In this chapter, we started by checking the prerequisites for how to install Hadoop and configured Hadoop in the pseudo-distributed mode. Then, we got the Elasticsearch server up and running and understood the basic configurations of Elasticsearch. We learned how to install the Elasticsearch plugins. We imported the sample file for the WordCount example to HDFS and successfully ran our first Hadoop MapReduce job that uses ES-Hadoop to get the data to Elasticsearch. Then we learned how to use the Head and Marvel plugins to explore documents in Elasticsearch.

With our environment and the required tools set up with a basic understanding, we are all set to have a hands-on experience of how to write MapReduce jobs that use ES-Hadoop. In the next chapter, we will take a look at how the WordCount job is developed. We will also develop a couple of jobs for real-world scenarios that will write and read data to and from HDFS and Elasticsearch.