YARN is a completely rewritten architecture of a Hadoop cluster. Once you are done with your development of the YARN application framework, the next step is to create your own custom application that you wish to run on YARN across a Hadoop cluster. Let's write a small application. In my example code, I have provided two applications:

• MyApplication.java: This prints Hello World
• MyApplication2.java: This calculates the value of PI to the 1,000^th level

These simple applications would be run on the YARN environment through the client we have created. Let's look at how you can build a YARN application.