How to execute a scenario using data from the previous scenario? - stress-testing

Question

I'd like to execute two scenarios that should be executed one after another and the data "produced" by the first scenario should be used as base for the second scenario.
So a case could be for example clearing of a credit card. The first scenarios is there to authorize/reserve of a certain amount on the card:
val auths = scenario("auths").during(durationInMinutes minutes) {
feed(credentials)
.feed(firstNames)
.feed(lastNames)
.feed(cards)
.feed(amounts)
.exec(http("send auth requests")
.post(...)
.check(...))}
The second one is there to capture/take the amount from the credit card:
val caps = scenario("caps").during(durationInMinutes minutes) {
feed(credentials)
.feed(RESPONSE_IDS_FROM_PREVIOUS_SCENARIO)
.exec(http("send auth requests")
.post(...)
.check(...))}
I initially thought about using the saveAs(...) option on check but I figured out that the saved field is only valid for the given session.
So basically I want to preserve the IDs I got from the auths scenario and use them in the caps scenario.
I cannot execute both steps in one scenario though (saveAs would work for that) because I have different requirement for both scenarios.

Answer 1

Quoting the documentation: "Presently our Simulation is one big monolithic scenario. So first let us split it into composable business processes, akin to the PageObject pattern with Selenium. This way, you’ll be able to easily reuse some parts and build complex behaviors without sacrificing maintenance." at gatling.io/Advanced Tutorial
Thus your there is no build-in mechanism for communication between scenarios (AFAIK). Recommendation is to structure your code that way that you can combine your calls to URIs subsequently. In your case (apart from implementation details) you should have something like this:
val auths = feed(credentials)
.feed(firstNames)
.feed(lastNames)
.feed(cards)
.feed(amounts)
.exec(http("send auth requests")
.post(...)
.check(...) // extract and store RESPONSE_ID to session
)
val caps = exec(http("send auth requests")
.post(...) // use of RESPONSE_ID from session
.check(...))
Then your scenario can look something like this:
val scn = scenario("auth with caps").exec(auths, caps) // rest omitted
Maybe even better way to structure your code is to use objects. See mentioned tutorial link.
More illustrative example (which compiles, but I didn't run it while domain is foo.com):
import io.gatling.core.Predef._
import io.gatling.http.Predef._
class ExampleSimulation extends Simulation {
import scala.util.Random
import scala.concurrent.duration._
val httpConf = http.baseURL(s"http://foo.com")
val emails = Iterator.continually(Map("email" -> (Random.alphanumeric.take(20).mkString + "#foo.com")))
val names = Iterator.continually(Map("name" -> Random.alphanumeric.take(20).mkString))
val getIdByEmail = feed(emails)
.exec(
http("Get By Email")
.get("/email/$email")
.check(
jsonPath("userId").saveAs("anId")
)
)
val getIdByName = feed(names)
.exec(
http("Get By Name")
.get("/name/$name")
.check(
jsonPath("userId").is(session =>
session("anId").as[String]
)
)
)
val scn = scenario("Get and check user id").exec(getIdByEmail, getIdByName).inject(constantUsersPerSec(5) during (5.minutes))
setUp(scn).protocols(httpConf)
}
Hope it is what you're looking for.