Gatling: Can ramping up of individual scenarios be done just like the users?

Question

Consider an example of testing API's with Gatling. For some weird requirement i had to get a scenario for each user

var scenarioList // This is of type mutable list

I have plenty of scenarios added to this list as my request body should differ for each user or the request won't be processed.This individual scenarios have following gatling simulation configured at this moment

Ex: scenarioList += scenario1. inject(rampUsers(1) over (1 minutes)
    scenarioList += scenario2. inject(rampUsers(1) over (1 minutes)
    scenarioList += scenario3. inject(rampUsers(1) over (1 minutes)
    .
    .
    .
    so on

Now in the global setup as below while calling all these scenarios

setUp(scenarioList: _*).assertions(
    forAll.successfulRequests.percent.gte(90)
  )

Suppose i have 1000 users (scenarioList size is 1000), The problem here would be all of the 1000 users would start at the same time but i want to ramp up these users. So the question comes of ramping up the scenarios instead of running them parallely.

Is this possible ? If not is there any other approach to follow ? I can't have the luxury of running the same scenario with multiple users as the body of the requests change. Please let me know.

Answer 1

I was able to solve this problem by using feeders within the scenario so i don't need to create multiple scenarios.

With feeders Gatling provides option to parameterize your request body of any http request.

Code Example:

  var randomSession = Iterator.continually(Map("randsession" -> ( req.replace("0000000000", randomStringGenerator.randomString(10)))))

  val httpConf = http
    .baseURL("http://localhost:5000")
    .acceptHeader("text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8")
    .userAgentHeader("Mozilla/4.0(compatible;IE;GACv10. 0. 0. 1)")

  val scn = scenario("Activate")
    .feed(randomSession)
    .exec(http("activate request")
    .post("/login/activate")
    .body(StringBody("""${randsession}"""))
    .check(status.is(200)))
    .pause(5)

  setUp(
    scn.inject(atOnceUsers(5))
  ).protocols(httpConf)
}