Rails hits the Metal
David Heinemeier Hansson, creator of Ruby on Rails, has announced Rails Metal, a wrapper around Rack for developers who need to have a very fast response service integrated with Rails. An example of a service which would need this capability would be a poller service, where clients may be checking for updates regularly and the CPU time taken for those requests to travel through the Rails router and controller would be too much. Rails Metal lets Rails developers create these services using Rack to handle the requests and handing them to a simple Ruby service implementation.
In an update to the announcement, Hansson pointed to another blog entry which gave more examples and benchmarked the new service getting time per request down from 2.448ms to 0.866ms.