Question

Point out the wrong statement.

(a) It is legal to set the number of reduce-tasks to zero if no reduction is desired

(b) The outputs of the map-tasks go directly to the FileSystem

(c) The Mapreduce framework does not sort the map-outputs before writing them out to the FileSystem

(d) None of the mentioned

This question was addressed to me during an online interview.

I'm obligated to ask this question of MapReduce Features in chapter Developing a MapReduce Application of Hadoop

Answer 1

Right choice is (d) None of the mentioned

Explanation: Outputs of the map-tasks go directly to the FileSystem, into the output path set by setOutputPath(Path).