Hadoop Beginner's Guide

Time for action – running WordCount on a local Hadoop cluster

Now we have generated the class files and collected them into a JAR file, we can run the application by performing the following steps:

1. Submit the new JAR file to Hadoop for execution.

   $ hadoop jar wc1.jar WordCount1 test.txt output
   

2. If successful, you should see the output being very similar to the one we obtained when we ran the Hadoop-provided sample WordCount in the previous chapter. Check the output file; it should be as follows:

   $ Hadoop fs –cat output/part-r-00000
   This 1
   yes 1
   a 1
   is 2
   test 1
   this 1
   

What just happened?

This is the first time we have used the Hadoop JAR command with our own code. There are four arguments:

1. The name of the JAR file.
2. The name of the driver class within ...