Simple PHP Load Balancer

This repository contains a simple load balancer implemented in PHP using the Round-robin scheduling algorithm. It is designed to distribute incoming HTTP requests evenly across a set of servers.

Features

• Round-robin Scheduling: Distributes requests evenly across all available servers.
• Dynamic Server Management: Servers are loaded from a JSON configuration file, allowing easy changes to the server pool without altering the code.
• Request Forwarding: Forwards HTTP methods, headers, and body content to the target server seamlessly.

Prerequisites

• PHP 8.3 or higher
• cURL support enabled in PHP

Installation

1. Clone the repository:

   git clone https://github.com/PatriciaLisboa/simple-load-balancer.git
   

2. Navigate to the repository directory:

   cd simple-load-balancer
   

Configuration

Edit the servers.json file to list the URLs of the servers you want to include in the load balancing pool:

{
    "servers": [
        "http://localhost:8081",
        "http://localhost:8082",
        "http://localhost:8083"
    ]
}

Usage

To start the load balancer, run the following command from the root of your repository:

php -S 0.0.0.0:8080 main.php

This will initiate the load balancer to listen for incoming requests and distribute them among the configured servers.

Example Servers

The repository includes a dummy_server.php file that you can use to simulate a server. To run multiple instances of this server on different ports:

php -S localhost:8081 dummy_server.php 8081 &
php -S localhost:8082 dummy_server.php 8082 &
php -S localhost:8083 dummy_server.php 8083 &

Testing

You can test if the requests are being forwarded to the different servers, you can use cURL:

curl http://localhost:8080

License

This project is open-sourced under the GPL 3 License. See the LICENSE file for more details.