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 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.

Q4. Hadoop Auth enforces authentication on protected resources. Once authentication has been established, it sets what type of authenticating cookie?

• 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<IntWritable> values, Context context){…}
• public static void reduce(Text key, IntWritable[] values, Context context){…}
• public static void reduce(Text key, Iterator<IntWritable> 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 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 (NOT SURE)
• 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 provides 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 (NOT SURE)
• 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

map function processes a certain key-value pair and emits a certain number of key-value pairs and the Reduce function processes values grouped by the same key and emits another set of key-value pairs as output.

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 (https://data-flair.training/blogs/hadoop-high-availability-tutorial)

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 numbers 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 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 object?

• 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 <fromDir> <toDir>
• hadoop fs -copy <toDir> <fromDir>
• hadoop fs -copyFromLocal <fromDir> <toDir>
• hadoop fs -copyFromLocal <toDir> <fromDir>

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 Hadoop MapReduce job code, what must be static?

• configuration
• Mapper and Reducer
• Mapper
• Reducer

Reference

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

• Kerberos ticket
• kubernetes token
• guest operating system
• host operating system

Reference

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

• FileReader
• CompositeInputFormat
• RecordReader
• TextInputFormat

Reference

Q75. If you see org.apache.hadoop.mapred, which version of MapReduce are you working with?

• 1.x
• 0.x
• 2.x
• 3.x

Reference