Categories
News

Big Data Interview Questions And Answers

Our experts providing  Big Data  interview questions & Answers/Faqs can develop your carrier & knowledge to find the right job in a good MNC’s, doesn’t matter what kind of company you’re hired.

1)Explain “Big Data” and what are five V’s of Big Data?
“Big data” is the term for a collection of large and complex data sets, that makes it difficult to process using relational database management tools or traditional data processing applications. It is difficult to capture, curate, store, search, share, transfer, analyze, and visualize Big data. Big Data has emerged as an opportunity for companies. Now they can successfully derive value from their data and will have a distinct advantage over their competitors with enhanced business decisions making capabilities.

♣ Tip: It will be a good idea to talk about the 5Vs in such questions, whether it is asked specifically or not!

Volume: The volume represents the amount of data which is growing at an exponential rate i.e. in Petabytes and Exabytes.
Velocity: Velocity refers to the rate at which data is growing, which is very fast. Today, yesterday’s data are considered as old data. Nowadays, social media is a major contributor in the velocity of growing data.
Variety: Variety refers to the heterogeneity of data types. In another word, the data which are gathered has a variety of formats like videos, audios, csv, etc. So, these various formats represent the variety of data.
Veracity: Veracity refers to the data in doubt or uncertainty of data available due to data inconsistency and incompleteness. Data available can sometimes get messy and maybe difficult to trust. With many forms of big data, quality and accuracy are difficult to control. The volume is often the reason behind for the lack of quality and accuracy in the data.
Value: It is all well and good to have access to big data but unless we can turn it into a value it is useless. By turning it into value I mean, Is it adding to the benefits of the organizations? Is the organization working on Big Data achieving high ROI (Return On Investment)? Unless, it adds to their profits by working on Big Data, it is useless.

2)What is Hadoop and its components.
When “Big Data” emerged as a problem, Apache Hadoop evolved as a solution to it. Apache Hadoop is a framework which provides us various services or tools to store and process Big Data. It helps in analyzing Big Data and making business decisions out of it, which can’t be done efficiently and effectively using traditional systems.

♣ Tip: Now, while explaining Hadoop, you should also explain the main components of Hadoop, i.e.:

Storage unit– HDFS (NameNode, DataNode)
Processing framework– YARN (ResourceManager, NodeManager)

3)Name some companies that use Hadoop.?

  • Yahoo (One of the biggest user & more than 80% code contributor to Hadoop)
  • Facebook
  • Netflix
  • Amazon
  • Adobe
  • eBay
  • Hulu
  • Spotify
  • Rubikloud
  • Twitter

4)What are active and passive “NameNodes”?
In HA (High Availability) architecture, we have two NameNodes – Active “NameNode” and Passive “NameNode”.

Active “NameNode” is the “NameNode” which works and runs in the cluster.
Passive “NameNode” is a standby “NameNode”, which has similar data as active “NameNode”.
When the active “NameNode” fails, the passive “NameNode” replaces the active “NameNode” in the cluster. Hence, the cluster is never without a “NameNode” and so it never fails.

5)What is a checkpoint?
In brief, “Checkpointing” is a process that takes an FsImage, edit log and compacts them into a new FsImage. Thus, instead of replaying an edit log, the NameNode can load the final in-memory state directly from the FsImage. This is a far more efficient operation and reduces NameNode startup time. Checkpointing is performed by Secondary NameNode.

6)What is the port number for NameNode, Task Tracker and Job Tracker?

  • NameNode 50070
  • Job Tracker 50030
  • Task Tracker 50060

7)What does ‘jps’ command do?
The ‘jps’ command helps us to check if the Hadoop daemons are running or not. It shows all the Hadoop daemons i.e namenode, datanode, resourcemanager, nodemanager etc. that are running on the machine.

8) Explain about the indexing process in HDFS?
Indexing process in HDFS depends on the block size. HDFS stores the last part of the data that further points to the address where the next part of data chunk is stored.

9)Whenever a client submits a hadoop job, who receives it?

NameNode receives the Hadoop job which then looks for the data requested by the client and provides the block information. JobTracker takes care of resource allocation of the hadoop job to ensure timely completion.

10)What are the main configuration parameters in a “MapReduce” program?
The main configuration parameters which users need to specify in “MapReduce” framework are:

Job’s input locations in the distributed file system
Job’s output location in the distributed file system
Input format of data
Output format of data
Class containing the map function
Class containing the reduce function
JAR file containing the mapper, reducer and driver classes

11)What is the purpose of “RecordReader” in Hadoop?
The “InputSplit” defines a slice of work, but does not describe how to access it. The “RecordReader” class loads the data from its source and converts it into (key, value) pairs suitable for reading by the “Mapper” task. The “RecordReader” instance is defined by the “Input Format”.

