In this article, I am going to explain how to use Hadoop streaming with Perl scripts. First, let’s understand some theory behind Hadoop streaming. Hadoop has been written in Java. Therefore, the native language to write MapReduce program is Java. But, Hadoop also provide an API to MapReduce that allows …
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Implementing Security in Hadoop Cluster
When we talk about security in Hadoop, we need to explore all the aspect of cluster networking and understand how the Nodes and Client communicate to each other. Let’s list down possible communication in a simple cluster. Master – Slave communication => Namenode – Datanode / Jobtracker – Tasktracker communication …
Tool & ToolRunner – Simplifying the concept
Writing a mapper & reducer Program definition is easy. Just extend your class by org.apache.hadoop.mapreduce.Mapper and org.apache.hadoop.mapreduce.Reducer respectively and override the map and reduce methods to implement your logics. But, when it comes to write driver program (contain main method of program) for the MapReduce Job, it’s always preferable to …
Developing Java Map-Reduce on local machine to run on Hadoop Cluster
Introduction In this post, I have explained how to develop hadoop jobs in Java and export JAR to run on Hadoop clusters. Most of the articles on internet, talk about installing eclipse-plugin and using maven or ANT to build JAR. To install eclipse-plugin for hadoop, one needs to install eclipse …