Track transmitted data per URL

1import http from 'k6/http';
2import { sleep } from 'k6';
3import { Counter } from 'k6/metrics';
4
5// Two custom metrics to track data sent and received. We will tag data points added with the corresponding URL
6// so we can filter these metrics down to see the data for individual URLs and set threshold across all or per-URL as well.
7export const epDataSent = new Counter('endpoint_data_sent');
8export const epDataRecv = new Counter('endpoint_data_recv');
9
10export const options = {
11  duration: '10s',
12  vus: 10,
13  thresholds: {
14    // We can setup thresholds on these custom metrics, "count" means bytes in this case.
15    'endpoint_data_sent': ['count < 2048'],
16
17    // The above threshold would look at all data points added to the custom metric.
18    // If we want to only consider data points for a particular URL/endpoint we can filter by URL.
19    'endpoint_data_sent{url:https://test.k6.io/contacts.php}': ['count < 1024'],
20    'endpoint_data_recv{url:https://test.k6.io/}': ['count < 2048'], // "count" means bytes in this case
21  },
22};
23
24function sizeOfHeaders(hdrs) {
25  return Object.keys(hdrs).reduce((sum, key) => sum + key.length + hdrs[key].length, 0);
26}
27
28function trackDataMetricsPerURL(res) {
29  // Add data points for sent and received data
30  epDataSent.add(sizeOfHeaders(res.request.headers) + res.request.body.length, {
31    url: res.url,
32  });
33  epDataRecv.add(sizeOfHeaders(res.headers) + res.body.length, {
34    url: res.url,
35  });
36}
37
38export default function () {
39  let res;
40
41  res = http.get('https://test.k6.io/');
42  trackDataMetricsPerURL(res);
43
44  res = http.get('https://test.k6.io/contacts.php');
45  trackDataMetricsPerURL(res);
46
47  sleep(1);
48}