Custom Load Balancer in Go with Real-Time Visualization

This project implements a custom software-based load balancer in Go, complete with a real-time dashboard visualization. It dynamically distributes incoming HTTP requests across multiple backend servers using the Least Connections algorithm.

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High-Level Project Overview

1. Backend Servers: Simple Go HTTP servers that handle incoming requests and respond after a configurable delay.
2. Custom Load Balancer: A Go-based load balancer that forwards incoming HTTP requests to backend servers.
3. Health Checks: Periodically checks if backend servers are healthy and dynamically removes unhealthy servers from rotation.
4. Visualization Dashboard: A real-time dashboard built with HTML, JavaScript, and Chart.js to visualize server load and health status.
5. AWS Infrastructure: Deployment of backend servers and load balancer onto AWS EC2 instances.
6. Nginx Reverse Proxy: Nginx server set up as a reverse proxy in front of the Go load balancer to provide standard HTTP port access, SSL termination, and efficient static content serving.
7. Load Testing: Using tools like ApacheBench (ab) or Siege to simulate real-world traffic and verify correct load distribution.

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Technologies Used

Technology	Purpose
Go	Backend & Load Balancer logic
Nginx	Reverse proxy & static content serving
AWS EC2	Cloud hosting infrastructure
Systemd	Service management
Apache Bench (ab), curl	Load testing
Chart.js	Real-time visualization
HTML/CSS/JavaScript	Dashboard frontend

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Development Steps

Step 1: Backend Servers Setup

• Write simple HTTP servers in Go.
• Implement /health endpoint for health checks.
• Include artificial delays for testing purposes.

Step 2: Load Balancer Implementation

• Implemented in Go, using the Least Connections algorithm.
• Regularly performs health checks on backend servers.
• Provides API endpoints for real-time statistics visualization.

Step 3: Visualization Dashboard

• HTML dashboard using Chart.js to visualize active connections per server.
• Fetches real-time data from /api/server-stats endpoint provided by the load balancer.

Step 4: AWS Deployment

• Deploy backend servers and load balancer on separate EC2 instances.
• Configure security groups to allow necessary traffic (HTTP ports).

Step 5: Nginx Reverse Proxy Setup

• Installed on the load balancer instance.
• Forwards HTTP requests from port 80 to the Go application running on port 8080.

Step 6: Load Testing & Monitoring

• Use Apache Bench (ab) or Siege to simulate high traffic scenarios.
• Monitor real-time server loads through the visualization dashboard.

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How the Load Balancing Algorithm Works (Least Connections Algorithm)

The implemented algorithm is called "Least Connections," a dynamic load balancing method that distributes incoming requests based on the current number of active connections each backend server has:

• When a new request arrives, the load balancer checks all available and healthy backend servers.
• It selects the server currently handling the fewest active connections.
• The request is forwarded to this selected server, incrementing its active connection count.
• Once the request completes (and after an optional delay), the active connection count is decremented.

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