We live in the age of Big Data Analytics and Data Analytics. Data is fueling everything, and so the demand for data workers has risen. Companies are constantly looking for skilled employees to help them make sense of the huge amounts of data they have. Are you preparing for a big data interview? Do you have questions or thoughts about the types of talks and questions you might be asked? It’s a good idea for you to have a general idea of the questions that will be asked before you go to a big-data interview. This will allow you to mentally prepare your responses. We have compiled a list with the top big data interview questions and their answers to help you understand the purpose and scope of big data interview question.
1. Describe the Vs of Big Data, and what is Big Data?
Big Data is a collection unstructured or semistructured data sets that can provide meaningful insights.
The four Vs of Big Data include -Volume – Talks about dataVariety and -Talks on the different formats of dataVelocity. -Talks regarding the ever increasing speed with which data is growingVeracity. -Talks concerning the accuracy of data available
2. What is the relationship between Hadoop & Big Data?
Hadoop is the most common term for Big Data. Hadoop is an open source platform that stores, processes, and analyses large amounts of unstructured data to generate intelligence and insights.
3. Discuss the definitions of HDFS and YARN and their respective components.
The HDFS is Hadoop’s default storage unit. It is responsible for storing various types of data in a distributed environment.
HDFS is made up of the following components:
NameNode – This master node holds the metadata information for all data blocks in the HDFS.
DataNode – These nodes act as slave nodes and store the data.
YARN is an acronym for Yet Another Resource Negotiator. It is responsible for managing resources as well as providing an execution environment.
4. Define commodity hardware
“Commodity hardware” is the minimum hardware requirement to run Apache Hadoop framework. ‘Commodity Hardware” refers to hardware that meets Hadoop’s basic criteria.
5. What does FSCK mean?
Filesystem Check (FSCK), is an acronym for Filesystem Check. It is a command that generates an Hadoop summary report summarizing HDFS’ current state. It only looks for errors and does not make them. This command can be used to execute a subset or the entire system.
6. What is Hadoop’s JPS command for?
The JPS command checks the functionality of all Hadoop Daemons. NameNode and DataNode, ResourceManager, NodeManager and other daemons can all be tested.
7. What commands can be used to launch and stop Hadoop Daemons
To start all the daemons:./sbin/start-all.sh
To shut down all the daemons:./sbin/stop-all.sh
8. Describe the many features of Hadoop.
Open-Source –Hadoop can be used as an open-source platform. It allows code to be rewritten and modified according to analytics and user requirements.
Scalability -Hadoop supports adding hardware resources to new nodes.
Data Recovery -Hadoop is a replication that allows data to be recovered in the event of a failure.
Data Locality – Hadoop moves computation to the data, and not the other direction. This speeds up the entire process.
9. What does the Port Numbers mean for NameNode Task Tracker, Job Tracker, and NameNode?
NameNode -Port 507070
Task Tracker -Port 5060
Job Tracker -Port 5030
10. What does HDFS indexing mean?
HDFS organizes data blocks into indexes according to their size. At the end of each data block is an indication of the address where the next chunk will be stored. The DataNodes store data blocks while the NameNode stores names.
11. What are Hadoop’s Edge Nodes and how do they work?
Gateway nodes are edge nodes.