Is there a way to use 3 different flows randomly accross virtual users?

Grafana k6 OSS Support
1

Hi,

I have 3 flows ready and I want them to be assigned randomly for each iteration, how do I design this?

Example:
I have 10 VUs executing script(s)
I have 3 flows
FIRST execution of 10 VUs:
4 users used 1.flow
3 users used 2.flow
3 users used 3.flow and so on.
SECOND execution of 10 VUs:
2 users used 1.flow
6 users used 2.flow
2 users used 3.flow and so on

Is there a way I could do this in one script only?

Thank you in advance!

3

Hi @Explorit

Welcome to the community forum :wave:

Without more details of your case, I would say maybe it does not matter if it’s the same VU that executes the flows, and that you might get a similar result combining scenarios or with other mechanisms. If what you need to achieve is a “random” number of executions for different flows/scenarios, and not that each VU changes the flow randomly after each iteration.

If you haven’t read those yet, I recommend a read of k6 testing guides depending on your use case:

That said, I’m thinking you can achieve what you described with a script similar to the one below (or any alternatives, like a switch/case inside the default function):

import exec from 'k6/execution';
import { sleep } from 'k6';
import { randomIntBetween } from 'https://jslib.k6.io/k6-utils/1.2.0/index.js';

export const options = {
    vus: 2,
    duration: "10s",
};

var flows = [flow_zero, flow_one, flow_two];

function flow_zero() {
    console.log('VU: ', exec.vu.idInTest, 'Iteration: ', exec.vu.iterationInInstance, 'flow 0');
}

function flow_one() {
    console.log('VU: ', exec.vu.idInTest, 'Iteration: ', exec.vu.iterationInInstance, 'flow 1');
}

function flow_two() {
    console.log('VU: ', exec.vu.idInTest, 'Iteration: ', exec.vu.iterationInInstance, 'flow 2');
}

export default function () {
    let i = randomIntBetween(0, flows.length - 1);
    flows[i]();
    sleep(1);
}

Executing this, we get random flows executed randomly on each VU iteration.

  scenarios: (100.00%) 1 scenario, 2 max VUs, 40s max duration (incl. graceful stop):
           * default: 2 looping VUs for 10s (gracefulStop: 30s)

INFO[0000] VU:  2 Iteration:  0 flow 2                   source=console
INFO[0000] VU:  1 Iteration:  0 flow 1                   source=console
INFO[0001] VU:  2 Iteration:  1 flow 2                   source=console
INFO[0001] VU:  1 Iteration:  1 flow 0                   source=console
INFO[0002] VU:  2 Iteration:  2 flow 1                   source=console
INFO[0002] VU:  1 Iteration:  2 flow 1                   source=console
INFO[0003] VU:  1 Iteration:  3 flow 2                   source=console
INFO[0003] VU:  2 Iteration:  3 flow 0                   source=console
INFO[0004] VU:  1 Iteration:  4 flow 2                   source=console
INFO[0004] VU:  2 Iteration:  4 flow 2                   source=console
INFO[0005] VU:  1 Iteration:  5 flow 1                   source=console
INFO[0005] VU:  2 Iteration:  5 flow 2                   source=console
INFO[0006] VU:  1 Iteration:  6 flow 0                   source=console
INFO[0006] VU:  2 Iteration:  6 flow 2                   source=console
INFO[0007] VU:  2 Iteration:  7 flow 2                   source=console
INFO[0007] VU:  1 Iteration:  7 flow 0                   source=console
INFO[0008] VU:  2 Iteration:  8 flow 1                   source=console
INFO[0008] VU:  1 Iteration:  8 flow 2                   source=console
INFO[0009] VU:  2 Iteration:  9 flow 2                   source=console
INFO[0009] VU:  1 Iteration:  9 flow 1                   source=console

     data_received........: 0 B 0 B/s
     data_sent............: 0 B 0 B/s
     iteration_duration...: avg=1s min=1s med=1s max=1s p(90)=1s p(95)=1s
     iterations...........: 20  1.997874/s
     vus..................: 2   min=2      max=2
     vus_max..............: 2   min=2      max=2


running (10.0s), 0/2 VUs, 20 complete and 0 interrupted iterations
default ✓ [======================================] 2 VUs  10s

I hope this helps.

Cheers!