Simulating heavy traffic

Gatling and Gatling Enterprise are load testing solutions for web applications. You can simulate up to millions of virtual users navigating on your application. Load testing helps to anticipate slowdowns and crashes of applications under heavy traffic.

Why load testing is critical for your business to handle heavy traffic

Traffic spikes often happen in critical situations for your business. Go-lives of your applications, seasonal events, national TV appearances, or tickets sales opening can bring a lot of unexpected but wanted visitors.

By simulating complex users’ behaviors or peaks of traffic, you can analyze your application’s performances precisely  and identify its bottlenecks.
It can be a feature, a microservice, your infrastructure or even your architecture. Load testing is here to help you find the culprit and adjust your resources accordingly.

Load testing can have a huge impact on business. Cost, image, performance and even turnover… Your website is your face to the world and it sends signals to the customers.

Why load testing matters for your business

How does load testing work?

There are numerous tests you can do to check your website’s health. Load tests are focused around heavy traffic simulation.

A “load generator” will create virtual users by sending requests (HTTP or any other web protocol) to a server . These requests are generated according to a workflow defined in a simulation to reproduce a real user’s behavior. Thus, the number of requests will define the number of users you want to see.

Since virtual users are made of requests, Gatling and Gatling Enterprise are agnostic solutions. It means that you can test all your applications, whatever the underlying technologies, as long as they are based on web protocols.

Then, the load generator collects the response times of all the requests. If you are using Gatling, it will generates an HTML report, including data and charts about your test.
If you are using Gatling Enterprise, your load generators send all the metrics collected to a database. You can then watch your reports in real time in a centralized web interface and compare your test’s results with the history of all your load tests.

How to use Gatling and Gatling Enterprise?

Load testing is about experimenting and investigating for heavy traffic issues. You need first to have a good knowledge of your users’ behaviors, to craft your simulations. Gatling’s recorder allows users to bootstrap simulation’s code and then test their application or only parts of it, to understand where are the bottlenecks.

You can use various injection profiles (how your virtual users are injected in your system) and different kinds of load tests to investigate your application:

  • Capacity test: increase step by step your users’ arrival rate until your system crashes, to find out how many concurrent users your system can handle
  • Stress test: simulate a peak of traffic with a high number of virtual users arriving in your system within the same time window, to validate your application’s performances according to your business strategy
  • Soak test: run a load test over several hours or days to measure the long-term impacts of traffic on your website (e.g. memory leaks)

At the end of your tests, you can analyze your reports and iterate by changing one or several parameters, to investigate further your performance issues and ultimately solve them.

Open source or for business, Gatling provides a solution adapted to each type of project. It’s also compatible with numerous third parties and technical environments. In the end, it is built to be easy to use and flexible. That’s why it’s used by a big community all over the world. A community you can always poke for help.