What is Selenium Grid ?

Selenium Grid allows you to:

• scale by distributing tests on several machines ( parallel execution )
• Manage multiple environments from a central point, making it easy to run the tests against a vast combination of browsers / OS.
• Minimize the maintenance time for the grid by allowing you to implement custom hooks to leverage virtual infrastructure for instance.

Step 1: Start the hub

• The Hub is the central point that will receive all the test request and distribute them the the right nodes.
• Open a command prompt and navigate to the directory where you copied the selenium-server-standalone file. Type the following command:
• java -jar selenium-server-standalone-2.14.0.jar -role hub
• The hub will automatically start-up using port 4444 by default. To change the default port, you can add the optional parameter -port when you run the command. You can view the status of the hub by opening a browser window and navigating to: http://localhost:4444/grid/console

Step 2: Start the nodes

• Regardless on whether you want to run a grid with new WebDriver functionality, or a grid with Selenium 1 RC functionality, or both at the same time, you use the same selenium-server-standalone jar file to start the nodes.
• java -jar selenium-server-standalone-2.14.0.jar -role node  -hub http://localhost:4444/grid/register
• Note: The port defaults to 5555 if not specified whenever the "-role" option is provided and is not hub.
• For backwards compatibility "wd" and "rc" roles are still a valid subset of the "node" role. But those roles limit the types of remote connections to their corresponding API, while "node" allows both RC and WebDriver remote connections.
• For WebDriver nodes, you will need to use the RemoteWebDriver and the DesiredCapabilities object to define which browser, version and platform you wish to use. Create the target browser capabilities you want to run the tests against:
• DesiredCapabilities capability = DesiredCapabilities.firefox();
• Pass that into the RemoteWebDriver object:
• WebDriver driver = new RemoteWebDriver(new URL("http://localhost:4444/wd/hub"), capability);