Redlock provides a ruby distributed lock using redis.

Distributed locks are a very useful primitive in many environments where
different processes require to operate with shared resources in a mutually
exclusive way.

There are a number of libraries and blog posts describing how to implement a DLM
(Distributed Lock Manager) with Redis, but every library uses a different
approach, and many use a simple approach with lower guarantees compared to what
can be achieved with slightly more complex designs.

This is an implementation of a proposed distributed lock algorithm with Redis.
It started as a fork from antirez implementation.