Here, We see Hadoop LinkedIn Skill Assessment Answer. This assessment test consists of 15-20 MCQs to demonstrate your knowledge of your selected skills. MCQs come from different topics – Hadoop Common, Hadoop Components, Hadoop Concepts, MapReduce, and Using Hadoop..

List of all LinkedIn Skills Assessment Answer

Hadoop LinkedIn Skill Assessment Answer

Q1. Partitioner controls the partitioning of what data?

final keys
final values
intermediate keys✔
intermediate values

Q2. SQL Windowing functions are implemented in Hive using which keywords?

UNION DISTINCT, RANK
OVER, RANK✔
OVER, EXCEPT
UNION DISTINCT, RANK

Q3. Rather than adding a Secondary Sort to a slow Reduce job, it is Hadoop’s best practice to perform which optimization?

Add a partitioned shuffle to the Map job.
Add a partitioned shuffle to the Reduce job.✔
Break the Reduce job into multiple, chained Reduce jobs.
Break the Reduce job into multiple, chained Map jobs.

encrypted HTTP
unsigned HTTP
compressed HTTP
signed HTTP✔

Q5. MapReduce jobs can be written in which language?

Java or Python✔
SQL only
SQL or Java
Python or SQL

Q6. To perform local aggregation of the intermediate outputs, MapReduce users can optionally specify which object.

Reducer
Combiner✔
Mapper
Counter

Q7. To verify job status, look for the value _ in the _.

SUCCEEDED; syslog
SUCCEEDED; stdout✔
DONE; syslog
DONE; stdout

Q8. Which line of code implements a Reducer method in MapReduce 2.0?

public void reduce(Text key, Iterator values, Context context){…}✔
public static void reduce(Text key, IntWritable[] values, Context context){…}
public static void reduce(Text key, Iterator values, Context context){…}
public void reduce(Text key, IntWritable[] values, Context context){…}

Q9. To get the total number of mapped input records in a map job task, you should review the value of which counter?

FileInputFormatCounter
FileSystemCounter
JobCounter
TaskCounter (NOT SURE)✔

Q10. Hadoop Core supports which CAP capabilities?

A, P✔
C, A
C, P
C, A, P

Q11. What are the primary phases of a Reducer?

combine, map, and reduce
shuffle, sort, and reduce✔
reduce, sort, and combine
map, sort, and combine

Q12. To set up a Hadoop workflow with synchronization of data between jobs that process tasks both on disk and in memory, use the _ service, which is _.

Oozie; Open-source
Oozie; commercial software
Zookeeper; commercial software
Zookeeper; open source✔

Q13. For high availability, which type of multiple nodes should you use?

data
name✔
memory
worker

Q14. DataNode supports which type of drives?

hot swappable✔
cold swappable
warm swappable
non-swappable

Q15. Which method is used to implement Spark jobs?

on disk of all workers
on disk of the master node
in memory of the master node
in memory of all workers✔

Q16. In a MapReduce job, where does the map() function run?

on the reducer nodes of the cluster
on the data nodes of the cluster✔
on the master node of the cluster
on every node of the cluster

Q17. To reference a master file for lookups during Mapping, what type of cache should be used?

distributed cache✔
local cache
partitioned cache
cluster cache

Q18. Skip bad records provide an option where a certain set of bad input records can be skipped when processing what type of data?

cache inputs
reducer inputs
intermediate values
map inputs✔

Q19. Which command imports data to Hadoop from a MySQL database?

spark import –connect jdbc:mysql://mysql.example.com/spark –username spark –warehouse-dir user/hue/oozie/deployments/spark
sqoop import –connect jdbc:mysql://mysql.example.com/sqoop –username sqoop –warehouse-dir user/hue/oozie/deployments/sqoop
sqoop import –connect jdbc:mysql://mysql.example.com/sqoop –username sqoop –password sqoop –warehouse-dir user/hue/oozie/deployments/sqoop✔
spark import –connect jdbc:mysql://mysql.example.com/spark –username spark –password spark –warehouse-dir user/hue/oozie/deployments/spark

Q20. In what form is Reducer output presented?

compressed✔
sorted
not sorted
encrypted

Q21. Which library should be used to unit test MapReduce code?

