YARN is a Java framework that is packaged with the Hadoop bundle. YARN provides resource management, as well as easy integration of data processing or accessing algorithms for data stored in Hadoop HDFS. Apache Storm, Giraph, and HAMA are few examples of the data processing algorithms that use YARN for resource management. A detailed integration of such technologies is covered in Chapter 12, Real-time Data Analytics Using YARN.
The Hadoop-YARN API is defined in the
org.apache.hadoop.yarn.api package. While writing your own YARN applications, you will use some of the classes from the YARN API. Before moving ahead, it is important to list the classes used and understand their role. This section will cover a few important classes defined in the