Pritam Banerjee Pritam Banerjee - 21 days ago 11
Scala Question

Why is this Gatling job not running sequentially?

What I am trying to do is:


  1. Make a GET call to get a list of
    id

  2. For all those ids make a series of another GET calls



Here is my code for that:

/**
* Created by pbane3 on 11/10/16.
*/

import io.gatling.core.Predef._
import io.gatling.http.Predef._
import scala.concurrent.duration._
import scala.concurrent.forkjoin.ThreadLocalRandom
import scala.collection.mutable
import scala.collection.Map


class RunWithMePerfTest extends Simulation {

var idList = List[String]()

var count = 0;

def idFeeder(idString:String):Unit = {
idList = idString.split(",").map(_.trim).toList;
println(idList)
}

def getRunId() : String = {
println(count)
var id = idList(count);
count = count+1;
return id;
}

object GetAllRunDetails {

val getAllRunDetails = exec(http("Get Run Ids")
.get("**/**")
.check(status in (200 to 209))
// .check(bodyString.saveAs("GetResponse"))
.check(jsonPath("$..id").ofType[String].findAll.transform(_.mkString(",")).saveAs("runId")))
.exec(
session => {
var getJson = session.get("GetResponse").asOption[String];
var runId = session.get("runId").asOption[String]
// println("Run ID === ")
// println(runId.get)
idFeeder(runId.get)
session
}
)
}

object GetRunIdDetails{

println("Length=" + idList.length)
val getRunIdDetails = repeat(idList.length) {

exec(http("Getting Run Details")
.get(s"****/***" + getRunId())
.check(status in (200 to 209))
.check(bodyString.saveAs("GetRunIdResponse"))
)
.exec(
session => {
var getResponse = session.get("GetRunIdResponse").asOption[String];
println("Response from Get" + getResponse.get)
session
}
)

}
}

val scn = scenario("All run details")
.exec(GetAllRunDetails.getAllRunDetails, GetRunIdDetails.getRunIdDetails)

setUp(scn.inject(atOnceUsers(1)));

}


But here why is
GetAllRunDetails.getAllRunDetails
not running before
GetRunIdDetails.getRunIdDetails
? That is my idList is never getting defined.

The error that I am getting is this:

Length=0
0
Exception in thread "main" java.lang.IndexOutOfBoundsException: 0
at scala.collection.LinearSeqOptimized$class.apply(LinearSeqOptimized.scala:65)
at scala.collection.immutable.List.apply(List.scala:84)
at nike.runwithme.performance.RunWithMePerfTest.getRunId(RunWithMePerfTest.scala:27)
at nike.runwithme.performance.RunWithMePerfTest$GetRunIdDetails$.<init>(RunWithMePerfTest.scala:57)
at nike.runwithme.performance.RunWithMePerfTest.GetRunIdDetails$lzycompute(RunWithMePerfTest.scala:51)
at nike.runwithme.performance.RunWithMePerfTest.GetRunIdDetails(RunWithMePerfTest.scala:51)
at nike.runwithme.performance.RunWithMePerfTest.<init>(RunWithMePerfTest.scala:73)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at java.lang.Class.newInstance(Class.java:442)
at io.gatling.app.Gatling$.io$gatling$app$Gatling$$$anonfun$1(Gatling.scala:41)
at io.gatling.app.Gatling$lambda$1.apply(Gatling.scala:41)
at io.gatling.app.Gatling$lambda$1.apply(Gatling.scala:41)
at io.gatling.app.Gatling.run(Gatling.scala:92)
at io.gatling.app.Gatling.runIfNecessary(Gatling.scala:75)
at io.gatling.app.Gatling.start(Gatling.scala:65)
at io.gatling.app.Gatling$.start(Gatling.scala:57)
at io.gatling.app.Gatling$.fromArgs(Gatling.scala:49)
at io.gatling.app.Gatling$.main(Gatling.scala:43)
at io.gatling.app.Gatling.main(Gatling.scala)

Answer

So here is the answer that worked for me. Almost same code, but added a session to the second scenario. Makes sense, because everything is added to the session:

/**
  * Created by pbane3 on 11/10/16.
  *
  * The First test gets the Run Id's
  *
  * Then it creates a a List of all the RunIDs
  *
  * After that loops through each of the RunIDs
  * and makes a GET call for each of them
  */

import io.gatling.core.Predef._
import io.gatling.http.Predef._
import scala.concurrent.duration._
import scala.concurrent.forkjoin.ThreadLocalRandom
import scala.collection.mutable
import scala.collection.Map
import java.io.File
import java.io.PrintWriter



class RunWithMePerfTest extends Simulation {

  //this is used to store the list of the runIds
  var idList  = List[String]()

  var count = 0;

  //used to build the list and feed to the session
  def idFeeder(idString:String):Unit = {
    idList = idString.split(",").map(_.trim).toList;
    println(idList)
  }

  //used to access the list and feed to the session
  def getRunId() : String = {
     println(count)
     var id = idList(count);
     count = count+1;
     return id;
  }

  //makes the initial call to get all the run IDs
  object GetAllRunDetails {
    println("I come in scn1")
    val getAllRunDetails = exec(http("Get Run Ids")
      .get("https://someUrl")
      .check(status in (200 to 209))
      // .check(bodyString.saveAs("GetResponse"))
      .check(jsonPath("$..id").ofType[String].findAll.transform(_.mkString(",")).saveAs("runId")))
      .exec(
        session => {
          var getJson = session.get("GetResponse").asOption[String];
          var runId = session.get("runId").asOption[String]

          idFeeder(runId.get)
          session
        }
      )
  }

  //makes one get call for each of the run ids obtained from the last get call
  object GetRunIdDetails{
    val getRunIdDetails =  repeat(session=>idList.length) {
      exec(http("Getting Run Details")
        .get(session => (s"https://someUrl" + getRunId()))
        .check(status in (200 to 209))
        .check(bodyString.saveAs("GetRunIdResponse"))
      )
        .exec(
          session => {
            var getResponse = session.get("GetRunIdResponse").asOption[String];
            println("Response from Get:")
            println(getResponse.get)
            session
          }
        )
    }
  }

  val scn1 = scenario("All run details")
    .exec(GetAllRunDetails.getAllRunDetails)

  val scn2 = scenario("All run ID Details")
    .exec(GetRunIdDetails.getRunIdDetails)


  setUp(scn1.inject(atOnceUsers(1)),scn2.inject(nothingFor(10 seconds),atOnceUsers(1)));

}