> For the complete documentation index, see [llms.txt](https://ondrej-kvasnovsky-2.gitbook.io/nodejs-handbook/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ondrej-kvasnovsky-2.gitbook.io/nodejs-handbook/performance-testing.md).

# Performance Testing

## Using Tools

[AB](https://httpd.apache.org/docs/2.4/programs/ab.html) is Apache HTTP server benchmarking tool.

[Siege](https://github.com/JoeDog/siege) is http load and benchmarking utility.

## Custom Solution

We usually want to generate a load for our services to measure the performance. Usually we want to do a certain set of operations every second, 5th second, minute or so.

We are going to create script that will try to call REST API 5 times every second.

```
const _ = require('lodash');
const cron = require('node-cron');
const axios = require('axios');

let sent = 0;
let received = 0;
let inProgress = 0;

console.log("Starting...");
const reportStatus = function (values) {
    let report = '';
    values.forEach(response => {
        if (_.has(response, 'status')) {
            report += response.status + ', ';
        } else if (_.has(response, 'code')) {
            report += response.code + ', ';
        } else {
            report += response.response.status + ', ';
        }
    })
    console.log(`Report: ${report}`);
    received += values.length;
    inProgress -= values.length;
    console.log(`Sent: ${sent}, Received: ${received}, InProgress: ${inProgress}`);
};
const createTasks = function () {
    let howMany = 5;
    const tasks = _.range(0, howMany).map(it => {
        return axios.get('https://api.github.com/search/repositories?q=github&page=1&per_page=1')
    });
    return tasks;
};
const task = cron.schedule('* * * * * * *', function () {
    console.log(new Date());
    const tasks = createTasks();
    let howMany = tasks.length;
    sent += howMany;
    inProgress += howMany;
    console.log(`Sent: ${sent}, Received: ${received}, InProgress: ${inProgress}`);

    Promise.all(tasks.map(p => p.catch(e => e)))
        .then(function (values) {
            reportStatus(values);
        });
});

task.start();
```

When we run the code, we can observe that couple of requests and with 200 but the rest will end with 403, becuase github will refuse too many requests.

> You can authenticate to make more requests.

```
Starting...
2018-02-13T22:17:17.825Z
Sent: 5, Received: 0, InProgress: 5
Report: 200, 200, 200, 200, 200, 
Sent: 5, Received: 5, InProgress: 0
2018-02-13T22:17:18.830Z
Sent: 10, Received: 5, InProgress: 5
Report: 200, 200, 200, 200, 200, 
Sent: 10, Received: 10, InProgress: 0
2018-02-13T22:17:19.833Z
Sent: 15, Received: 10, InProgress: 5
Report: 403, 403, 403, 403, 403, 
Sent: 15, Received: 15, InProgress: 0
2018-02-13T22:17:20.837Z
Sent: 20, Received: 15, InProgress: 5
Report: 403, 403, 403, 403, 403, 
Sent: 20, Received: 20, InProgress: 0
```

The code should also report how each request time and what is median, average and lets say 99th percentile.