In this chapter, we have took a deep dive into HDFS. We tried to figure out how HDFS works and its key features. We looked at different data flow patterns of HDFS, where we can see HDFS in different roles. This was supported with various configuration files of HDFS and key attributes. We also looked at various command-line interface commands for HDFS and the Hadoop shell. Finally, we looked at the data structures that are used by HDFS with some examples.
In the next chapter, we will study the creation of a new MapReduce application with Apache Hadoop MapReduce.