Load Balancer: The Traffic Cop of High Scale Systems (L4 vs L7)

Round Robin, Least Connections, IP Hash explained. The difference between L4 (Layer 4) and L7 (Layer 7) load balancing, and how to configure Nginx as a Reverse Proxy.

June 2, 2025

Codemapo

Computer Science·May 22, 2025

Keep-Alive: Don't hang up yet

Establishing TCP connection is expensive. Reuse it for multiple requests.

#CS#Web#HTTP#Optimization

Computer Science·May 18, 2025

WebSocket: Escape from Refresh Hell

HTTP is Walkie-Talkie (Over). WebSocket is Phone (Hello). The secret tech behind Chat and Stock Charts.

#CS#Web#WebSocket#Network

Computer Science·March 10, 2026

API Versioning Strategies: URL vs Header vs Content Negotiation

Once you ship a public API, you can't change it freely. Compare four versioning strategies for evolving APIs without breaking clients, plus analysis of real-world choices by GitHub, Stripe, and Twilio.

#API Design#REST#Versioning#Backend

API Versioning Strategies: URL vs Header vs Content Negotiation

Computer Science·May 1, 2025

TCP/IP 4 Layers: Reality Check

OSI 7 Layer is Theory. TCP/IP 4 Layer is Reality. Pragmatism beats Perfectionism.

#CS#Network#TCP/IP#Protocol

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11. Summary: What I Learned from Load Balancers

The core insights I gained from load balancers:

Scaling out is easy, distributing traffic is hard. Without load balancers, scale-out is meaningless.
L4 vs L7 is a "performance vs features" tradeoff. L7 isn't always better.
Avoid Sticky Sessions, embrace Stateless Architecture. Sessions belong in external stores like Redis.
Without Health Checks and Connection Draining, zero-downtime deployment is impossible.
Load balancers can die too. Eliminate SPOF by making load balancers redundant.

One-line summary: "Load balancers aren't just traffic distribution tools. They're core components of high-availability systems."