Round Robin

ELI5 — The Vibe Check

Round Robin is the simplest load balancing strategy: send request 1 to server A, request 2 to server B, request 3 to server C, then back to server A, and so on. Everyone gets equal turns, like dealing cards in a card game. Simple but doesn't account for server load.

Real Talk

Round Robin is a load balancing algorithm that cycles through backend servers in order, distributing each new request to the next server in the list. Simple to implement with even distribution, but doesn't account for varying request complexity or server capacity. Weighted Round Robin adds server weights.

Show Me The Code

# Nginx round-robin (default algorithm)
upstream backend {
  server app1.example.com;  # Gets request 1, 4, 7...
  server app2.example.com;  # Gets request 2, 5, 8...
  server app3.example.com;  # Gets request 3, 6, 9...
}

# Weighted round-robin
upstream weighted_backend {
  server app1.example.com weight=3;  # Gets 60% of traffic
  server app2.example.com weight=2;  # Gets 40% of traffic
}

When You'll Hear This

"The load balancer uses round robin to distribute requests evenly." / "Weighted round robin sends more traffic to the bigger server."