mauricioabreu / load-balancingo

Load Balancing algorithms in go

Load Balancingo is a hands-on exploration into load balancing algorithms. Dive in to understand how popular mechanisms like Round Robin or Power of Two Choices (P2C) work under the hood.

Highlights

• 📚 Educational Focus: Designed for learning.
• 🔄 Algorithms: Round Robin, P2C, and more illustrated.
• 📊 Metrics: Integrated insights with Prometheus and Grafana.

git clone https://github.com/mauricioabreu/load-balancingo.git
cd load-balancingo
go run main.go

Requirements

You need all these awesome tools below to run this project:

• Go - a good language to build HTTP APIs, workers, daemons and every kind of distribued system service
• hey - awesome loading test tool
• Just - a command runner
• Docker Compose - define and run multiple containers with ease
• Grafana - build charts, dashboards and alerts to observe your systems
• Prometheus - a monitoring system and time series database

Testing

You need the go toolchain installed. Then, run go run main.go in the root directory. This command will start a server in the 8080 port to receive requests. There is one route for each balancing algorithm:

• /rr - Round Robin
• /p2c - Power of Two Choices

You can test the load balancing algorithms by sending requests to the server. For example, using curl:

curl http://localhost:8080/rr

Or

curl http://localhost:8080/p2c

We also provide a justfile with some load testing.

Run just -l to list all available commands.

Algorithms

Round Robin

A uniform/weighted round robin load balancer. Servers are assigned weights, determining selection frequency. Higher weights are favored more. If weights are equal, servers are chosen uniformly.

How it works:

• Servers are assigned weights, determining selection frequency. Higher weights are favored more. If weights are equal, servers are chosen uniformly.
• Keep track of the index of the last server used.
• When a new request comes in, use the next server in the list.
• If the end of the list is reached, start over from the beginning.

Power of Two Choices

A power of two choices (P2C) load balancer. Servers are chosen uniformly at random, and the least loaded server is chosen. This load may be determined by any metric, such as CPU usage, memory usage, or latency.

How it works:

• If the list has only one server, choose that server.
• If the list has two servers, decide between the two based on their load.
• If the list has more than two servers, choose two at random and decide between them.