This gem allows you to lock specific chunks of code based on a shared key. It's a Mutex, but locks beyond a single machine by utilizing Redis's SETNX. This code was originally extracted from Discourse into Uncharted Scheduler and later extracted from there into it's own repository.

Add this line to your application's Gemfile:

gem 'distributed-mutex'

And then execute:

$ bundle

Or install it yourself as:

$ gem install distributed-mutex

You simply need to wrap your code in a block and give it a key.

require 'distributed-mutex'

DistributedMutex.new("custom-key").syncronize do
  puts "Custom Code"
end

After checking out the repo, run bin/setup to install dependencies. Then, run rake rspec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/uncharted-code/distributed-mutex.

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