Load Balancers
Enforcing highly available networks by routing requests dynamically across cluster nodes — covers L4/L7 balancing, Round-Robin, Least Connections, IP Hashing, DNS-level load balancing, and Anycast Routing.
What you'll learn
- Round Robin
- Least Connections
- IP Hashing
- Health Checks
TL;DR
Enforcing highly available networks by routing requests dynamically across cluster nodes — covers L4/L7 balancing, Round-Robin, Least Connections, IP Hashing, DNS-level load balancing, and Anycast Routing.
Visual System Topology
How a Load Balancer Works
Concept Overview
A load balancer distributes incoming network traffic across multiple servers, ensuring no single server is overwhelmed. It's essential for horizontal scaling, high availability, and fault tolerance.
Load balancers can be hardware (F5, Citrix) or software (Nginx, HAProxy), and operate at different network layers (Layer 4 or Layer 7).
Key Architectural Pillars
Round Robin
Distributes requests evenly to each server in rotation. Simple but doesn't account for server load.
Least Connections
Routes to server with fewest active connections. Better for long-running requests.
IP Hashing
Routes based on client IP hash. Ensures same client always hits same server (sticky sessions).
Health Checks
Periodically ping servers to ensure they're healthy. Remove unhealthy servers from rotation.