Randomized the User Rampup

Hi Team,
I have script where i would like to randomized the users for injection and want to use like below but unable to use and its throwing the error,i am not sure i am doing wrong.

rampUsers(10) during(5) randomized

i tried to see the Open model document details but only 2 options are available as below and its not able to match requirements.


could you please help and advise.


Hi @ksanty1978,

As written in the documentation Injection - Open model, there is no randomized modifier when using rampUsers.

If I try to rephrase your need with my own word, you want to have such modifier to be able to have a known amount of users injected during a specified duration but without knowing the duration between each user? (for now, the users are injected at fixed duration).

I, personally, think it can be interesting for the community. My vote will go to such a contribution!
But be aware that can go very wrong if not taken with constraints:

For instance, consider:

rampUsers(1000) during(1.hour)

It means a user by 3.6seconds.
If we add the randomized modifier, it can mean 1000 users in the first minute for one run. That can be disastrous.
We need to define “limits”. and such limits should be configurable as well.
Can be pretty hard to have a readable DSL for that.

On the other hand, you can change your own way.


var totalUsers = 10
var durationInSeconds = 5

rampUsers(totalUsers) during(durationInSeconds)

can be rewriten as:

var userPerSeconds = totalUsers / durationInSeconds

That last line may have the randomized modifier
Note: I didn’t ensure Int / Float / Double (about integer division vs floating point…)

I hope that helps

Hello Sébastien,
Thanks so much for your reply and detailed information.
Let me try to implement and see how it behaves and result.

once again many thanks for your input