Hadoop

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 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 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, use multiple nodes of which type?

  •  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

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 file 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

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

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