Understanding Gatling: A Comprehensive Guide for Beginners

Cheat Sheet for Understanding the Load Testing Tool Gatling


If you’re considering dipping your toes into the world of performance testing, Gatling may be just the open-source tool you need. This comprehensive guide will give you an overview one of the powerful Gatling load testing tools, as well as its major features and advantages.




Introduction to the Performance Testing Tool Gatling?

Gatling is an open-source load-testing tool for web applications and websites. It is designed to simulate large numbers of users as they interact with application components, such as databases, services and pages. Gatling supports many protocols such as HTTP/S, FTP, IMAP, LDAP and more. It comes with a powerful assertion library that allows the user to test their responses in various ways. Reports are generated by collecting metrics at various levels ranging from individual requests to simulation-level results over a period of time.


What Types of Performance Tests Can You Run With Gatling?

Gatling is designed to make it easy to test the performance of your web application under load. It can be used to perform a variety of different types of tests, including soak tests, spike tests and stress tests. Soak tests are useful for measuring the performance of an application over long periods of time, while spike tests determine how quickly an application recovers from sudden increases in traffic. Stress tests are useful for testing an applications’s maximum capacity by simulating a large number of users hitting the application at once. This can help you understand where the bottlenecks in an application lie and how best to optimize its performance.

How Does the Load Testing Tool Accomplish Its Tasks?

Gatling uses a combination of hardware and software to simulate a large number of virtual users hitting a web application at once. Specifically, it uses multiple computer nodes running the Gatling tool in parallel to generate traffic that can be scaled up or down according to the test needs. In addition, Gatling provides numerous options for creating scenarios and configuring how requests are made, making it straightforward to customize how different scenarios are tested. It also offers multiple metrics for measuring performance, as well as powerful reporting capabilities.


What Type of Reports Does the Load Test Tool Generate?

Gatling provides numerous types of pre-configured reports that can be generated to evaluate the performance of distributed tests. For example, there are Request and Response reports which show how a server responds to requests over time and whether or not any errors occurred in the process. It is also possible to generate Latency and Throughput reports that provide insights into the server performance at different points throughout the test. Statistics such as number of failures per second, percentile metrics, and request throughput can all be included in these reports.

How Do You Get Started with Load Tests?

Getting started with Gatling is relatively straightforward. The open-source nature of the project allows users to simply download the software from the official website and then begin testing performance. If you prefer, there is also a commercial version available that includes additional features such as detailed analytics and support from Gatling engineers. Before running any tests be sure to familiarise yourself with the basics of how Gatling works so that you can get the most out of it. This includes setting up the appropriate test scenarios, configuring any desired assertions, and establishing resources to generate your own reports.


Gatling CheatSheet:

Check our cheatsheet to learn the usage of commands and save time.



Install Gatling

$ brew install gatling
Start a new simulation

$ gatling.sh -on <simulation name>

Define the scenario

val scn = scenario(“<Scenario name>”).exec(<HTTP request>)

Define the load profile

setUp(scn.inject(<load profile>).protocols(<HTTP protocol>))

Run the simulation

$ gatling.sh -sf <simulation directory> -s <simulation name>

View the results

$ gatling.sh -ro <simulation directory>

Command-line options

-on : name of the simulation

-sf : path to the simulation directory

-s : name of the simulation class

-ro : path to the results directory

Gatling DSL

.exec(http(“<request name>”).<http method>(“<url>”).headers(<headers>).queryParam(<query params>).formParam(<form params>))

Gatling Load Profiles

rampUsers(<users>) over (<duration>)

constantUsersPerSec(<users>) during (<duration>)

Gatling Reports





Common Questions on Gatling Usage

1. What is Gatling?

Gatling is a load testing tool that allows you to test the performance and responsiveness of your application under various scenarios. It is primarily used for HTTP load testing.

2. Why do I need to use Gatling?

Gatling helps you ensure that your application can handle high loads and perform well under stress conditions. It allows you to simulate thousands of virtual users and monitor the response times and other performance metrics of your application.

3. How can I install Gatling?

You can find the latest version of Gatling on the official website. Download the appropriate archive, extract it, and you are ready to use Gatling.

4. How do I create a Gatling test scenario?

Gatling tests are written in Scala programming language. You can create a test scenario by writing code that defines the HTTP requests, pauses, checks/assertions, and other actions you want to simulate. Gatling provides a comprehensive documentation and examples to help you get started.

5. How can I check the response status of HTTP requests in Gatling?

You can use the Gatling DSL to define checks and assertions on the response status codes. For example, you can verify that a request returns a 200 status code or any other desired code.

6. Can Gatling simulate different types of HTTP requests?

Yes, Gatling supports various types of HTTP requests such as GET, POST, PUT, DELETE, etc. You can easily specify the desired HTTP method in your test scenario.

7. How many virtual users can Gatling simulate?

Gatling can simulate thousands of virtual users depending on the hardware and resources available. It is designed to handle high loads and can scale up to meet your performance testing needs.

8. How do I provide test data for my Gatling simulation?

Gatling provides a feature called feeders that allow you to provide test data from various sources such as CSV files, databases, or even generate it programmatically. You can use feeders to dynamically inject data into your test scenarios.

9. Is there a cheat sheet available for Gatling?

Yes, there is a Gatling cheat sheet available that provides a quick reference guide for common Gatling commands and syntax. It can be very useful for both beginners and experienced users.