L4/L7 Load Balancing in Go: DSR & API Gateway Design
Answer-First: Building a Go API gateway with Envoy and NGINX enables L7 load balancing, JWT authentication, and token-bucket rate limiting at the ingress layer. Prerequisite: Part 2 of the System Design Masterclass. Read Part 1: System Design Thinking first. Load Balancing L4/L7 in Go — DSR, Rate Limiting & API Gateway Executive Summary & Quick Answer: L4 load balancing routes traffic at the transport layer using IP/TCP metadata with minimal CPU overhead, whereas L7 load balancing inspects HTTP headers, cookies, and URLs for intelligent content-based routing. Combining L4 Direct Server Return (DSR) with L7 Envoy API Gateways and Go token-bucket rate limiters handles peak traffic spikes smoothly. ...