Gatling exec outside scenario scope - POST requests are not called

Question

I am trying to write gatling performance test where I am using the before and after blocks of the Gatling Simulation to make one-time HTTP post requests against the service.

 class MyTest extends Simulation {
      
      // Some code here
      // and definitions
      
      val myScenario = scenario("Vary number of ...")
        .exec(PublishMessageRoundRobin(pConfigTest, testTitle + "-" + numX, numY))
    
      // extract the nodes  
      val nodes : Array[String]  = endpoints.split(endpointDelimiter)  
      
      //
      // create consumers with desired configurations at endpoint prior to scenario run
      // then start them
      //
      before {
          var endpoint = ""
                
          //
          // TODO: based on run parameter, decide if we should pre-run producers
          // 
          for( elt <- 1 to numX ) {
            endpoint = "http://" + nodes(elt-1) + cEndpoint + setConfig      
            CallSet( myobj, endpoint )
            endpoint = "http://" + nodes(elt-1) + cEndpoint + start  
            CallStart( myobj, endpoint )        
          }
      }
      
      if (testMode == "debug") {
        setUp(
          myScenario.inject(
            atOnceUsers(1)
          )
        ).protocols(httpConf)    
      } else if (testMode == "open") {
        setUp(
          myScenario.inject(       
            rampConcurrentUsers(20) to (200) during (durationInMinutes minutes),
          )
        ).protocols(httpConf)
      }
       
       // stop all consumers
       after {
           var endpoint = ""
           for( elt <- 1 to numX ) {
               endpoint = "http://" + nodes(elt-1) + cEndpoint + stop  
               CallStop(myobj, endpoint)
           }
       }
    
    }

CallStart and CallStop and CallSet are not making POST request for some reason. The only POST request called is the one defined within the scenario PublishMessageRoundRobin which calls exec and creates post against endpoint.

they are defined very similar way here is one of them

def CallStop(consumerConfig : ConsumerConfig, stopEndpoint : String ) = { 
      
      val jsonBody = consumerConfig.asJson
      val valuedJsonBody = Printer.noSpaces.copy(dropNullValues = true).print(jsonBody)
      println(valuedJsonBody)        
      println("stopEndpoint-" + stopEndpoint) 

      exec(http("StopConsumer-" + stopEndpoint)    
      .post(stopEndpoint)    
      .header(HttpHeaderNames.ContentType, HttpHeaderValues.ApplicationJson)
      .body(StringBody(valuedJsonBody))
      .check(status.is(200))
      .check(bodyString.saveAs("serverResponse"))
      )    
    .exec { session =>
      println("server_response: " + session("serverResponse").as[String])
      session
    }
  }

I see the println statements above but there is no POST request. Can someone help explain what is going on?

EDIT I am new to Gatling and Scala so I am not sure how to debug or have breakpoints. It seems that it fails silently which is concerning to me.

looks like from here gatling.io/docs/3.2/general/simulation_structure/… under Hooks section - can't use Gatling DSL — Saher Ahwal
it silently fails - which is big problem - no warning - no error / nothing... it just ignores DSL — Saher Ahwal

Saher Ahwal Saher Ahwal · Accepted Answer · 2020-08-15T01:46:16

Based on this - Gatling DSL doesn't work inside hooks. I wish there was a warning or something to not waste time on that.

I had to perform the actual POST request without using Gatling DSL as below.

 def CallStop(consumerConfig : ConsumerConfig, stopEndpoint : String ) = { 
          
          val jsonBody = consumerConfig.asJson
          val valuedJsonBody = Printer.noSpaces.copy(dropNullValues = true).print(jsonBody)
          println(valuedJsonBody)        
          println("stopEndpoint:" + stopEndpoint) 
    
          val post = new HttpPost(stopEndpoint)
          post.setHeader("Content-type", "application/json")
          post.setEntity(new StringEntity(valuedJsonBody))
          // send the post request
          val client = new DefaultHttpClient
          val response = client.execute(post)
    
          println("Response:" + response)
      }

Gatling exec outside scenario scope - POST requests are not called

1 Answers