Overview

Introduction

It’s important for our applications to have the ability to communicate with the server asynchronously and in real-time. Moreover, we probably realize that the standard request-response model of communication isn’t fully suitable for modern apps. Sometimes, our client application (whether it’s a web page, a mobile app, or a service on an IoT device) needs to be able to receive a real-time update from the server that was actually triggered by an event on the server and not by a client request.

We see this functionality everywhere. When we use a messenger app, we expect to receive a message as soon as someone has sent us one. When we control our IoT devices, we expect them to respond to our commands as soon as we trigger them.