Load Balancing Fundamentals
Before we dive into the specifics of tools like HAProxy, Nginx, or cloud-native solutions, we need to build a general overview of what load balancing actually is. At its simplest, load balancing answers a single question: When a client wants to talk to "the service," which specific server should actually handle that request? Why Do We Need It? You need load balancing the moment a single server can no longer (or should no longer) handle your traffic alone. It provides three core pillars for your infrastructure: Scalability: The ability to spread traffic across many servers instead of one. Availability: If one server fails, the load balancer shifts traffic to the healthy servers. Flexibility: You can add, remove, or replace backend servers without the client ever noticing. Everything else - algorithms, health checks, SSL termination, routing rules - exists in service of that one core job. The Four Layers of Traffic Management It helps to think of traffic control as happening ac...