A simple Load Balancer

Least Connections

This Go program demonstrates a basic load balancer that distributes incoming HTTP requests among a set of backend servers. The load balancer checks the health of each server through periodic health checks and adjusts the load distribution accordingly.

I've kept the files s1, s2 and s3 to quickly spin up test servers on ports 8081, 8082 and 8083 respectively.

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Table of Contents

• Overview
• Features
• Getting Started
• Configuration
• Health Checks
• Load Balancing Strategy
• Customization
• Running the Program
• Contributing

Overview

The code defines a Server struct representing a backend server and a Config struct for configuring the load balancer. The main program initializes servers, performs health checks, and distributes incoming requests based on the least active connections.

Features

Periodic health checks to determine server health. Round-robin load balancing strategy among healthy servers. Configurable parameters via a JSON configuration file.

Getting Started

1. Clone the repository:

git clone https://github.com/yourusername/load-balancer-go.git

2. Navigate to the project directory:

cd load-balancer-go

3. Run the program:

go run main.go

Configuration

The load balancer reads its configuration from a config.json file. Example configuration:

{
  "healthCheckInterval": "5s",
  "servers": ["http://localhost:8081", "http://localhost:8082"],
  "listenPort": ":8080"
}

• healthCheckInterval: The interval between health checks.
• servers: An array of backend server URLs.
• listenPort: The port on which the load balancer listens.

Health Checks

Health checks are performed at regular intervals to assess the status of each backend server. Unhealthy servers (status code >= 500 or errors during health check) are temporarily excluded from load balancing.

Load Balancing Strategy

The load balancer uses a round-robin strategy among healthy servers to distribute incoming requests. The server with the least active connections is chosen for each request.

Customization

Feel free to customize the code according to your requirements. You can modify health check intervals, add more backend servers, or implement different load balancing strategies.

Running the Program

Ensure Go is installed on your machine. Execute go run main.go in the project directory. Access the load balancer at http://localhost:8080 (or the specified listenPort). Contributing Contributions are welcome! Fork the repository, make your changes, and submit a pull request.