Parameterized simulation in Gatling load tests

Question

I want to be able to pass parameters to a Gatling Simulation. I have tried this, however it is failing. (The issue seems to be due to inner class)

object PerfTestManager extends App {
    run("trymain", 10, 2, 3);
    def run(dcName: String, minutes: Int, threads: Int, maxThreads: Int) = {
         class BasicSimul extends Simulation {
            val scn = scenario("a").feed(QueryFeeder.myfeeder)
                    .exec(http("test").get(s => SolrEnv.getPath(s("params").validate[String].get)));
            private val hostport = SolrEnv.hostport

            val httpConf = http.baseURL(hostport)
                        .acceptHeader("text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8")
                        .acceptEncodingHeader("gzip, deflate")
                        .acceptLanguageHeader("en-US,en;q=0.5")
                        .userAgentHeader("Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:16.0) Gecko/20100101 Firefox/16.0");
            setUp(scn.inject(atOnceUsers(threads)).protocols(httpConf))

        }

        val simClass = classOf[BasicSimulation].getName
        val props = new GatlingPropertiesBuilder
        props.dataDirectory(Paths2.dataDirectory.toString)
        props.resultsDirectory(Paths2.resultsDirectory.toString)
        props.bodiesDirectory(Paths2.bodiesDirectory.toString)
        props.binariesDirectory(Paths2.mavenBinariesDirectory.toString)

        props.simulationClass(simClass)
        props.runDescription("runonce")
        props.outputDirectoryBaseName("0")
        Gatling.fromMap(props.build) // <-- failing line
    }
}

My intention is to eventually run a webservice, which will be used to schedule and parameterize the Simulations from a UI. While I have a some alternatives which I can try, something closer to the above code seems the easiest to maintain. Above code fails, as gatling is unable to create an instance of BasicSimul

Caused by: java.lang.NoSuchMethodException: computerdatabase.PerfTestManager$BasicSimul$1.<init>()
    at java.lang.Class.getConstructor0(Class.java:3082)
    at java.lang.Class.newInstance(Class.java:412)

I also tried to pass parameters to BasicSimulation, however, the framework requires a default constructor so that was not successful either.

My alternative will be to declare the following in an object

val q = new Queue

The scheduling webservice will enqueue a new TestConfig based on the parameters, and BasicSimulation will dequeue() to get its TestConfig. Synchronized constructs can be used to avoid race conditions.

user666 user666 · Accepted Answer · 2017-03-24T16:11:16

I think you can achieve the above behavior in a better way by creating a simple Scala class for doing this .Basically you can create an object

object Configuration{
 val file = getClass.getResource("data/config.properties").getFile()
 val prop = new Properties()
 prop.load(new FileInputStream(file))
 ENV =prop.getProperty("env");
}

Now in your Simulation class

class TestSimulation extends Simulation {
   val ALL_STOP_STATUS = Configuration.ENV;
 }

Similarly specialize it even more to use path variables

Parameterized simulation in Gatling load tests

1 Answers