How to inject random no. of users in Gatling?

Question

I would like to inject random no. of users in Gatling. For example,

For first 10 secs, 100 users

For next 15 secs, 25 users,

For next 2 secs, 1000 users and so on..

random time with random number of users

One complex workaround I have found is as follows:

val r=new scala.util.Random
  setUp(
    scn.inject(

         constantUsersPerSec(10) during(10 seconds) randomized,
             constantUsersPerSec(10+r.nextInt(500)) during(15 seconds) randomized,
             constantUsersPerSec(210+r.nextInt(500)) during(25 seconds) randomized,
             constantUsersPerSec(510+r.nextInt(520)) during(55 seconds) randomized,
             constantUsersPerSec(170+r.nextInt(100)) during(5 seconds) randomized,
             constantUsersPerSec(270+r.nextInt(1010)) during(5 seconds) randomized,
             constantUsersPerSec(710+r.nextInt(5100)) during(1 minute) randomized,
             constantUsersPerSec(5+r.nextInt(40)) during(100 seconds) randomized,
             constantUsersPerSec(710+r.nextInt(5200)) during(15 seconds) randomized,
             constantUsersPerSec(0+r.nextInt(20)) during(10 seconds) randomized,


         constantUsersPerSec(10) during(10 seconds) randomized,
             constantUsersPerSec(10+r.nextInt(500)) during(15 seconds) randomized,
             constantUsersPerSec(210+r.nextInt(500)) during(25 seconds) randomized,
             constantUsersPerSec(510+r.nextInt(520)) during(55 seconds) randomized,
             constantUsersPerSec(170+r.nextInt(100)) during(5 seconds) randomized,
             constantUsersPerSec(270+r.nextInt(1010)) during(5 seconds) randomized,
             constantUsersPerSec(710+r.nextInt(5100)) during(1 minute) randomized,
             constantUsersPerSec(5+r.nextInt(40)) during(100 seconds) randomized,
             constantUsersPerSec(710+r.nextInt(5200)) during(15 seconds) randomized,

             constantUsersPerSec(1) during(10 seconds),

           ).protocols(kafkaConf))

Is there any simple way to do this?

In other words, is there any way to inject in a loop?

PS: I tried the repeat() for a scenario, but that is a different thing altogether. Instead of calling once, it calls n times ie it does the action n times for every user.

Answer 1

the .inject method can take an array of injection steps, so you can just use a function to generate that array

val r=new scala.util.Random

setUp(
    scn.inject(
        (1 to 10).map(i => constantUsersPerSec(r.nextInt(500)) during (r.nextInt(30) seconds) randomized)
    )
).protocols