Handling multiple WebSocket connections and broadcasting messages
As we said in the introduction to this chapter, a typical use case for WebSockets is to implement real-time communication across multiple clients, such as a chat application. In this configuration, several clients have an open WebSocket tunnel with the server. Thus, the role of the server is to manage all the client connections and broadcast messages to all of them: when a user sends a message, the server has to send it to all other clients in their WebSockets. We show you a schema of this principle here:
Figure 8.4 – Multiple clients connected through a WebSocket to a server
A first approach could be simply to keep a list of all WebSocket connections and iterate through them to broadcast messages. This would work but would quickly become problematic in a production environment. Indeed, most of the time, server processes run multiple workers when deployed. This means that instead...
