Deep dive handbook

Reliability and performance tests

Runnable example of load test

Script and how to run

The following script, executed with tool k6 , simulates a basic load test:

script.js

import http from 'k6/http';
import { sleep } from 'k6';

export const options = {
  stages: [
    { duration: '20s', target: 50 },
    { duration: '3m', target: 50 },
    { duration: '20s', target: 0 },
  ],
  thresholds: {
    http_req_failed: ['rate<0.01'],
    http_req_duration: ['p(95)<1000'],
  },
};

export default function () {
  const url = 'https://quickpizza.grafana.com';

  http.get(`${url}/contacts.php`);
  sleep(1);

  http.get(`${url}/news.php`);
  sleep(1);
}

Install tool k6 and download script.js , then run it locally with:

  k6 run script.js

Analysis

After being run k6 produces result .

Test summary

Script simulated traffic to https://quickpizza.grafana.com:

• contacts.php
• news.php

Load pattern:

• Ramp-up: 0 to 50 VUs in 20s
• Sustained: 50 VUs for 3m
• Ramp-down: 50 to 0 VUs in 20s

Total duration: ~3m41,8s. 4452 iterations completed, ~20 iterations/sec.

Observed behavior

• Application responded consistently under load.
• No HTTP request failures observed (0,00% failure rate).
• 95% of requests completed within 152,3ms (well below 1s threshold).

Metrics highlights

• Response time:
  Avg: 132,93ms, p(90): 135,1ms, p(95): 152,3ms, Max: 3,98s
• Request rate:
  39,96 requests/sec overall
• Iterations:
  4432 iterations (avg iteration ~2,27s)

Data transferred

• Received: 13 MB (~59 kB/s)
• Sent: 1,4 MB (~6,3 kB/s)

Overall analysis

Thresholds met:

• p(95)<1000ms: 152,3ms
• HTTP failures <1%: 0%

Performance stable under 50 concurrent users.

Suggestions and takeaways

Good performance baseline — the service is performant under moderate load.

Next steps:

• Test higher loads (e.g., 100+ VUs) for scalability limits.
• Add checks/assertions to validate content correctness.
• Monitor backend resource utilization (CPU, memory) alongside k6 metrics.