Chapter 11. The Manager Component

HTTP is intrinsically a stateless protocol. Each incoming request is a separate independent event, and once the server has responded to a given request, it does not hold any information about the requesting client.

This statelessness was well suited for the original intent of the Internet as a global file sharing mechanism, where a client may connect to a server and request a particular file. The client would then wait on that connection for the server to respond with the contents of the specified file. Once the file had been transferred, the connection would be closed and the server would retain no active memory of the client that it had just serviced.

This resulted in an architecture that was highly performant and scalable, as a server incurred minimal overhead while performing its core task of accessing and transmitting a file.

The challenge, however, is that any non-trivial web application does much more than just retrieve a file or resource. In applications...