12)How do “reducers” communicate with each other?
This is a tricky question. The “MapReduce” programming model does not allow “reducers” to communicate with each other. “Reducers” run in isolation.

13)What is a “Combiner”?
A “Combiner” is a mini “reducer” that performs the local “reduce” task. It receives the input from the “mapper” on a particular “node” and sends the output to the “reducer”. “Combiners” help in enhancing the efficiency of “MapReduce” by reducing the quantum of data that is required to be sent to the “reducers”.

14) What are the different relational operations in “Pig Latin” you worked with?

Different relational operators are:

  • for each
  • order by
  • filters
  • group
  • distinct
  • join
  • limit

15) What is a UDF?
If some functions are unavailable in built-in operators, we can programmatically create User Defined Functions (UDF) to bring those functionalities using other languages like Java, Python, Ruby, etc. and embed it in Script file.

16)What are the components of Apache HBase?
HBase has three major components, i.e. HMaster Server, HBase RegionServer and Zookeeper.

Region Server: A table can be divided into several regions. A group of regions is served to the clients by a Region Server.
HMaster: It coordinates and manages the Region Server (similar as NameNode manages DataNode in HDFS).
ZooKeeper: Zookeeper acts like as a coordinator inside HBase distributed environment. It helps in maintaining server state inside the cluster by communicating through sessions.

17) Explain about the different catalog tables in HBase?

The two important catalog tables in HBase, are ROOT and META. ROOT table tracks where the META table is and META table stores all the regions in the system.

18)Differentiate between Sqoop and distCP.

DistCP utility can be used to transfer data between clusters whereas Sqoop can be used to transfer data only between Hadoop and RDBMS.

19)How would you check whether your NameNode is working or not?

There are several ways to check the status of the NameNode. Mostly, one uses the jps command to check the status of all daemons running in the HDFS

20)What is checkpointing in Hadoop?
Checkpointing is the process of combining the Edit Logs with the FsImage (File system Image). It is performed by the Secondary NameNode……….. For more click here


For Course content click here

Categories
BigData

Big Data Online Training

Our Institute offers online Big Data training with Big Data certification material. Learn Big Data course by real time experts, record live tutorial videos. Attend the demo for free & you will find Spiritsofts is the best Institute within reasonable fee. Big data online training. In this module HDFS, MapReduce, HIVE, HBASE, SQOOP, Flume, PIG, Spark and Scala

Spiritsofts is the best Training Institutes to expand your skills and knowledge. We Provides the best learning Environment. Obtain all the training by our expert professionals which is having working experience from Top IT companies.

The Training in is every thing we explained based on real time scenarios, it works which we do in companies.

Experts Training sessions will absolutely help you to get in-depth knowledge on the subject.

Key FeaturesCourse ContentFAQs
  • 45 hours of Instructor Training Classes    
  • Lifetime Access to Recorded Sessions  
  • Real World use cases and Scenarios 
  • 24/7 Support
  • Practical Approach
  •  Expert & Certified Trainers

Big Data Course Content

Introduction to Big Data and Hadoop

  • What is Big Data
  • What is Hadoop
  • Why Hadoop
  • Hadoop trends
  • Technologies supports Big Data
  • RDBMS vs. Hadoop
  • Ecosystems of Hadoop
  • Hardware Recommendations

Core Idea of Big Data

  • Storage
  • Processing

Hadoop Vs Other Data warehouse tools

  • RDBMS
  • Informatica
  • Teradata

HDFS

  • What is HDFS
  • Features of HDFS
  • Daemons of HDFS
    • Name Node
    • Data Node
    • Secondary Name Node
  • Data Storage in HDFS
  • Introduction about Blocks
  • Data replication
  • Accessing HDFS
  • CLI (Command Line Interface) and admin commands
  • Java API
  • Fault tolerance

MapReduce

  • What is Map Reduce
  • Map Reduce Architecture
  • Daemons of MapReduce
    • Job Tracker
    • Task Tracker
  • How Map Reduce works
  • Working with Map Reduce Programming
  • Different formats in Map Reduce
  • Data localization
  • Performance in Map Reduce program
  • Debugging Map Reduce Job

