The gem allows to protect job uniqueness with next strategies:

Inspired by SidekiqUniqueJobs, uses Redlock under the hood.

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.

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

This gem relies on redlock for it's Redis connection, that means it will not inherit global configuration of Sidekiq. To configure the connection, you can use config.redlock_servers, for example to disable SSL verification for Redis/Key-Value cloud providers:

ActiveJob::Uniqueness.configure do |config|
  config.redlock_servers = [
    RedisClient.new(
      url: ENV['REDIS_URL'],
      ssl_params: { verify_mode: OpenSSL::SSL::VERIFY_NONE }
    )
  ]
end

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

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

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

class MyJob < ActiveJob::Base
  # Proc gets the job instance including its arguments, and as keyword arguments the resource(lock key) `resource` and the original error `error`
  unique :until_executing, on_redis_connection_error: ->(job, resource: _, error: _) { job.logger.info "Oops: #{job.arguments}" }

  def perform(args)
    # work
  end
end

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

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

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!

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!

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

Run redis server (in separate console):

docker run --rm -p 6379:6379 redis

Run tests with:

bundle
rake

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'

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

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

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