Gatling

When to Use

• High Throughput: When you need to simulate 10k+ users from a single laptop.
• Complex Scenarios: The DSL (Domain Specific Language) allows describing very complex user journeys.
• JVM Shops: If your team uses Java/Scala/Kotlin.

Quick Start (Java)

import static io.gatling.javaapi.core.CoreDsl.*;
import static io.gatling.javaapi.http.HttpDsl.*;

public class BasicSimulation extends Simulation {

  HttpProtocolBuilder httpProtocol = http
    .baseUrl("http://computer-database.gatling.io")
    .acceptHeader("application/json");

  ScenarioBuilder scn = scenario("BasicSimulation")
    .exec(http("request_1").get("/computers"));

  {
    setUp(
      scn.injectOpen(atOnceUsers(10))
    ).protocols(httpProtocol);
  }
}

Core Concepts

Simulation

Feeders

Best Practices (2025)

• Use the Java/Kotlin DSL: Scala was the default, but Java/Kotlin SDKs are now first-class and easier for most teams.
• Record User Journeys: Use the Gatling Recorder (proxy) to capture browser interactions, then clean up the code.

• Don't ignore reports: Gatling generates beautiful HTML reports at the end. Open

  index.html

  to see the response time distribution graphs.

References

• Gatling Documentation