Stress testing REST APIs is essential for your company to get a handle on how well your APIs are performing under demanding traffic situations. Unlike other load tests, a stress test eliminates the need for configuring complex tools.

Load tests are still an essential part of understanding how your company’s website and applications perform, but it’s unnecessary to configure jMeter or Locust just to look at this piece of the picture.

What is RESTful API (REST API) testing?

Testing REST API’s look at how well the API performs, not the database or application server infrastructure. RESTful APIs handle communication between different applications, thus making the load test about ensuring the communication interface between different applications continues to successfully queue and fulfill data exchange requests when multiple interactions stack up.

Scope of REST API stress test

Sometimes it makes sense to run a single request rather than running continuous calls to gauge performance. However, in the case of the REST API testing tool, the single request test is not recommended. That test will give you data on how well an individual request works at a given time as opposed to observing the API and infrastructure under demanding use cases, which is what a stress test should be looking at. The idea behind the stress test is to generate a substantial number of HTTP requests at once, and see if the REST execution continues to work.

REST API stress test automation

While it’s possible to perform a stress test on RESTful APIs by simply gathering a group of people together using multiple devices to mass-generate HTTP requests, it’s not often practical. When designing a RESTful API stress test, your development team will likely single out a specific page request that makes a REST call for the purpose of the test. Automating this process can save your business time and energy.

Your development team can utilize a browser automation program or HTTP request tool to simulate a large number of requests for the test. A browser automation program like Selenium records user actions that can be exported and reused as a script on multiple devices simultaneously, which simulates virtual users repeatedly calling a RESTful API request. Alternatively, try Google Chrome plug-in RESTful Stress to stress test an API by batch invoking HTTP requests.

Multiple systems for stress testing RESTful API

Running the test on a single device may not generate enough HTTP requests to push the API as far as it needs to go. A browser action recording program will work on any platform, but is limited by how quickly the computer can simulate the test (which can be offset by things like page load times and database calls). Since the stress test is not examining these parts of the application infrastructure, those bottlenecks can hinder the actual test. You can work around these limitations by running the test on multiple computers at once.

Bringing It Together, Testing in Development

Looking at a hypothetical ASP.NET application for the test, the development team may opt to create a large testing load by using multiple computers running browser recording software. Running these tests can also be a helpful measure of how well the API performs under heavy traffic loads by utilizing the testing or development servers instead of the production servers. That’s because the test is looking at whether the API is able to keep up with high volume requests.

If your business is looking to get a better understanding of how its website and web applications perform through techniques like load testing, contact the experts at Apica today!