# Day array to vu for scenario

**URL:** <https://community.grafana.com/t/day-array-to-vu-for-scenario/159682>\
**Category:** OSS Support\
**Created:** [November 25, 2025, 11:21am UTC](https://community.grafana.com/t/day-array-to-vu-for-scenario/159682 "2025-11-25T11:21:56Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![fenchu](https://sea2.discourse-cdn.com/grafana/user_avatar/community.grafana.com/fenchu/32/44330_2.png) [@fenchu](https://community.grafana.com/u/fenchu)\
**Post date:** [November 25, 2025, 11:21am UTC](https://community.grafana.com/t/day-array-to-vu-for-scenario/159682/1 "2025-11-25T11:21:56Z")

</div>

How can I convert my array into a list that take one vu for each day in the days array

```auto
export default function () {
    let days = [];
    const first = dayjs();
    const last = first.clone().add(3, 'month');

    for(let d=first.clone(); d<last; d=d.add(1, 'day') ) {
        days.push(d);
    }
    for(let d of days) {
        <run my test scenario>
    }

```

How can I take one line from the days array so I can run it as a vu?

The solution I’m testing is independent on day.

Test is all fine, it is the report that only show one vu.

---

<div class="post-metadata">

**Author:** ![fenchu](https://sea2.discourse-cdn.com/grafana/user_avatar/community.grafana.com/fenchu/32/44330_2.png) [@fenchu](https://community.grafana.com/u/fenchu)\
**Post date:** [November 26, 2025, 11:13am UTC](https://community.grafana.com/t/day-array-to-vu-for-scenario/159682/2 "2025-11-26T11:13:47Z")

</div>

I have it fixed using a single redis key since ‘INCR’ is atomic,  
But the first scenario `first`runs twice, even if it is `vu:1, iteration:1`  
and is it possible to just let them run after each other without adding the delayed `startTime: '1s'`

```auto
import dayjs from '../tools/dayjs.min.js';
import utc from '../tools/dayjs-plugin-utc.min.js';
// inject utc plugin to dayjs
dayjs.extend(utc);
import redis from 'k6/x/redis';
const redisClient = new redis.Client(
    // URL in the form of redis[s]://[[username][:password]@][host][:port][/db-number
    __ENV.REDIS_URL || "redis://127.0.0.1:6379",
);
const redisKey = 'hvdc-k6-date-vu-pos';

let days = [];
const first = dayjs();
const last = first.clone().add(1, 'month');
for(let d=first.clone(); d<last; d=d.add(1, 'day') ) {
    days.push(d.format('YYYY-MM-DD'));
}

export const options = {
    scenarios: {
        first: {
            executor: 'shared-iterations',
            vus: 1,
            iterations: 1,
            exec: 'setup',
        },
        test: {
            executor: 'shared-iterations',
            vus: 10,
            iterations: 30,
            exec: 'default',
            startTime: '1s'
        },
    },
};

export async function setup() {
    await redisClient.set(redisKey, 0);
    console.log(`initialize key '${redisKey}'`);
};

export default async function() {
    let myday = undefined;
    const exists = await redisClient.exists(redisKey);
    if (exists === false) {
        throw new Error(`${redisKey} should exist`);
    }
    let r = parseInt(await redisClient.incr(redisKey));
    if(typeof(r)!== 'undefined' && r+1<=days.length) {
        myday = days[r-1];
        console.log(`doing ${myday}`);
    }
};

```

Why first scenario twice?

> $ k6 -q run test/test-scenario.js  
> INFO[0000] initialize key ‘hvdc-k6-date-vu-pos’ source=console  
> INFO[0000] initialize key ‘hvdc-k6-date-vu-pos’ source=console  
> INFO[0001] doing 2025-11-28 source=console  
> INFO[0001] doing 2025-11-27 source=console  
> INFO[0001] doing 2025-11-29 source=console  
> INFO[0001] doing 2025-11-30 source=console  
> INFO[0001] doing 2025-12-01 source=console  
> INFO[0001] doing 2025-12-04 source=console  
> INFO[0001] doing 2025-12-02 source=console  
> INFO[0001] doing 2025-12-05 source=console  
> INFO[0001] doing 2025-12-03 source=console  
> INFO[0001] doing 2025-12-06 source=console  
> INFO[0001] doing 2025-12-10 source=console  
> INFO[0001] doing 2025-12-09 source=console  
> INFO[0001] doing 2025-12-12 source=console  
> INFO[0001] doing 2025-12-07 source=console  
> INFO[0001] doing 2025-12-15 source=console  
> INFO[0001] doing 2025-12-08 source=console  
> INFO[0001] doing 2025-12-14 source=console  
> INFO[0001] doing 2025-12-13 source=console  
> INFO[0001] doing 2025-12-11 source=console  
> INFO[0001] doing 2025-12-17 source=console  
> INFO[0001] doing 2025-12-18 source=console  
> INFO[0001] doing 2025-12-19 source=console  
> INFO[0001] doing 2025-12-16 source=console  
> INFO[0001] doing 2025-12-25 source=console  
> INFO[0001] doing 2025-12-21 source=console  
> INFO[0001] doing 2025-12-23 source=console  
> INFO[0001] doing 2025-12-22 source=console  
> INFO[0001] doing 2025-12-20 source=console  
> INFO[0001] doing 2025-12-24 source=console  
> INFO[0001] doing undefined source=console

---

<div class="post-metadata">

**Author:** ![fenchu](https://sea2.discourse-cdn.com/grafana/user_avatar/community.grafana.com/fenchu/32/44330_2.png) [@fenchu](https://community.grafana.com/u/fenchu)\
**Post date:** [December 2, 2025, 1:46pm UTC](https://community.grafana.com/t/day-array-to-vu-for-scenario/159682/3 "2025-12-02T13:46:58Z")

</div>

I found the issue with the first scenario running twice, because it is called `setup()`  
if there is a `setup()` it is always ran before the scenarios starts. So I just rename it.

So now it is perfect I can set VUS=60 and it will pick unique days. and each only once.