Resque Unique

This is a modified version of resque-lock. This version uses the algorithm mentioned in the Redis SETNX documentation to avoid deadlocks. This version should also clean up the locks after the worker is finished performing, regardless of the outcome.

A Resque plugin. Requires Resque 1.7.0.

If you want only one instance of your job queued at a time, extend it with this module.

For example:

require 'resque/plugins/unique'

class UpdateNetworkGraph
  extend Resque::Plugins::Unique

  def self.perform(repo_id)
    heavy_lifting
  end
end

While this job is queued or running, no other UpdateNetworkGraph jobs with the same arguments will be placed on the queue.

If you want to define the key yourself you can override the lock class method in your subclass, e.g.

class UpdateNetworkGraph
  extend Resque::Plugins::Unique

  Run only one at a time, regardless of repo_id.
  def self.lock(repo_id)
    "network-graph"
  end

  def self.perform(repo_id)
    heavy_lifting
  end
end

The above modification will ensure only one job of class UpdateNetworkGraph is queued at a time, regardless of the repo_id. Normally a job is locked using a combination of its class name and arguments.