Selenium Grid Hub JSON Configuration

Overview

In this tutorial, we will learn how to customize Selenium Grid Hub with JSON Configuration file. We can customize Selenium Grid with JSON configuration file. JSON stands for JavaScript Object Notation. It is a light-weight data exchange format to exchange data between the client and the server. JSON is also human readable file format and used for configuration files.

Selenium Grid Hub Configuration

Create a JSON file with Hub configuration. We can specify and customize many configuration parameters in this file.

Sample Hub configuration file

We have changed the Grid listening port to 5555 and timeouts. Place the file in the Selenium jar directory. We can just pass the filename in the Grid start command in the next section.

{
 "port": 5555,
 "newSessionWaitTimeout": 12000,
 "servlets" : [],
 "withoutServlets": [],
 "custom": {},
 "capabilityMatcher": "org.openqa.grid.internal.utils.
DefaultCapabilityMatcher",
 "registry": "org.openqa.grid.internal.DefaultGridRegistry",
 "throwOnCapabilityNotPresent": true,
 "cleanUpCycle": 5000,
 "role": "hub",
 "debug": true,
 "browserTimeout": 120,
 "timeout": 120
}

Start the Hub with Config File

Now, we can start the Grid with the JSON configuration file using the below command. The command line switch is -hubConfig followed by the JSON configuration file name. The JSON file should define the hub properties.

\>java -jar <selenium-server-standalone-version.jar> -role hub -hubConfig hubConfig.json