Ramping VUs in k6

When creating a load test, it is sometimes desirable to control how the rate of requests are scaled over time. k6 provides this behavior through the ramping-vus executor, which allows gradual scaling of virtual users over a specified duration. This enables realistic simulations of user traffic patterns as expected in real-world use cases. In this brief post, we will outline the basics of using this feature in k6. Example Script of Ramping VUs The following k6Read More →

Large-Scale and Distributed Load Testing with k6

Owing to an efficient design and low overhead, k6 tests have an inherent ability to scale well. Compared to other testing frameworks, users of k6 can often expect less resource utilization. As described in the official documentation, k6 tests scale well on single instances, lending to reduced requirements when performing distributed load testing. In this brief article, we will show you how cloud-based platforms like RedLine13 allow you scale your k6 tests across multiple load generatorRead More →

The k6 Browser Recorder

When creating your test plans in k6, it is a common practice to write the script with a bottom-up approach. In other words, each request is explicitly coded in sequence with a series of http request methods wrapped in flow control. While this method provides the ultimate means of control, tests can also be built using the k6 Browser Recorder. With this alternative, a browser plugin allows you to record a series of interactions with aRead More →

Setting k6 Environment Variables

Building on the concept of extensibility, k6 has the ability to read variables set in the local environment and apply them to test scripts.  Reusable scripts often only require minor changes to be used in different contexts, and k6 environment variables provide this.  In addition, there are some k6 extensions that depend on environment variables to set their configuration.  In this post, we will show you how to set k6 environment variables both in your localRead More →

Tags and Thresholds in k6

In this brief post, we will cover how to add individual requests to groups using the tags feature of k6. This feature can be used to label thresholds for reporting on grouped requests. By separating result metrics generated by your k6 test, it can become possible to isolate the performance of individual or related requests. Suppose for a given test we have identified a performance issue; however the test is made up of several different requests.Read More →

Importing User Modules in k6

In previous posts we have commented on extensibility as a hallmark of the k6 architecture. While there are a wide variety of official modules you can easily import into your k6 tests, it is also possible to import custom JavaScript code. In this brief post we will show you how to easily import code from your own modules. This can potentially accelerate your development efforts by reusing these modules across multiple tests, while at the sameRead More →

k6 Error Handling

When testing at scale, it is inevitable that at some point your load test will encounter error states. It may even be a condition itself that is tested. Therefore, it is essential that we have a capability to capture and analyze error information. In this brief article, we will detail how to intercept and log errors in your k6 load tests. Intercepting and Logging Errors Ideally, we would like to save errors to a retrievable logRead More →

Common Tasks in k6

When writing your k6 test scripts, there are certain common tasks that are recurrently encountered. In this post, we will discuss examples on how to accomplish several of these common tasks. Most of these examples are illustrated in the official k6 documentation pages. Entering Data into Web Forms User submission forms are a common target test endpoint. Tests such as these must be designed in a way that form fields are identified and mapped to usefulRead More →

Functional Testing with k6

In previous posts we have covered the ability to use k6 for scalable load testing, however k6 is also a suitable framework for creating functional tests. In this brief post, we will show you how to get started with using k6 as a functional testing tool. Assertions in k6 There are two basic ways to write assertions in k6. One is using the built-in check and group functions. Perhaps a better alternative is to use theRead More →

The k6 Graphical Test Builder

Most examples that illustrate how to create a k6 load test center around using a bottom-up approach with code. This is in contrast with frameworks such as JMeter where it is typical for tests to be created visually. However, there is a utility by Grafana Labs for creating k6 load tests with a GUI. In this post, we will show you how to use the graphical Test Builder to create k6 load tests. The Graphical k6Read More →