This eBook is Chapter 5 from 'Software Testing in the Cloud: Perspectives on an Emerging Discipline' by Scott Tilley and Tahida Parveen. This chapter, coauthored by Eric Bower, discusses a software testing framework called HadoopUnit that integrates Hadoop and JUnit to facilitate the distribution of unit tests to the nodes of a cluster for concurrent execution. It was conceived of the need to reduce test execution time for large collections of tests and has been shown to successfully accomplish this in a medium-size cluster of 150 nodes. This work considers its effectiveness on a small cluster (4 nodes) to determine…....