Description of MapReduce concept:
http://java.dzone.com/articles/how-hadoop-mapreduce-works
Idea of mapper & reducer
Data flow for a single MapReduce job
Hadoop - my first MapReduce (M/R) code
...
http://java.dzone.com/articles/how-hadoop-mapreduce-works
Idea of mapper & reducer
Data flow for a single MapReduce job
...