Previous: Provisioning PostgreSQL RDS

It would not be a complete infrastructure setup without some load testing. We have built this beautiful infrastructure that does pretty much nothing. But how much user load can it handle? Let's find out!

Using k6 for Load Testing

We are going to use k6 - a modern load testing tool that makes it easy to script and run load tests. First, install k6 by following the instructions on their installation page.

Writing a Load Test Script

We are going to create a simple load test script that hits our web application's domain. Create a file named load-test.js with the following content:

We are going to simulate 10000 virtual users (VUs) over a period of 20 seconds, sending requests to our web application's domain.

The following is the script content that you should put in load-test.js:

import http from 'k6/http';
import { sleep } from 'k6';
export const options = {
  vus: 10000,
  duration: '20s',
};
export default function () {
  http.get('http://www.your-domain.com');
  sleep(1);
}

Running the Load Test

You can run the load test using the following command:

k6 run load-test.js

The test will start, after it finishes, the json file will be created and you will see real-time statistics about the requests being made, response times, and any errors encountered.

Analyzing the Results

The JSON output file can be analyzed using various tools. One popular option is to use Grafana along with k6 Cloud. You can also use the built-in summary report that k6 provides at the end of the test run.

I have made a simple web app to render the results, and here is a sample screenshot of how the results might look:

You can see that our infrastructure did not handle the 10000 users very well! Outch!

This is expected since we did not setup auto-scaling, or caching, and only had two EC2 instances running. In a production scenario, you would want to implement these features to handle high traffic loads effectively.

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