Erlang and Ruby Roundup: Vertebra, Scaling with Fuzed, Github
EngineYard's Vertebra is based on a combination of Ruby and Erlang. From our previous coverage:
The security/discovery mechanism, the state machine workflow system and the distributed key-value storage system are all written in Erlang. The agent framework for writing agents is all ruby though and the actual functionality of the agents is ruby.The system is also built around the Erlang-based ejabberd which implements messaging using XMPP. Another messaging system written in Erlang is RabbitMQ, which implements AMQP, an Internet Protocol for Business Messaging
The search engine Powerset (Microsoft recently acquired Powerset) is built on a host of technologies, including Erlang and Ruby. A part of this infrastructure is now available at Github under the name Fuzed. From the project's Readme:
Fuzed is an Erlang-based clustering system designed to let several single-threaded processes (which may or may not be reliable) form into a pool which can serve requests to remote hosts. These resources need not be homogeneous, Fuzed breaks them up into homogeneous pools internally and serves out requests without "crossing the streams" of different software/versions of software.Fuzed makes use of Erlectricity (RubyForge project), a library that connects Ruby and Erlang, similar to the JInterface library which connects Java and Erlang. These libraries are built on Erlang's ports and messaging system. For a quick overview, read Scott Fleckenstein's introduction to Erlectricity. Scott Chacon wrote up his experience in using Fuzed on Amazon EC2.
This is a release of Powerset's internal clustering software which has been adapted for use with Rails, but see the generic_json_responder to see exactly how it is used internally.
Finally, Tom Preston-Werner mentioned on the github blog he's working on egitd:
Over the past several weeks I’ve been working on a secret Erlang project that will allow us to grow GitHub in new and novel ways. The project is called egitd and is a replacement for the stock git-daemon that ships with git.