Load Balancer Simulation ⚡

A high-performance C++ simulation of a Layer 4/7 Load Balancer, demonstrating core networking concepts, request routing strategies, and server health management through a command-line interface.

🚀 Features

• Dynamic Server Management: Add or remove backend servers in real-time.
• Round-Robin Strategy: Balanced request distribution across active servers.
• Health Monitoring: Track server status, active connections, and capacity limits.
• Request Simulation: Route simulated client requests with custom payloads and IPs.
• Modern C++ Architecture: Utilizes Strategy Pattern for extensible load balancing algorithms.

📂 Project Structure

Load Balancer/
├── src/                # Implementation files
│   ├── Balancer.cpp    # Core logic for request routing
│   ├── Request.cpp     # Request object lifecycle
│   └── Server.cpp      # Backend server simulation
├── utils/              # Header files and strategies
│   ├── Balancer.h      # Balancer class definition
│   ├── Server.h        # Server class definition
│   ├── Request.h       # Request data structure
│   ├── RoundRobin.h    # Round Robin strategy implementation
│   └── LoadBalancingStrategy.h # Strategy Interface
├── main.cpp            # CLI Entry point
└── CMakeLists.txt       # Build configuration

🛠️ Build and Run

Prerequisites

• C++ Compiler (supporting C++17)
• CMake (v3.10 or higher)

Using CMake

1. Create a build directory:

   mkdir build
   cd build

2. Configure and build:

   cmake ..
   cmake --build .

3. Run the executable:

   .\LoadBalancer.exe

Manual Compilation (Alternative)

If you have g++ installed, you can compile directly:

g++ main.cpp src/Balancer.cpp src/Request.cpp src/Server.cpp -I utils -o LoadBalancer.exe

🎮 CLI Usage

Once the simulation starts, you can interact with it using the following commands:

Command	Usage	Description
add	add <ip> <port> <name>	Registers a new backend server.
route	route <clientIP> <payload>	Simulates an incoming request.
status	status	Displays active servers, health, and current load.
remove	remove <port>	Removes a server from the rotation by its port.
help	help	Shows available commands.
exit	exit	Closes the simulation.

🧠 Key Concepts

Load Balancing Strategy

The project implements the Strategy Pattern. Currently, it uses Round Robin, but the architecture allows for easy integration of new strategies (e.g., Least Connections, IP Hash) by implementing the LoadBalancingStrategy interface.

Server Lifecycle

Each Server object maintains a queue of activeRequests and tracks currentConnections vs maxConnections. Servers can be marked with different health statuses, affecting how the balancer interacts with them.

---

Developed with modern C++ for low-latency simulation.