README.adoc

Sidekiq::Throttled

Note	This is the 1.x development branch. For the 0.x stable branch, please see: 0-x-stable

Concurrency and threshold throttling for Sidekiq.

Installation

Add this line to your application’s Gemfile:

gem "sidekiq-throttled"

And then execute:

$ bundle

Or install it yourself as:

$ gem install sidekiq-throttled

Usage

Add somewhere in your app’s bootstrap (e.g. config/initializers/sidekiq.rb if you are using Rails):

require "sidekiq/throttled"
Sidekiq::Throttled.setup!

Load order can be an issue if you are using other Sidekiq plugins and/or middleware. To prevent any problems, add the .setup! call to the bottom of your init file.

Once you’ve done that you can include Sidekiq::Throttled::Job to your job classes and configure throttling:

class MyJob
  include Sidekiq::Job
  include Sidekiq::Throttled::Job

  sidekiq_options :queue => :my_queue

  sidekiq_throttle(
    # Allow maximum 10 concurrent jobs of this class at a time.
    :concurrency => { :limit => 10 },
    # Allow maximum 1K jobs being processed within one hour window.
    :threshold => { :limit => 1_000, :period => 1.hour }
  )

  def perform
    # ...
  end
end

Tip	Sidekiq::Throttled::Job is aliased as Sidekiq::Throttled::Worker, thus if you’re using Sidekiq::Worker naming convention, you can use the alias for consistency:

class MyWorker
  include Sidekiq::Worker
  include Sidekiq::Throttled::Worker

  # ...
end

Observer

You can specify an observer that will be called on throttling. To do so pass an :observer option with callable object:

class MyJob
  include Sidekiq::Job
  include Sidekiq::Throttled::Job

  MY_OBSERVER = lambda do |strategy, *args|
    # do something
  end

  sidekiq_options :queue => :my_queue

  sidekiq_throttle(
    :concurrency => { :limit => 10 },
    :threshold   => { :limit => 100, :period => 1.hour },
    :observer    => MY_OBSERVER
  )

  def perform(*args)
    # ...
  end
end

Observer will receive strategy, *args arguments, where strategy is a Symbol :concurrency or :threshold, and *args are the arguments that were passed to the job.

Dynamic throttling

You can throttle jobs dynamically with :key_suffix option:

class MyJob
  include Sidekiq::Job
  include Sidekiq::Throttled::Job

  sidekiq_options :queue => :my_queue

  sidekiq_throttle(
    # Allow maximum 10 concurrent jobs per user at a time.
    :concurrency => { :limit => 10, :key_suffix => -> (user_id) { user_id } }
  )

  def perform(user_id)
    # ...
  end
end

You can also supply dynamic values for limits and periods by supplying a proc for these values. The proc will be evaluated at the time the job is fetched and will receive the same arguments that are passed to the job.

class MyJob
  include Sidekiq::Job
  include Sidekiq::Throttled::Job

  sidekiq_options :queue => :my_queue

  sidekiq_throttle(
    # Allow maximum 1000 concurrent jobs of this class at a time for VIPs and 10 for all other users.
    :concurrency => {
      :limit      => ->(user_id) { User.vip?(user_id) ? 1_000 : 10 },
      :key_suffix => ->(user_id) { User.vip?(user_id) ? "vip" : "std" }
    },
    # Allow 1000 jobs/hour to be processed for VIPs and 10/day for all others
    :threshold   => {
      :limit      => ->(user_id) { User.vip?(user_id) ? 1_000 : 10 },
      :period     => ->(user_id) { User.vip?(user_id) ? 1.hour : 1.day },
      :key_suffix => ->(user_id) { User.vip?(user_id) ? "vip" : "std" }
    }
  )

  def perform(user_id)
    # ...
  end
end

You also can use several different keys to throttle one worker.

class MyJob
  include Sidekiq::Job
  include Sidekiq::Throttled::Job

  sidekiq_options :queue => :my_queue

  sidekiq_throttle(
    # Allow maximum 10 concurrent jobs per project at a time and maximum 2 jobs per user
    :concurrency => [
      { :limit => 10, :key_suffix => -> (project_id, user_id) { project_id } },
      { :limit => 2, :key_suffix => -> (project_id, user_id) { user_id } }
    ]
    # For :threshold it works the same
  )

  def perform(project_id, user_id)
    # ...
  end
end

Important

Don’t forget to specify :key_suffix and make it return different values if you are using dynamic limit/period options. Otherwise, you risk getting into some trouble.

Concurrency throttling fine-tuning

Concurrency throttling is based on distributed locks. Those locks have default time to live (TTL) set to 15 minutes. If your job takes more than 15 minutes to finish, lock will be released and you might end up with more jobs running concurrently than you expect.

This is done to avoid deadlocks - when by any reason (e.g. Sidekiq process was OOM-killed) cleanup middleware wasn’t executed and locks were not released.

If your job takes more than 15 minutes to complete, you can tune concurrency lock TTL to fit your needs:

# Set concurrency strategy lock TTL to 1 hour.
sidekiq_throttle(:concurrency => { :limit => 20, :ttl => 1.hour.to_i })

Supported Ruby Versions

This library aims to support and is tested against the following Ruby versions:

• Ruby 2.7.x

• Ruby 3.0.x

• Ruby 3.1.x

If something doesn’t work on one of these versions, it’s a bug.

This library may inadvertently work (or seem to work) on other Ruby versions, however support will only be provided for the versions listed above.

If you would like this library to support another Ruby version or implementation, you may volunteer to be a maintainer. Being a maintainer entails making sure all tests run and pass on that implementation. When something breaks on your implementation, you will be responsible for providing patches in a timely fashion. If critical issues for a particular implementation exist at the time of a major release, support for that Ruby version may be dropped.

Supported Sidekiq Versions

This library aims to support and work with following Sidekiq versions:

• Sidekiq 6.4.x

• Sidekiq 6.5.x

Contributing

• Fork sidekiq-throttled on GitHub

• Make your changes

• Ensure all tests pass (bundle exec rake)

• Send a pull request

• If we like them we’ll merge them

• If we’ve accepted a patch, feel free to ask for commit access!

Development

bundle update
bundle exec appraisal install   # install dependencies for all gemfiles
bundle exec appraisal update    # update dependencies for all gemfiles
bundle exec appraisal rspec     # run rspec against each gemfile
bundle exec rubocop             # run static code analysis

Don’t forget to run appraisal update after any changes to Gemfile.