What aynchronous Ruby server to use?

We're starting development of the new game project using Ruby. We decided to use one of the asynchronous Rub开发者_JAVA百科y servers, but we cannot decide which one to choose. Options are:

• Goliath
• Cramp + thin/rainbows
• rack-fiber_pool + rack + thin/rainbows
• eventmachine_httpserver

All of them seem to be working with HTTP requests. Cramp also supports Websockets and Server-Side events from the box.

Do you know any pros & cons of these servers?

I've used eventmachine_httpserver to expose a RESTful API in an EventMachine-based IRC bot and would definitely not recommend it for anything serious. It seems more like a minimal proof-of-concept than a serious web server, perhaps best illustrated by the parse_headers hack I had to use.

You may also want to look pub/sub services like nats.