Top 25 Big Data Interview Questions and Answers You Must Prepare for in 2018

Interview Question and Answers:

1. What do you understand by the term 'big data'?

Big data deals with complex and large sets of data that cannot be handled using conventional software.

2. How is big data useful for businesses?

Big Data helps organizations understand their customers better by allowing them to draw conclusions from large data sets collected over the years. It helps them make better decisions.

3. What is the Port Number for NameNode?

NameNode – Port 50070

4. What is the function of the JPS command?

 The JPS command is used to test whether all the Hadoop daemons are running correctly or not.

5. What is the command to start up all the Hadoop daemons together?

./sbin/start-all.sh

6. Name a few features of Hadoop.

 Some of the most useful features of Hadoop,

1. It's open source nature.

2. User-friendly.

3. Scalability.

4. Data locality.

5. Data recovery.

7. What are the five V’s of Big Data?

 The five V’s of Big data are Volume, Velocity, Variety, Veracity, and Value.

8. What are the components of HDFS?

 The two main components of HDFS are:

1. Name Node

2. Data Node

9. How is Hadoop related to Big Data?

Hadoop is a framework that specializes in big data operations.

10. Name a few data management tools used with Edge Nodes?

Oozie, Flume, Ambari, and Hue are some of the data management tools that work with edge nodes in Hadoop.

11. What are the steps to deploy a Big Data solution?

The three steps to deploying a Big Data solution are:

1. Data Ingestion

2. Data Storage and

3. Data Processing

12. How many modes can Hadoop be run in?

 Hadoop can be run in three modes— Standalone mode, Pseudo-distributed mode and fully-distributed mode.

13.    Name the core methods of a reducer

 The three core methods of a reducer are,

1. setup()

2. reduce()

3. cleanup()

14.    What is the command for shutting down all the Hadoop Daemons together?

./sbin/stop-all.sh

15. What is the role of NameNode in HDFS?

NameNode is responsible for processing metadata information for data blocks within HDFS.

16. What is FSCK?

FSCK (File System Check) is a command used to detect inconsistencies and issues in the file.

17. What are the real-time applications of Hadoop?

 Some of the real-time applications of Hadoop are in the fields of:

• Content management.

• Financial agencies.

• Defense and cybersecurity.

• Managing posts on social media.

18. What is the function of HDFS?

 The HDFS (Hadoop Distributed File System) is Hadoop’s default storage unit. It is used for storing different types of data in a distributed environment.

19. What is commodity hardware?

Commodity hardware can be defined as the basic hardware resources needed to run the Apache Hadoop framework.

20. Name a few daemons used for testing JPS command.

• NameNode

• NodeManager

• DataNode

• ResourceManager

21. What are the most common input formats in Hadoop?

• Text Input Format

• Key Value Input Format

• Sequence File Input Format

22. Name a few companies that use Hadoop.

 Yahoo, Facebook, Netflix, Amazon, and Twitter.

23. What is the default mode for Hadoop?

 Standalone mode is Hadoop's default mode. It is primarily used for debugging purpose.

24. What is the role of Hadoop in big data analytics?

By providing storage and helping in the collection and processing of data, Hadoop helps in the analytics of big data.

25. What are the components of YARN?

 The two main components of YARN (Yet Another Resource Negotiator) are:

• Resource Manager

• Node Manager

Conclusion:

We have tried to gather all the essential information required for the interview but know that big data is a vast topic and several other questions can be asked too. Prepare for the interview based on the type of industry you are applying for and some of the sample answers provided here vary with the type of industry.

All in all, be honest and positive as it outshines all other qualities.