Hadoop Beginner's Guide

Time for action – importing data from Hadoop into MySQL

Let's demonstrate this by importing data into a MySQL table from an HDFS file.

1. Create a tab-separated file named newemployees.tsv with the following entries:

   Frances  Operations  34000  2012-03-01
   Greg  Engineering  60000  2003-11-18
   Harry  Intern  22000  2012-05-15
   Iris  Executive  80000  2001-04-08
   Jan  Support  28500  2009-03-30

2. Create a new directory on HDFS and copy the file into it:

   $hadoop fs -mkdir edata
   $ hadoop fs -put newemployees.tsv edata/newemployees.tsv
   

3. Confirm the current number of records in the employee table:

   $ echo "select count(*) from employees" | 
   mysql –u hadoopuser –p hadooptest
   

   You will receive the following response:

   Enter password: 
   count(*)
   5
   

4. Run a Sqoop export:

   $ sqoop export ...