JUnit
XUnit
MRUnit✔
HadoopUnit

Q22. If you started the NameNode, then which kind of user must you be?

hadoop-user
super-user✔
node-user
admin-user

Q23. State _ between the JVMs in a MapReduce job

can be configured to be shared
is partially shared
is shared
is not shared (https://www.lynda.com/Hadoop-tutorials/Understanding-Java-virtual-machines-JVMs/191942/369545-4.html)✔

Q24. To create a MapReduce job, what should be coded first?

a static job() method
a Job class and instance (NOT SURE)✔
a job() method
a static Job class

Q25. To connect Hadoop to AWS S3, which client should you use?

S3A✔
S3N
S3
the EMR S3

Q26. HBase works with which type of schema enforcement?

schema on write
no schema
external schema
schema on read✔

Q27. HDFS files are of what type?

read-write
read-only
write-only
append-only✔

Q28. A distributed cache file path can originate from what location?

hdfs or top
http
hdfs or http✔
hdfs

Q29. Which library should you use to perform ETL-type MapReduce jobs?

Hive
Pig✔
Impala
Mahout

Q30. What is the output of the Reducer?

a relational table
an update to the input file
a single, combined list
a set of <key, value> pairs✔

Q31. To optimize a Mapper, what should you perform first?

Override the default Partitioner.
Skip bad records.
Break up Mappers that do more than one task into multiple Mappers.✔
Combine Mappers that do one task into large Mappers.

Q32. When implemented on a public cloud, with what does Hadoop processing interact?

files in object storage✔
graph data in graph databases
relational data in managed RDBMS systems
JSON data in NoSQL databases

Q33. In the Hadoop system, what administrative mode is used for maintenance?

data mode
safe mode✔
single-user mode
pseudo-distributed mode

Q34. In what format does RecordWriter write an output file?

<key, value> pairs✔
keys
values
<value, key> pairs

Q35. To what does the Mapper map input key/value pairs?

an average of keys for values
a sum of keys for values
a set of intermediate key/value pairs✔
a set of final key/value pairs

Q36. Which Hive query returns the first 1,000 values?

SELECT…WHERE value = 1000
SELECT … LIMIT 1000✔
SELECT TOP 1000 …
SELECT MAX 1000…

Q37. To implement high availability, how many instances of the master node should you configure?

one
zero
shared
two or more✔

Q38. Hadoop 2.x and later implement which service as the resource coordinator?

Kubernetes
JobManager
JobTracker
YARN✔

Q39. In MapReduce, _ have _

tasks; jobs
jobs; activities
jobs; tasks✔
activities; tasks

Q40. What type of software is Hadoop Common?

database
distributed computing framework✔
operating system
productivity tool

Q41. If no reduction is desired, you should set the number of _ tasks to zero.

combiner
reduce✔
mapper
intermediate

Q42. MapReduce applications use which of these classes to report their statistics?

mapper
reducer
combiner
counter✔

Q43. _ is the query language, and _ is storage for NoSQL on Hadoop.

HDFS; HQL
HQL; HBase✔
HDFS; SQL
SQL; HBase

Q44. MapReduce 1.0 _ YARN.

does not include✔
is the same thing as
includes
replaces

Q45. Which type of Hadoop node executes file system namespace operations like opening, closing, and renaming files and directories?

ControllerNode
DataNode
MetadataNode
NameNode✔

Q46. HQL queries produce which job types?

Impala
MapReduce✔
Spark
Pig

Q47. Suppose you are trying to finish a Pig script that converts text in the input string to uppercase. What code is needed on line 2 below?

1 data = LOAD '/user/hue/pig/examples/data/midsummer.txt'... 2

as (text:CHAR[]); upper_case = FOREACH data GENERATE org.apache.pig.piggybank.evaluation.string.UPPER(TEXT);
as (text:CHARARRAY); upper_case = FOREACH data GENERATE org.apache.pig.piggybank.evaluation.string.UPPER(TEXT);✔
as (text:CHAR[]); upper_case = FOREACH data org.apache.pig.piggybank.evaluation.string.UPPER(TEXT);
as (text:CHARARRAY); upper_case = FOREACH data org.apache.pig.piggybank.evaluation.string.UPPER(TEXT);

Q48. In a MapReduce job, which phase runs after the Map phase completes?

