Scaling Load Testing with TypeScript on a Zero Budget

Handling massive load testing is a critical challenge in software development, especially when resources are limited. In this article, we explore how a security researcher leveraged TypeScript and open-source tools to design an efficient, scalable load testing framework without any additional budget.

The Challenge

Traditional load testing tools like Apache JMeter or commercial solutions often come with hefty licensing costs or scalability limitations, especially in resource-constrained environments. The goal was to create a lightweight, maintainable, and scalable solution using only free, open-source technologies that anyone can replicate.

Why TypeScript?

TypeScript offers strong typing, modern syntax, and excellent tooling support, making it ideal for building robust testing frameworks. Its compatibility with Node.js allows easy deployment and scaling across different environments.

Designing a Zero-Budget Load Tester

The core idea was to utilize Node.js's asynchronous capabilities to simulate a high volume of requests efficiently. We combined TypeScript with libraries like axios for HTTP requests and cluster for parallel execution.

Setting Up the Environment

First, initialize a new project:

mkdir load-tester && cd load-tester
npm init -y
npm install typescript axios
npx tsc --init

Ensure your tsconfig.json includes:

{
  "compilerOptions": {
    "target": "ES6",
    "module": "CommonJS",
    "outDir": "dist",
    "esModuleInterop": true
  }
}

Basic Load Test Script

Here's a simple example (loadTest.ts) that performs high concurrency requests:

import axios from 'axios';
import { cpus } from 'os';
import { Worker, isMainThread, parentPort } from 'worker_threads';

const URL = 'https://your-target-url.com/api/test';
const concurrency = 1000; // Number of parallel requests
const totalRequests = 10000; // Total requests to perform

async function sendRequest() {
  try {
    const response = await axios.get(URL);
    return response.status;
  } catch (error) {
    return error.response?.status || 500;
  }
}

async function performLoad() {
  const promises = [];
  for (let i = 0; i < totalRequests; i++) {
    promises.push(sendRequest());
    if (promises.length >= concurrency) {
      await Promise.all(promises);
      promises.length = 0;
    }
  }
  await Promise.all(promises);
  console.log('Load testing completed');
}

if (isMainThread) {
  const numWorkers = cpus().length;
  for (let i = 0; i < numWorkers; i++) {
    new Worker(__filename);
  }
} else {
  performLoad();
  parentPort?.postMessage('done');
}

This script dynamically spawns worker threads based on CPU cores to distribute load, with each thread executing a high number of requests asynchronously.

Scaling and Optimization

• Parallelism: Using Node.js worker threads maximizes CPU utilization.
• Rate Limiting: Incorporate throttling if the target system has rate limits.
• Auto-scaling: Run multiple instances via Docker or serverless setups (e.g., AWS Lambda functions if budget allows) to increase load capacity.

Monitoring and Gathering Results

For real-time metrics, integrate with free monitoring tools like Prometheus, or log response statuses and timings to local files for post-test analysis.

// Extend sendRequest to log response times and status
// Save logs for analysis

This approach emphasizes reproducibility and flexibility, empowering security researchers and developers to perform large-scale load testing without financial investment.

Final Remarks

By creatively leveraging TypeScript and open-source Node.js libraries, it's possible to build an effective load testing framework that scales with your needs—entirely driven by code, with no additional costs. This method underscores the importance of understanding system-level concurrency and harnessing game's operating system features to maximize efficiency.

Embarking on zero-budget solutions requires ingenuity and a deep understanding of existing technologies, but the results can be surprisingly powerful and adaptable to various testing scenarios.

---

🛠️ QA Tip

To test this safely without using real user data, I use TempoMail USA.