This chapter explains how to set up Hadoop to run on a cluster of machines. Running HDFS and MapReduce on a single machine is great for learning about these systems, but to do useful work they need to run on multiple nodes.

There are a few options when it comes to getting a Hadoop cluster, from building your own, to running on rented hardware or using an offering that provides Hadoop as a service in the cloud. This chapter and the next give you enough information to set up and operate your own cluster, but even if you are using a Hadoop service in which a lot of the routine maintenance is done for you, these chapters still offer valuable information about how Hadoop works from an operations point of view.