Hadoop and MapReduce  MCQs

By: Prof. Dr. Fazal Rehman | Last updated: May 14, 2025

1. : What is Hadoop primarily used for?
(A) Data visualization
(B) Large-scale data processing
(C) Database management
(D) Network security

2. : Which component of Hadoop is responsible for distributed storage?
(A) MapReduce
(B) YARN
(C) HDFS
(D) Hive

3. : What does HDFS stand for?
(A) Hadoop Distributed File System
(B) Hadoop Data File Storage
(C) Highly Distributed File System
(D) Hadoop Data File System

4. : Which component of Hadoop is responsible for resource management and job scheduling?
(A) HDFS
(B) YARN
(C) MapReduce
(D) Hive

5. : How does Hadoop achieve fault tolerance?
(A) By replicating data across multiple nodes
(B) By using a single powerful server
(C) By storing data in memory
(D) By using a centralized database

6. : What is the primary purpose of the MapReduce programming model?
(A) Data storage
(B) Data visualization
(C) Parallel data processing
(D) Network communication

7. : In MapReduce, what is the role of the “Map” function?
(A) To sort the data
(B) To process input data and produce intermediate key-value pairs
(C) To combine the results
(D) To store the output data

8. : What does the “Reduce” function do in the MapReduce framework?
(A) It processes intermediate key-value pairs and produces the final output
(B) It sorts the data
(C) It splits the data into chunks
(D) It combines multiple files into one

9. : In a MapReduce job, where is the intermediate data stored between the Map and Reduce phases?
(A) HDFS
(B) Local file system of the mapper nodes
(C) Memory of the reducer nodes
(D) YARN resource manager

10. : What is the role of the Combiner function in MapReduce?
(A) To combine the output of multiple reducers
(B) To perform local aggregation of intermediate results before passing them to the reducer
(C) To split the input data
(D) To sort the final output

11. : Which Hadoop ecosystem component is used for querying and managing large datasets residing in distributed storage using SQL?
(A) Pig
(B) Hive
(C) HBase
(D) Sqoop

12. : What is Apache Pig used for in the Hadoop ecosystem?
(A) High-level scripting for data analysis
(B) SQL-based querying
(C) Real-time data processing
(D) Data visualization

13. : Which component of the Hadoop ecosystem provides a NoSQL database that runs on top of HDFS?
(A) Pig
(B) Hive
(C) HBase
(D) Sqoop

14. : What is the primary function of Apache Sqoop?
(A) To move bulk data between Hadoop and structured datastores
(B) To perform real-time processing
(C) To visualize data
(D) To provide a distributed file system

15. : Which component of the Hadoop ecosystem is used for real-time stream processing?
(A) Flume
(B) Oozie
(C) Spark
(D) Kafka

16. : What is the default block size in HDFS?
(A) 32 MB
(B) 64 MB
(C) 128 MB
(D) 256 MB

17. : How does Hadoop ensure data integrity in HDFS?
(A) By using checksums
(B) By storing multiple copies of the same data
(C) By using encryption
(D) By storing data in memory

18. : Which component in YARN is responsible for tracking the status of applications?
(A) ResourceManager
(B) NodeManager
(C) ApplicationMaster
(D) JobTracker

19. : What is the role of the ResourceManager in YARN?
(A) To manage the global assignment of resources to applications
(B) To execute MapReduce jobs
(C) To store the input data
(D) To manage data replication

20. : Which of the following is a benefit of using Hadoop for data mining?
(A) Scalability
(B) High cost
(C) Centralized data storage
(D) Limited fault tolerance