Edgar Gonzalez

Resque :: How to clear old workers from Redis

In a Rails 3 application we’re using resque for background jobs. Because we’re running on heroku, with new deploys sometimes appears “phantom” resque workers in resque-web, this “phantom” workers are old workers that running on a previous EC2 instance that currently is terminated, so the phantom workers really don’t exist but the keys are still in Redis.

The way I clean this phantom workers is:

File: ./lib/resque_ext.rb

module ResqueExt
  #
  # ResqueExt.unregister_workers_for_host("ec210-250-192-51")
  #
  def self.unregister_workers_for_host(host)
    Resque.workers.select{|worker| worker.id.split(':').first==host}.each(&:unregister_worker)
  end
end

BTW the ./config/application.rb file includes the ./lib folder to be autoloadable:

config.autoload_paths += %W(#{config.root}/lib)

Based on this gist