how to run gatling scenarios sequentially and not concurrently?

Question

I have created a simple gatling maven application to test performance, verify API rate limit(so if sent requests more than its rate limit it should fail) . In order to run each api as an independent operation and not concurrently, I have created separate simulation classes for each API call to test. In order to run them in a sequential order I have enabled runMultipleSimulations . Followed eg configuration from: galting doc: https://gatling.io/docs/3.0/extensions/maven_plugin/

But I don't think they are running in sequential order and one scenario that I see from logs, is mostly showing failed user requests with 500 internal server errors, neither I see all test scenarios in logs . Do I need anything else beyond including this dependency ? Here is my pom.xml :

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>gatling-test</groupId>
    <artifactId>gatling-test</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <gatling-plugin.version>3.0.1</gatling-plugin.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>io.gatling.highcharts</groupId>
            <artifactId>gatling-charts-highcharts</artifactId>
            <version>3.1.2</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <testSourceDirectory>src/test/scala</testSourceDirectory>
        <plugins>
            <plugin>
                <groupId>io.gatling</groupId>
                <artifactId>gatling-maven-plugin</artifactId>
                <version>${gatling-plugin.version}</version>

                <configuration>
                    <runMultipleSimulations>true</runMultipleSimulations>
                </configuration>

                <executions>
                    <execution>
                        <goals>
                            <goal>test</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

</project>

Eg: of a scenario file :

class DeleteAPISimulation extends Simulation {
  var test = ""

  val preScenario = scenario(" DELETE API PRE-SCENARIO")
    .exec(CreateResource())
    .exec(session => {
      test = session("resourceId").as[String].trim
      println("%%%%%%%%%%% resource ID =====>>>>>>>>>> " + test)
      session}
    )
  val deleteResourceScenario = scenario("DELETE API TEST SCENARIO")
    // Set it here
    .exec(_.set("resourceId", test))
    .exec(DeleteResource())

  setUp(
    preScenario.inject(atOnceUsers(1)),
    deleteResourceScenario.inject(rampUsers(520) during(60))
  )

}

Actions class has DSL http requests implementations for APIs. Eg:

object Actions{

def DeleteResource():HttpRequestBuilder = {
  http("DELETE_RESOURCE_OPERATION")
    .delete(Host+ "/items/${resourceId}")
    .header("Authorization", "Bearer "+ Token)
    .check(status.is(200))
}
.
.
//so on
// similar api method requests
.
}

Below is how my project structure looks and action class as well as scenario simulation classes resides under src/test/scala:

gatlingtest 
  - src
     - test 
       - resources
       - scala
           - Actions
           - CreateAPISimulation
           - GetAPISimulation
           - DeleteAPISimulation

Stéphane LANDELLE Stéphane LANDELLE · Accepted Answer · 2020-05-02T12:00:13

As of Gatling 3.3, there's no real way to run scenarios sequentially. The only solution is to start the other scenarios after some delay, see nothingFor.

Sequential scenarios will be introduced in Gatling 3.4 (released in September 2020).

how to run gatling scenarios sequentially and not concurrently?

1 Answers