It's not "the ROR model". Rails is just an actor in the Rack space; how the framework handles feeds requests to Rails is entirely up the Rack adapter.
Rails itself is thread-safe and can handle requests concurrently with multiple threads; it can also run in a multi-process configuration.
The setup described in the article focuses on Thin, a web server that is primarily single-threaded. These days, many people use Unicorn, which uses a forking model to serve requests from concurrent processes.
It's not "the ROR model". Rails is just an actor in the Rack space; how the framework handles feeds requests to Rails is entirely up the Rack adapter.
Rails itself is thread-safe and can handle requests concurrently with multiple threads; it can also run in a multi-process configuration.
The setup described in the article focuses on Thin, a web server that is primarily single-threaded. These days, many people use Unicorn, which uses a forking model to serve requests from concurrent processes.