Hadoop development started in 2005 and in December 2011, it reached version 1.0.0. Enterprises started using Hadoop and implemented data processing algorithms based on the MapReduce programming framework. In 2013, Hadoop version 2.2.0 was released and the MapReduce framework went through a lot of architectural changes. A generic framework for resource management, that is, YARN was introduced and architecture for MapReduce job execution over a Hadoop cluster changed. The old API of the framework is known as MRv1 and the MapReduce APIs associated with YARN framework are termed as MRv2.
In this chapter, we will cover the following:
Introduction MRv1 and MRv2
Migrating to MRv2
Running and monitoring MRv1 apps on YARN