With the adoption of YARN with Hadoop, the architecture for MapReduce programming framework and APIs were modified and the new framework is named MRv2. This chapter covered a brief about the differences between MRv1 and MRv2. It also explained the configuration changes, code compatibility, and monitoring of MRv1 applications when administrators and developers migrate from MRv1 to MRv2.
In the next chapter, you'll learn about writing your own YARN applications. This requires you to have basic knowledge of Java programming and is focused for developers who are eager to learn application development that is compatible with YARN.