I had to write a short article about Selenium Grid in my first work week in the marketing department of an IT company. I asked a colleague, who is a test automation engineer, what Selenium Grid is. She looked at me surprised. It was as if I were asking her what she needed a cup for when making coffee. From this reaction, we can conclude that it is difficult to do without this solution in automated testing. What is the secret of Selenium Grid and why does it make sense to pay for using an open-source solution? Read this article to find out.

Parallel testing solution

The history of Selenium Suite, which includes Selenium Grid, began in 2004. ThoughtWorks employee Jason Huggins decided to make it simpler to test internal software and invented a special mode for this. Later, he showed it to his colleagues, and they were delighted. It was decided that this solution should be available to everyone.

Selenium Grid is an open-source environment that distributes tests across numerous machines. The solution enables parallel testing against a range of browsers and operating systems. Thus, this tool greatly speeds up the testing process and ensures maximum test coverage.

So let’s understand how Selenium Grid operates.

The basis of Selenium Grid

Selenium Grid is based on two components. The first component is the hub. It’s the only one in the grid. The hub distributes tests among the available nodes.

Node is the second component of Selenium Grid. There are several nodes in the grid. They are virtual or real machines that are connected to the hub. The more nodes we have, the more parallel threads we can run, and the sooner we will complete all the tests. To understand it better, let’s explain everything using the example of a food delivery application.

Imagine that we are developing such an application. Customers of food delivery services are a fairly wide audience in terms of socio-demographic characteristics, so it hardly makes sense to focus on one operating system and one browser. We should do our best to make our application available to clients with any of the possible combinations of browsers and operating systems.

Thus, each of our nodes is a machine with a specific operating system and a set of browsers with specific versions. So, in the first node we have Windows operating system, the second is Mac, the third is Linux, the fourth is Android, the fifth is iOS, and the sixth is windows again but with a set of older browser versions, etc.

The test execution time can be calculated using the following formula:

Total test execution time = Number of tests * Average time required to complete a test / Number of nodes

Let’s imagine that we need to test 100 tests, testing one test takes 45 seconds, and we have set up 15 nodes in Selenium. Plug these numbers into the formula above:

100*45/15=360 seconds

It turns out that the execution of 100 tests will take 5 minutes. Without Selenium Grid, the tests would have taken 1 hour and 15 minutes.

Selenium Grid strength overview

We know from the previous section that Selenium Grid reduces the time spent on testing many times over. The solution provides high test coverage because of its ability to test software on a list of browsers, operating systems, and combinations thereof. Open-source is another item on the list of solution advantages, but not the last. See the strengths of Selenium Grid, in addition to everything that we have listed above.

A wide range of supported languages

Python, Java, JavaScript, Ruby, C#, and Perl are among the programming languages ​supported by Selenium Grid.

Companies always pay attention to the support of languages when they choose a new solution. Is it impossible to use the programming language that is used on the current project? Okay, the choice will likely be in favor of another solution.

Ability to integrate with reporting frameworks

Selenium Grid integrates with numerous third-party frameworks that help collect, process, and visualize reports.

Effective testing needs progress tracking and test monitoring. Usually, these functions are performed by reporting. Through reporting you compare actual results of product testing with expected ones, see trends, and identify root causes of issues. However, creating reports manually is inconvenient and very time-consuming.

Incorporation into CI/CD pipeline

CI/CD pipeline (continuous integration and continuous development) is development stages that a product or its version go through before entering the market. The ability to integrate Selenium Grid with CI/CD tools helps QA and development teams to get the most out of test automation.

Code reuse

Selenium Grid has a number of features that let you avoid code duplication. Code regrouping, Page Object Model, and code refactoring ensure maximum code reuse.

Community access

Selenium has its own community that brings together developers and testers from all over the world. You can ask your question and get a quick reply. In addition, there are several Selenium official channels and many unofficial forums.

How to get the most out of Selenium Grid

Selenium Grid looks like the perfect tool, but let’s be objective. Complicated setup and support are among the biggest weaknesses of the environment. To customize Selenium Grid for yourself, you need your team to have years of experience with it. In addition, the speed and scope of testing are limited by the number of available nodes.

These shortcomings are quite significant, so many commercial solutions simplify the use of Selenium Grid. Zebrunner Selenium Grid is a such solution, where you only reach the benefits of Selenium Grid. You get an environment customized to your needs and you can run tests right away. The speed and volume of testing are also unlimited, you can run 1000 or more threads at the same time and get fast results.

To know more about Selenium Grid and why you should choose a paid Selenium Grid environment read the article.