Need for External Message Brokers

Welcome! Modern web applications often need to communicate in real-time. Think about chat apps, live dashboards, or online games.

As your app grows, more users will connect simultaneously. This lesson explores a key challenge: how do you keep your real-time system fast and reliable when handling thousands or millions of users?

When you first set up a Spring WebSocket application, you typically use an in-memory message broker (like Spring's SimpleBrokerMessageHandler).

An in-memory broker lives directly within your application's process. It handles message routing and subscriptions for all clients connected to that specific application instance.