You can provide options to "every" or "cron" via Array:

clear_leaderboards_moderator:
  every: ["30s", :first_in => '120s']
  class: CheckDaemon
  queue: daemons
  description: "This job will check Daemon every 30 seconds after 120 seconds after start"

NOTE: Six parameter cron's are also supported (as they supported by rufus-scheduler which powers the sidekiq-scheduler process). This allows you to schedule jobs per second (ie: "30 * * * * *" would fire a job every 30 seconds past the minute).

A big shout out to rufus-scheduler for handling the heavy lifting of the actual scheduling engine.

Loading the schedule

Let's assume your scheduled jobs are defined in a file called "config/scheduler.yml" under your Rails project, you could create a Rails initializer called "config/initializer/scheduler.rb" which would load the job definitions:

require 'sidekiq/scheduler'
Sidekiq.schedule = YAML.load_file(File.expand_path("../../../config/scheduler.yml",__FILE__))

If you were running a non Rails project you should add code to load the workers classes before loading the schedule.

require 'sidekiq/scheduler'
Dir[File.expand_path('../lib/workers/*.rb',__FILE__)].each do |file| load file; end
Sidekiq.schedule = YAML.load_file(File.expand_path("../../../config/scheduler.yml",__FILE__))

Time zones

Note that if you use the cron syntax, this will be interpreted as in the server time zone rather than the config.time_zone specified in Rails.

You can explicitly specify the time zone that rufus-scheduler will use:

cron: "30 6 * * 1 Europe/Stockholm"

Also note that config.time_zone in Rails allows for a shorthand (e.g. "Stockholm") that rufus-scheduler does not accept. If you write code to set the scheduler time zone from the config.time_zone value, make sure it's the right format, e.g. with:

ActiveSupport::TimeZone.find_tzinfo(Rails.configuration.time_zone).name

A future version of sidekiq-scheduler may do this for you.

Using with Testing

Sidekiq uses a jobs array on workers for testing, which is supported by sidekiq-scheduler when you require the test code:

require 'sidekiq/testing'
require 'sidekiq-scheduler/testing'

MyWorker.perform_in 5, 'arg1'
puts MyWorker.jobs.inspect

Note on Patches / Pull Requests

Fork the project.
Make your feature addition or bug fix.
Add tests for it. This is important so I don't break it in a future version unintentionally.
Commit, do not mess with rakefile, version, or history. (if you want to have your own version, that is fine but bump version in a commit by itself I can ignore when I pull)
Send me a pull request. Bonus points for topic branches.

Credits

This work is a partial port of resque-scheduler by Ben VandenBos.
Modified to work with the Sidekiq queueing library by Morton Jonuschat. Scheduling of recurring jobs has been added to v0.4.0, thanks to Adrian Gomez.

Maintainers

License

MIT License