Big Data Simplified

94 | Big Data Simplied

Summary

Each mapper will produce key value pairs as

its output. That output is the input for inter-

mediate events. Each code represents a specic

key, in this above case, a member name.

Internally, the framework has a partition

function that it runs to determine where each

key goes. There is just one job for the parti-

tion function and that is to look at the key and

determine which partition or node it belongs

to. Here, if required to break the level of

MapReduce output using multiple resuceri.g

different salary grade of Employee, then

develop a custom partitioner to overwrite the

default partitioner api.

A Combiner, also ...