Gatling Load Testing — Overview
Warning
This course is LLM generated, there might be mistakes and inaccuracies in it!
What is Gatling?
Gatling is an open-source load testing framework built on Akka and Netty. It is designed to simulate thousands of concurrent users hitting your application and producing detailed HTML reports.
Key traits: - Code-first (simulations are real code, not XML/YAML) - Supports Java, Kotlin, and Scala DSLs - Async, non-blocking engine — lightweight per virtual user - Built-in HTML reports with percentile breakdowns - Easy CI/CD integration
When to use Gatling
| Use case | Good fit? |
|---|---|
| REST API load testing | Yes |
| WebSocket / SSE testing | Yes |
| JMS / gRPC (via plugins) | Yes |
| Browser-level UI testing | No (use k6/Playwright) |
| Unit / integration tests | No |
Key terms
| Term | Meaning |
|---|---|
| Simulation | The top-level class that wires everything together |
| Scenario | A sequence of steps a virtual user executes |
| Virtual user | A simulated user running a scenario |
| Injection profile | How virtual users are ramped up over time |
| Feeder | A data source that provides per-user test data |
| Check | An assertion on the HTTP response |
| Session | Per-user key/value store available throughout a scenario |
Course structure
| Module | Topic |
|---|---|
| 01 — Setup | Maven / Gradle project for Java & Kotlin |
| 02 — Core concepts | Simulation anatomy |
| 03 — HTTP protocol | Base URL, headers, auth |
| 04 — Scenarios | exec, pause, loops, conditionals |
| 05 — Feeders | CSV, JSON, programmatic |
| 06 — Checks | Status, body, headers, jsonPath |
| 07 — Injection profiles | Open / closed workload models |
| 08 — Session | Reading and writing session variables |
| 09 — Reports | Understanding the HTML report |
| 10 — Best practices | CI/CD, tips, common pitfalls |
Gatling editions
| Edition | Notes |
|---|---|
| Gatling OSS | Free, everything in this course |
| Gatling Enterprise | Cloud + on-prem orchestration, advanced metrics |
Info
All examples in this course use Gatling OSS 3.15+ with the Java/Kotlin DSL.