So, what is Gearman?

Gearman is a network-based job-queuing system that was initially developed by Danga Interactive in order to process large volumes of jobs. Its primary design goals were low-latency remote function execution, being able to run code remotely and in parallel, load balancing of job distribution, and supporting writing components in multiple languages.

Although originally written in Perl it is comprised of, at its core, a network protocol that is designed to allow the various components to communicate the lifecycle of a unit of work. Because of this design, there are both servers and client libraries written in multiple languages including Ruby, Perl, PHP, Python, C, C++, and Java.

What this translates into is the ability to design and develop the various components of your architecture in whatever language makes the most sense and have those components communicate easily with one another.

Gearman goes one step further than simply defining a message bus; it formalizes its architecture to focus on units of work. This means that everything in a system using Gearman operates in terms of submitting or working on jobs. To follow this paradigm, Gearman has three main actors: clients who request that work be completed by somebody, the managers (servers) that are responsible for accepting jobs from clients, and then handing those jobs out to workers that ultimately complete the tasks.