Journey to a Multi-Connection Server
Overview
Implementing a server application that can handle multiple client requests simultaneously is now very easy. Just using Spring MVC alone can get you there in no time. However, as an engineer, I am curious about the underlying principles. In this article, we will embark on a journey to reflect on the considerations that were made to implement a multi-connection server by questioning the things that may seem obvious.
You can check the example code on GitHub.
Socket
The first destination is 'Socket'. From a network programming perspective, a socket is a communication endpoint used like a file to exchange data over a network. The description 'used like a file' is important because it is accessed through a file descriptor (fd) and supports I/O operations similar to files.
While sockets can be identified using one's IP, port, and the other party's IP and port, using fd is preferred because sockets have no information until a connection is accepted, and more data is needed than just a simple integer like fd.
To implement a server application using sockets, you need to go through the following steps: