What is Load Balancing?

How Load Balancing Works

When a single server cannot handle the flow of requests, traffic is distributed across multiple servers through a load balancer. It accepts all incoming requests and directs each one to an available server using a specific algorithm. If one server goes down, the load balancer automatically redirects traffic to the remaining servers, ensuring continuous operation.

Balancing Algorithms

Round Robin — requests are distributed across servers in turn. Weighted Round Robin — more powerful servers receive more requests. Least Connections — the request is sent to the server with the fewest active connections. IP Hash — requests from the same client always go to the same server (important for sessions). Health Check — non-functioning servers are automatically removed from the pool.

Balancing Levels

Balancing can operate at different levels. L4 (transport) — distribution at the TCP/UDP level, fast and simple. L7 (application) — distribution at the HTTP level, with the ability to route by URL, headers, and cookies. In practice, both levels are often used: L4 at the entry point (NGINX, HAProxy) and L7 for finer-grained routing (Ingress Controller in Kubernetes).

Load Balancing in Webparadox Projects

For e-commerce and high-load projects, we design infrastructure with load balancing from day one. We use NGINX and HAProxy for L4/L7 balancing, Kubernetes Ingress for containerized applications, and cloud load balancers (AWS ALB, DigitalOcean Load Balancer) for automatic scaling. Combined with CDN and caching, this ensures stable operation even during peak loads.