Job uniqueness for ActiveJob

The gem allows to protect job uniqueness with next strategies:

Strategy	The job is locked	The job is unlocked
until_executing	when pushed to the queue	when processing starts
until_executed	when pushed to the queue	when the job is processed successfully
until_expired	when pushed to the queue	when the lock is expired
until_and_while_executing	when pushed to the queue	when processing starts a runtime lock is acquired to prevent simultaneous jobs has extra options: runtime_lock_ttl, on_runtime_conflict
while_executing	when processing starts	when the job is processed with any result including an error

Inspired by SidekiqUniqueJobs, uses Redlock under the hood.

Installation

Add the activejob-uniqueness gem to your Gemfile.

gem 'activejob-uniqueness'

If you want jobs unlocking for Sidekiq Web UI, require the patch explicitly. Queues cleanup becomes slower!

gem 'activejob-uniqueness', require: 'active_job/uniqueness/sidekiq_patch'

And run bundle install command.

Configuration

ActiveJob::Uniqueness is ready to work without any configuration. It will use REDIS_URL to connect to Redis instance. To override the defaults, create an initializer config/initializers/active_job_uniqueness.rb using the following command:

rails generate active_job:uniqueness:install

Usage

Make the job to be unique

class MyJob < ActiveJob::Base
  # new jobs with the same args will raise error until existing one is executed
  unique :until_executed

  def perform(args)
    # work
  end
end

Tune uniqueness settings per job

class MyJob < ActiveJob::Base
  # new jobs with the same args will be logged within 3 hours or until existing one is being executing
  unique :until_executing, lock_ttl: 3.hours, on_conflict: :log

  def perform(args)
    # work
  end
end

You can set defaults globally with the configuration

Control lock conflicts

class MyJob < ActiveJob::Base
  # Proc gets the job instance including its arguments
  unique :until_executing, on_conflict: ->(job) { job.logger.info "Oops: #{job.arguments}" }

  def perform(args)
    # work
  end
end

Control lock key arguments

class MyJob < ActiveJob::Base
  unique :until_executed

  def perform(foo, bar, baz)
    # work
  end

  def lock_key_arguments
    arguments.first(2) # baz is ignored
  end
end

Control the lock key

class MyJob < ActiveJob::Base
  unique :until_executed

  def perform(foo, bar, baz)
    # work
  end

  def lock_key
    'qux' # completely custom lock key
  end

  def runtime_lock_key
    'quux' # completely custom runtime lock key for :until_and_while_executing
  end
end

Unlock jobs manually

The selected strategy automatically unlocks jobs, but in some cases (e.g. the queue is purged) it is handy to unlock jobs manually.

# Remove the lock for particular arguments:
MyJob.unlock!(foo: 'bar')
# or
ActiveJob::Uniqueness.unlock!(job_class_name: 'MyJob', arguments: [{foo: 'bar'}])

# Remove all locks of MyJob
MyJob.unlock!
# or
ActiveJob::Uniqueness.unlock!(job_class_name: 'MyJob')

# Remove all locks
ActiveJob::Uniqueness.unlock!

Test mode

Most probably you don't want jobs to be locked in tests. Add this line to your test suite (rails_helper.rb):

ActiveJob::Uniqueness.test_mode!

Logging

ActiveJob::Uniqueness instruments ActiveSupport::Notifications with next events:

• lock.active_job_uniqueness
• runtime_lock.active_job_uniqueness
• unlock.active_job_uniqueness
• runtime_unlock.active_job_uniqueness
• conflict.active_job_uniqueness
• runtime_conflict.active_job_uniqueness

And then writes to ActiveJob::Base.logger.

ActiveJob prior to version 6.1 will always log Enqueued MyJob (Job ID) ... even if the callback chain is halted. Details

Testing

Run redis server (in separate console):

docker run --rm -p 6379:6379 redis

Run tests with:

bundle
rake

Sidekiq API support

ActiveJob::Uniqueness supports Sidekiq API to unset job locks on queues cleanup (e.g. via Sidekiq Web UI). Starting Sidekiq 5.1 job death also triggers locks cleanup. Take into account that big queues cleanup becomes much slower because each job is being unlocked individually. In order to activate Sidekiq API patch require it explicitly in your Gemfile:

gem 'activejob-uniqueness', require: 'active_job/uniqueness/sidekiq_patch'

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/veeqo/activejob-uniqueness.

License

The gem is available as open source under the terms of the MIT License.

About Veeqo

At Veeqo, our team of Engineers is on a mission to create a world-class Inventory and Shipping platform, built to the highest standards in best coding practices. We are a growing team, looking for other passionate developers to join us on our journey. If you're looking for a career working for one of the most exciting tech companies in ecommerce, we want to hear from you.

Veeqo developers blog