Forget about JMeter, Start writing K6 scripts for Load Testing and Performance Monitoring

1. K6 vs JMeter

# Forget about JMeter, Start writing K6 scripts for Load Testing and Performance Monitoring

Performance testing or monitoring is not new to us. Whenever we create an API, We do need testing. For code and components, We write unit tests and integration tests. However, for performance, We need to load test and monitor the result.


A Gist page for article: [Forget about JMeter, Start writing K6 scripts for Load Testing and Performance Monitoring](https://medium.com/@deepak-v/writing-k6-scripts-for-load-testing-and-performance-monitoring-25cb2aefa23c)

4_1.js

// tests/main.js
import http from "k6/http";
// Take port from env variable
const apiEndpoint = `http://${__ENV.API_HOST}:${__ENV.API_PORT}`;
export default function () {
  http.get(`${apiEndpoint}/users`);
}

4_2.bash

#!/usr/bin/env
REPORT_DATE=$(date +"%Y_%m_%dT%H_%M_%S")
## Define Environment varibles
PORT=3000
API_HOST=0.0.0.0
## Run node app/index.js
PORT=3000 node app/index.js &>/dev/null &
## Get node app pid
api_pid=$!
k6 run -e API_PORT=$PORT -e API_HOST=$API_HOST --config config.json --out csv="reports/report_$REPORT_DATE.csv" tests/main.js
## Kill node app
echo "killing node api"
kill -KILL $api_pid

4_3.json

{
  "stages": [
    { "duration": "5s", "target": 2 },
    { "duration": "2s", "target": 0 }
  ],
  "thresholds": { "http_req_duration": ["avg<100", "p(95)<200"] },
  "noConnectionReuse": true,
  "userAgent": "MyK6UserAgentString/1.0"
}

5_1.js

import http from "k6/http";
// Take port from env variable
const apiEndpoint = `http://${__ENV.API_HOST}:${__ENV.API_PORT}`;
export default function () {
  http.get(`${apiEndpoint}/users`);
}

5_2.js

import http from "k6/http";
// Take port from env variable
const apiEndpoint = `http://${__ENV.API_HOST}:${__ENV.API_PORT}`;
export default function () {
  const randomId = Math.ceil(Math.random() * 99 + 1);
  http.get(`${apiEndpoint}/user/ID_${randomId}`);
}

5_3.js

import { sleep } from "k6";
// import modules
import getAllUsersTest from "./getAllUsers.test.js";
import userByIdTest from "./userById.test.js";
export default function () {
  getAllUsersTest();
  sleep(1);
  userByIdTest();
}