WatcherOnTheWall

WatcherOnTheWall aims to provide a single instance mutual exclusion lock for running ruby scripts

Installation

Add this line to your application's Gemfile:

gem 'watcher_on_the_wall'

And then execute:

$ bundle

Or install it yourself as:

$ gem install watcher_on_the_wall

Usage

WatcherOnTheWall will automatically hook onto your existing Redis instance, so in order to use that you'll just need to use the following method

    redis = Redis.new # Or whatever

    redis.watcher_on_the_wall(unique_key: "my_script_is_running_now", auto_expire_in_seconds: 300) do
      # I am a script that does things but i can't be started again until i'm done.
    end

Options

• unique_key - this will be used as a Redis key to and will be checked and locked accordingly by the running scripts. defaults to a random 60 chars long string.
• auto_expire_in_seconds - specifiy the number of seconds to auto-expire the mutex key to ensure it is not helf forever if something happens, if you specify false no expiry interval will be set (not recommended). defaults to 300 seconds (5 minutes).

The lock and key will be released and deleted once the run is over.

Exceptions

If you will try to run a script that uses the same unique_key while one is still running, WatcherOnTheWall will raise an WatcherOnTheWall::Exceptions::AlreadyRunning exception.

Contributing

1. Fork it ( http://github.com//watcher_on_the_wall/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request