Combiner✔
Reducer
Map2
Shuffle and Sort

Q49. Where would you configure the size of a block in a Hadoop environment?

dfs.block.size in hdfs-site.xmls✔
orc.write.variable.length.blocks in hive-default.xml
mapreduce.job.ubertask.maxbytes in mapred-site.xml
hdfs.block.size in hdfs-site.xml

Q50. Hadoop systems are _ RDBMS systems.

replacements for
not used with
substitutes for
additions for✔

Q51. Which object can be used to distribute jars or libraries for use in MapReduce tasks?

distributed cache✔
library manager
lookup store
registry

Q52. To view the execution details of an Impala query plan, which function would you use?

explain✔
query action
detail
query plan

Q53. Which feature is used to roll back a corrupted HDFS instance to a previously known good point in time?

partitioning
snapshot✔
replication
high availability

Reference

Q54. Hadoop Common is written in which language?

C++
C
Haskell
Java✔

Q55. Which file system does Hadoop use for storage?

NAS
FAT
HDFS✔
NFS

Q56. What kind of storage and processing does Hadoop support?

encrypted
verified
distributed✔
remote

Q57. Hadoop Common consists of which components?

Spark and YARN
HDFS and MapReduce✔
HDFS and S3
Spark and MapReduce

Q58. Most Apache Hadoop committers’ work is done at which commercial company?

Cloudera
Microsoft
Google
Amazon✔

Q59. To get information about the Reducer job runs, which object should be added?

Reporter✔
IntReadable
IntWritable
Writer

Q60. After changing the default block size and restarting the cluster, to which data does the new size apply?

all data
no data
existing data
new data✔

Q61. Which statement should you add to improve the performance of the following query?

SELECT
  c.id,
  c.name,
  c.email_preferences.categories.surveys
FROM customers c;

GROUP BY
FILTER
SUB-SELECT
SORT✔

Q62. What custom object should you implement to reduce IO in MapReduce?

Comparator
Mapper
Combiner✔
Reducer

Q63. You can optimize Hive queries using which method?

secondary indices✔
summary statistics
column-based statistics
a primary key index

Q64. If you are processing a single action on each input, what type of job should you create?

partition-only
map-only✔
reduce-only
combine-only

Q65. The simplest possible MapReduce job optimization is to perform which of these actions?

Add more master nodes.
Implement optimized InputSplits.✔
Add more DataNodes.
Implement a custom Mapper.

Q66. When you implement a custom Writable, you must also define which of these objects?

a sort policy
a combiner policy✔
a compression policy
a filter policy

Q67. To copy a file into the Hadoop file system, what command should you use?

hadoop fs -copy
hadoop fs -copy
hadoop fs -copyFromLocal✔
hadoop fs -copyFromLocal

Q68. Delete a Hive _ table and you will delete the table _.

managed; metadata
external; data and metadata
external; metadata
managed; data✔

Q69. To see how Hive executed a JOIN operation, use the _ statement and look for the _ value.

EXPLAIN; JOIN Operator✔
QUERY; MAP JOIN Operator
EXPLAIN; MAP JOIN Operator
QUERY; JOIN Operator

Q70. Pig operates in mainly how many nodes?

Two✔
Three
Four
Five

Q71. After loading data, _ and then run a(n) _ query for interactive queries.

invalidate metadata; Impala✔
validate metadata; Impala
invalidate metadata; Hive
validate metadata; Hive

Q72. In the Hadoop MapReduce job code, what must be static?

configuration
Mapper and Reducer✔
Mapper
Reducer

Q73. In Hadoop simple mode, which object determines the identity of a client process?

Kerberos ticket
Kubernetes token
guest operating system
host operating system✔

Q74. Which is not a valid input format for a MapReduce job?

FileReader✔
CompositeInputFormat
RecordReader
TextInputFormat