Using Hadoop for the First Time, MapReduce Job does not run Reduce Phase

Question

I wrote a simple map reduce job that would read in data from the DFS and run a simple algorithm on it. When trying to debug it I decided to simply make the mappers output a

Answer 1

The signature of your reduce method is wrong. Your method signature contains Iterator<Text>. You have to pass an Iterable<Text>.

Your code does not override the reduce method of the Reducer base class. Because of this, the default imlementation provided by the Reducer base class is used. This implementation is an identity function.

Use the @Override annotation to anticipate errors like this one.