Consider the Following Reducer Code: 1 #!/Usr/bin/env Python3

question 55

Multiple Choice

Consider the following reducer code: 1 #!/usr/bin/env python3
2 # length_reducer.py
3 """Counts the number of words with each length."""
4 import sys
5 from itertools import groupby
6 from operator import itemgetter
7
8 def tokenize_input() :
9 """Split each line of standard input into a key and a value."""
10 for line in sys.stdin:
11 yield line.strip() .split('\t')
12
13 # produce key-value pairs of word lengths and counts separated by tabs
14 for word_length, group in groupby(tokenize_input() , itemgetter(0) ) :
15 try:
16 total = sum(int(count) for word_length, count in group)
17 print(word_length + '\t' + str(total) )
18 except ValueError:
19 pass # ignore word if its count was not an integer
Which of the following statements a) , b) or c) is false?

• A) When the MapReduce algorithm executes this reducer, lines 14-19 use the groupby function from the itertools module to group all word lengths of the same value. The first argument calls tokenize_input to get the lists representing the key-value pairs. The second argument indicates that the key-value pairs should be grouped based on the element at index 0 in each list-that is the key.
• B) Line 16 totals all the counts for a given key. Line 17 outputs a new key-value pair consisting of the word length and the total number of words of that length.
• C) The MapReduce algorithm takes all the final word length and count outputs and writes them to a file in HDFS-the Hadoop file system.
• D) All of the above statements are true.

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Definitions:

Overall Company Goals

Broad and general objectives that an organization seeks to achieve over a long-term period, guiding its mission and strategic direction.

Just-In-Time (JIT)

A production and inventory control system in which materials are purchased and units are produced only as needed to meet actual customer demand.

Customer Demand

The total amount of a product or service that consumers are willing to purchase at a given price level within a specific time period.

Just-In-Time (JIT)

A management strategy that aligns raw-material orders from suppliers directly with production schedules to reduce inventory costs and increase efficiency.