Time for action – reduce-side join using MultipleInputs

We can perform the report explained in the previous section using a reduce-side join by performing the following steps:

1. Create the following tab-separated file and name it sales.txt:

   00135.992012-03-15
   00212.492004-07-02
   00413.422005-12-20
   003499.992010-12-20
   00178.952012-04-02
   00221.992006-11-30
   00293.452008-09-10
   0019.992012-05-17

2. Create the following tab-separated file and name it accounts.txt:

   001John AllenStandard2012-03-15
   002Abigail SmithPremium2004-07-13
   003April StevensStandard2010-12-20
   004Nasser HafezPremium2001-04-23

3. Copy the datafiles onto HDFS.

   $ hadoop fs -mkdir sales
   $ hadoop fs -put sales.txt sales/sales.txt
   $ hadoop fs -mkdir accounts
   $ hadoop fs -put accounts/accounts.txt
   

4. Create the following file and name it ReduceJoin.java:

   import java.io.* ;
   
   import org.apache.hadoop.conf.Configuration;
   import org.apache.hadoop.fs.Path;
   import org.apache.hadoop.io.Text;
   import org.apache.hadoop.mapreduce.*;
   import org.apache.hadoop.mapreduce...