Friday, 21 December 2012

Why would a developer create a map-reduce without the reduce step? | Hadoop

A.  Developers should design Map-Reduce jobs without reducers only if no reduce slots are available on the cluster.
B.  Developers should never design Map-Reduce jobs without reducers. An error will occur upon compile.
C.  There is a CPU intensive step that occurs between the map and reduce steps. Disabling the reduce step speeds up data processing.
D.  It is not possible to create a map-reduce job without at least one reduce step. A developer may decide to limit to one reducer for debugging purposes.

Answer: C

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