Backend services
If you are using Go, it is likely that you have written or will write a backend service of some sort. Service development comes with a unique set of challenges. First, the concurrency aspect of request handling is usually hidden under a service framework, which causes unintentional memory sharing and data races. Second, not all clients of the service have good intentions (attacks) or are free of bugs. In this section, we will look at some basic constructs using HTTP and web socket services. But before those, knowing a bit about TCP networking helps because many higher-level protocols like HTTP and web sockets are based on TCP. Next, we will construct a simple TCP server that handles requests concurrently and shuts down gracefully. For this, we need a listener, a request handler, and a wait group:
type TCPServer struct {
Listener net.Listener
HandlerFunc func(context.Context,net.Conn...