HIVE

  • Hive introduction
  • Hive architecture
  • Hive vs. RDBMS
  • HiveQL and the shell
  • Different types of HIVE tables
  • HIVE User Defined Functions
  • HIVE performance techniques
    • Partitioning
    • Bucketing

HBASE

  • HBase introduction
  • Architecture and schema design
  • HBase vs. RDBMS
  • Architectural components of HBase
    • HMaster
    • Region Servers
    • Regions
  • HBase commands

SQOOP

  • Introduction
  • Sqoop Commands
  • Importing data
  • Exporting Data

Flume

  • Introduction
  • Flume commands
  • Database connection
  • Importing data

PIG

  • Introduction to Pig
  • Map Reduce Vs. Apache Pig
  • Different data types in Pig
  • Modes of Execution in Pig

Oozie

  • Introduction to Oozie
  • Oozie workflow

Zookeeper

  • Introduction to Zookeeper
  • Features of Zookeeper

Spark

Scala

Who Are The Trainers?
Our trainers have relevant experience in implementing real-time solutions on different queries related to different topics. Spiritsofts verifies their technical background and expertise.
What If I Miss A Class?
We record each LIVE class session you undergo through and we will share the recordings of each session/class.
How Will I Execute The Practical?
Trainer will provide the Environment/Server Access to the students and we ensure practical real-time experience and training by providing all the utilities required for the in-depth understanding of the course.
If I Cancel My Enrollment, Will I Get The Refund?
If you are enrolled in classes and/or have paid fees, but want to cancel the registration for certain reason, it can be attained within 48 hours of initial registration. Please make a note that refunds will be processed within 30 days of prior request.
Will I Be Working On A Project?
The Training itself is Real-time Project Oriented.
Are These Classes Conducted Via Live Online Streaming?
Yes. All the training sessions are LIVE Online Streaming using either through WebEx or GoToMeeting, thus promoting one-on-one trainer student Interaction.

 

Keywords :  Big Data Jobs for Freshers, Big Data Certification Cost, Big Data Interview Questions, Big Data Analytics, Big Data Course Material, Big Data 2.0, Big Data Hadoop 2.9.0, Big Data 3.0, Big Data Latest Version Download Free, Big Data Certification Dumps, Big Data Analytics Software, Hadoop Installation, Big Data Hadoop Exam Study Guide, Big Data Testing Jobs, Big Data Training for Beginners, Big Data Tools, Big Data Placement Assistance

Is There Any Offer / Discount I Can Avail?
There are some Group discounts available if the participants are more than 2.
Who Are Our Customers?
As we are one of the leading providers of Live Instructor LED training, We have customers from USA, UK, Canada, Australia, UAE, Qatar, NZ, Singapore, Malaysia, Sydney, France, Finland, Sweden, Spain, Russia Moscow, Denmark, London, England, South Africa, Switzerland, Kenya, Philippines, Japan, Indonesia, Pakistan, Saudi Arabia,  Qatar, Kuwait, Germany, Frankfurt Berlin Munich, Poland, Belarus, Belgium Brussels Netherlands Amsterdam, India and other parts of the world.

We are located in USA. Offering Online Training in Cities like New York, New jersey, Dallas, Seattle, Baltimore, Tempe, Chandler, Scottsdale, Peoria, Honolulu, Columbus, Raleigh, Nashville, Plano, Toronto, Montreal, Calgary, Edmonton, Saint John, Vancouver, Richmond, Mississauga, Saskatoon, Kingston, Kelowna, Houston, Minneapolis, Los Angeles, San Francisco, San Jose, San Diego, Washington DC, Chicago, Philadelphia, St. Louis, Edison, Jacksonville, Towson, Salt Lake City, Davidson, Murfreesboro, Atlanta, Alexandria, Sunnyvale, Santa Clara, Carlsbad, San Marcos, Franklin, Tacoma, California, Bellevue, Austin, Charlotte, Garland, Raleigh-Cary, Boston, Orlando, Fort Lauderdale, Miami, Gilbert, Dubai, Doha, Melbourne, Brisbane, Perth, Wellington, Leeds, Manchester, Liverpool, Ireland Dublin, Oxford, Cambridge, Brighton, Cardiff, Bristol, Lithuania,  Latvia, Italy, San Marion, China Beijing, Auckland.

In India Hyderabad (Ameerpet), Kukatpally, Vizag, Nellore, Lucknow, Coimbatore, Marathahalli, Electronic city , Silk board, Kakinada, Goa, Vijayawada, Bangalore, Noida, Chennai, Kolkata, Pune, Whitefield, Mumbai, Delhi NCR,  etc…