Online Hadoop MapReduce Test – Practice For Hadoop Interview

by DataFlair Team · Published December 10, 2018 · Updated March 13, 2019

1. Hadoop Mapreduce Test

It seems that you have mastered the level  1 quiz. So are you ready for the next level? This Hadoop MapReduce test will consist of more of amateur level questions and less of the basics, so be prepared. The only motive behind this MapReduce quiz is to furnish your knowledge and build your accuracy on the questions regarding MapReduce because if you answer them correctly, that will raise your confidence ultimately leading to crack the Hadoop Interview.

Online Hadoop MapReduce Test – Practice For Hadoop Interview

So, All the Best.

Q.1 In MapReduce output of Mapper is stored on

Local Disk

HDFS

In-memory

Correct! Wrong!

Q.2 Which of the following is true about combiner

Reduces network congestion

Execution of combiner is not guaranteed

Both the above

Correct! Wrong!

Q.3 Which of the following is called Mini-reduce

Combiner

Partitioner

Reducer

Correct! Wrong!

Q.4 By default RecordReader uses which InputFormat for converting data into key-value pairs.

FileInputFormat

TextInputFormat

KeyValueTextInputFormat

SequenceFileInputFormat

Correct! Wrong!

Q.5 What statement is true about InputSplit?

Logical representation of data

Physical representation of data

Both the above

Correct! Wrong!

Q.6 Which of the following is not an input format in Hadoop?

TextInputFormat

KeyValueTextInputFormat

SequenceFileTextInputFormat

SequenceFileInputFormat

Correct! Wrong!

Q.7 In which InputFormat tab character (‘/t’) is used

KeyValueTextInputFormat

TextInputFormat

FileInputFormat

SequenceFileInputFormat

Correct! Wrong!

Q.8 Aggregation cannot be done in Mapper in MapReduce

True

False

Correct! Wrong!

Q.9 Shuffling and sorting phase in Hadoop occurs

First shuffling then sorting

Simultaneously

First sorting then shuffling

Correct! Wrong!

Q.10 What is the correct sequence of data flow in MapReduce

a. InputFormat

b. Shuffling-Sorting

c. Mapper

d. Reducer

e. OutputFormat

abcde

acdbe

acbde

bacde

Correct! Wrong!

Q.11 Which among the following is true about SequenceFileInputFormat

Key- byte offset. Value- It is the contents of the line

Key- Everything up to tab character. Value- Remaining part of the line after tab character

Key and value- Both are user-defined

None of the above

Correct! Wrong!

Q.12 Suppose file content is- "on the top of the Tree" then, what is key and value?

Key- 0 Value- on the top of the Tree

Key-on Value- the top of the Tree

Key-1 Value- on the top of the tree

Key-on the Value- top of the Tree

Correct! Wrong!

Q.13 Which among following is true about KeyValueTextInputFormat

Key- byte offset. Value- It is the contents of the line

Key- Everything up to tab character. Value- Remaining part of the line after tab character

Key and value- Both are user-defined

None of the above

Correct! Wrong!

Q.14 Which is key and value in TextInputFormat

Key- byte offset Value- It is the contents of the line

Key- Everything up to tab character Value- Remaining part of the line after tab character

Key and value- Both are user-defined

None of the above

Correct! Wrong!

Q.15 Counters validate that:

Number of bytes read-write within map/reduce job is correct or not

Number of tasks launches and successfully run in map/reduce job is correct or not

Amount of CPU and memory consumed is appropriate for our job and cluster nodes.

All of the above

Correct! Wrong!

Q.16 Which of the following is Built-In Counters in Hadoop?

FileSystem Counters

FileInputFormat Counters

FileOutputFormat counters

All of the above

Correct! Wrong!

Q.17 Which of the following command is used to set the number of reducers for the job

Job.confNumreduceTasks(int)

Job.setNumreduceTasks(int)

Job.setNumreduceTasks()

Job.confNumreduceTasks()

Correct! Wrong!

Q.18 Which of the following is not an output format in Hadoop?

TextoutputFormat

ByteoutputFormat

SequenceFileOutputFormat

DBOutputFormat

Correct! Wrong!

Q.19 Which of the following OutputFormat is used for writing to relational databases and Hbase?

TextoutputFormat

DBOutputFormat

MapFileOutputFormat

SequenceFileOutputFormat

Correct! Wrong!

Q.20 RecordReader handle record boundaries in Text files or Sequence files in MapReduce

True

False

Correct! Wrong!

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