Go Load Tester

A high-performance API load testing tool built in Go, inspired by tools like JMeter and hey. Designed to generate concurrent HTTP traffic, measure latency, and produce actionable performance metrics.

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✨ Features

• Concurrent request execution using worker pools

• Configurable total requests and concurrency

• Measures:

  • Total requests
  • Success vs failure
  • Average latency

• Graceful shutdown using context.Context

• Modular, maintainable package structure

• CLI-based usage

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🧱 Project Structure

go-load-tester/
├── cmd/
│   └── loadtester/
│       └── main.go        # Application entry point
├── internal/
│   ├── config/            # Configuration management
│   ├── engine/            # Core load testing engine
│   │   ├── worker.go      # Worker pool logic
│   │   ├── dispatcher.go # Job dispatching
│   │   └── runner.go     # Test orchestration
│   ├── requester/         # HTTP request handling
│   ├── metrics/           # Thread-safe metrics collection
│   └── report/            # Summary report generation
├── go.mod
└── README.md

This structure follows Go best practices:

• Clear separation of concerns
• cmd/ for executable entry points
• internal/ to prevent unwanted imports

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⚙️ How It Works

1. A dispatcher sends jobs into a channel

2. Multiple workers (goroutines) consume jobs concurrently

3. Each worker:

   • Sends an HTTP request
   • Measures response time
   • Records success or failure

4. Metrics are aggregated safely using mutexes

5. A summary report is generated at the end

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🛠️ Installation

Make sure you have Go 1.21+ installed.

git clone https://github.com/JagTheFriend/Load-Testing-Tool.git
cd Load-Testing-Tool
go mod tidy

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▶️ Usage

Run the load tester from the command line:

go run cmd/loadtester/main.go \
  -url https://example.com \
  -n 1000 \
  -c 50

CLI Flags

Flag	Description
-url	Target API endpoint (required)
-n	Total number of requests
-c	Number of concurrent workers

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📊 Sample Output

====== Load Test Report ======
Total Requests: 1000
Successful:     987
Failed:         13
Average Latency:120ms
Test Duration:  3.4s

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🧠 Key Technical Concepts Demonstrated

• Goroutines & channels
• Worker pool pattern
• Thread-safe metrics aggregation
• Context-based cancellation
• Clean package design
• CLI argument parsing

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📈 Possible Enhancements

• P95 / P99 latency calculations
• Support for HTTP headers & request bodies
• JSON / CSV report export
• Rate limiting (RPS control)
• Distributed load generation
• Prometheus-compatible metrics output