In this chapter, we have learned the essentials of HDFS, such as file operations on HDFS and how to configure HDFS. We looked at the namenode and secondary namenode web interfaces and explored a few HDFS commands. We also covered the MapReduce architecture along with a detailed walkthrough of the namenode and jobtracker web interfaces.

In the next chapter, we will dive into Cloudera's Distribution Including Apache Hadoop (CDH).