What is the purpose of shuffling and sorting phase in the reducer in Map Reduce Programming?

Question

In Map Reduce programming the reduce phase has shuffling, sorting and reduce as its sub-parts. Sorting is a costly affair.

What is the purpose of shuffling and sorting phase in the reducer in Map Reduce Programming?

Answer 1

Hi!

Follow this tutorial on MapReduce: https://intellipaat.com/blog/tutorial/hadoop-tutorial/what-is-yarn/