Hadoop Interview Questions and Answers, Hadoop Interview Questions and Answers Freshers, Hadoop Interview Questions and Answers, Hadoop Interview Questions
Before getting on to the Hadoop interview questions, the student must know that the Hadoop is a continuously varying field which needs the students as well as professionals to upgrade their skills with the new features and knowledge, to get fit for the jobs associated with Hadoop. This post related to Hadoop Interview Questions and Answers, Hadoop Interview Questions and Answers Freshers, Hadoop Interview Questions and Answers, Hadoop Interview Questions will help you let out find all the solutions that are frequently asked in you upcoming Hadoop interview.
Over thousands of vacancies available for the Hadoop developers, experts must be acquaintance with all the component of Hadoop technologies. This is necessary for the students in order to have in-depth knowledge of the subject so that they can have best employment opportunities in the future. Knowing every little detail about Hadoop is the best approach to solve the problems linked with the problem.
APTRON has spent hours and hours in researching about the Hadoop Interview Questions and Answers, Hadoop Interview Questions and Answers Freshers, Hadoop Interview Questions and Answers, Hadoop Interview Questions that you might encounter in your upcoming interview. This post related to Hadoop interview questions and answers will help you let out find all the solutions that are frequently asked in you upcoming Hadoop interview. All these questions will alone help you to crack the interview and make you the best among all your competitors.
First of all, let us tell you about how the Hadoop technology is evolving in today’s world and how demanding it is in the upcoming years. In fact, according to one study, most of the companies and businesses have moved to the Hadoop and Big Data analytics. Now, you cannot predict how huge the future is going to be for the people experienced in the related technologies.
Hence, if you are looking for boosting up your profile and securing your future, Hadoop and Big Data will help you in reaching the zenith of your career. Apart from this, you would also have a lot of opportunities as a fresher.
These questions alone are omnipotent. Read and re-read the questions and their solutions to get accustomed to what you will be asked in the interview. These hadoop interview questions and answers will also help you on your way to mastering the Big Data skills and will take you to the giant world where worldwide and local businesses, huge or medium, are picking up the best and quality Big Data and Hadoop professionals.
This ultimate list of best Hadoop interview questions will ride you through the quick knowledge of the subject and topics like Hadoop, Cluster, HDFS, Pig, HBase, Hive, MapReduce. This hadoop interview questions and answers can be your next gateway to your next job as a Hadoop expert.
These are very Basic Hadoop Interview Questions and Answers for freshers and experienced both.
Q1: What is the difference between Hadoop and Traditional RDBMS?
A1: Hadoop structure works extremely well with structured and disorganized information. Hadoop will be an option in environments such as when there are requirements for BIG information processing on which the information being processed does not have constant relationships. Where the information size is too BIG for complex processing, or not simple to specify the relationships in between the information, then it ends up being tough to conserve the drawn out details in an RDBMS with a meaningful relationship.
To evaluate Internet information released by numerous sites. Considering that the direct exposure of these abilities increase, the business picking Hadoop not just for assistance managing the traditionally grown BIG information, however likewise utilizing Hadoop for satisfying high efficiency requires for brand-new applications. This will bring more awareness, however running such intricate contrast by examining big set of information takes numerous hours of processing time, and intro of Hadoop aid enhancing the computing efficiency from 10 times to 100 times or more.
RDBMS database innovation is a really tested, constant, grown and extremely supported by world finest business. This works much better when the information is meanings such as information types, relationships amongst the information, restraints and etc. This is more proper for genuine time OLTP processing.
Q2: What do the four V’s of Big Data denote?
A2: simple explanation for the four critical features of big data:
a) Volume –Scale of data
b) Velocity –Analysis of streaming data
c) Variety – Different forms of data
d) Veracity –Uncertainty of data
Q3: Name some companies that use Hadoop?
A3: These are companies who are using hadoop
- Yahoo (One of the biggest user & more than 80% code contributor to Hadoop)
Q4: What is Hadoop? Name the Main Components of a Hadoop Application?
A4: Hadoop is what developed as the option to the “Big Data” issue. Hadoop is referred to as the structure that provides a variety of tools and services in order to shop and procedure Big Data. It likewise plays an essential function in the analysis of huge information and to make effective organisation choices when it is tough to make the choice utilizing the standard technique.
Hadoop uses a large toolset that makes it possible to store and process information extremely quickly. Here are all the primary parts of the Hadoop:
- Hadoop Common
- Hadoop MapReduce
- PIG and HIVE – The Data Access Components.
- HBase – For Data Storage
- Apache Flume, Sqoop, Chukwa – The Data Integration Components
- Ambari, Oozie and ZooKeeper – Data Management and Monitoring Component
- Thrift and Avro – Data Serialization components
- Apache Mahout and Drill – Data Intelligence Components
Q5: What do you know about YARN?
A5: YARN stands for Yet Another Resource Negotiator, it is the Hadoop processing framework. YARN is responsible to manage the resources and establish an execution environment for the processes.
Q6: What does ‘jps’ command do?
A6: It gives the status of the deamons which run Hadoop cluster. It gives the output mentioning the status of namenode, datanode , secondary namenode, Jobtracker and Task tracker.
Q7: Which are the three modes in which Hadoop can be run?
A7: The three modes in which Hadoop can be run are
standalone (local) mode
Fully distributed mode
Q8: What does /etc /init.d do?
A8: /etc /init.d specifies where daemons (services) are placed or to see the status of these daemons. It is very LINUX specific, and nothing to do with Hadoop.
Q9: What if a Namenode has no data?
A9: It cannot be part of the Hadoop cluster.
Q10: What is a Namenode?
A10: Namenode is the master node on which job tracker runs and consists of the metadata. It maintains and manages the blocks which are present on the datanodes. It is a high-availability machine and single point of failure in HDFS.
Q11: What is a Secondary Namenode? Is it a substitute to the Namenode?
A11: The secondary Namenode constantly reads the data from the RAM of the Namenode and writes it into the hard disk or the file system. It is not a substitute to the Namenode, so if the Namenode fails, the entire Hadoop system goes down.
Q12: What happens if one Hadoop client renames a file or a directory containing this file while another client is still writing into it?
A12: A file will appear in the name space as soon as it is created. If a writer is writing to a file and another client renames either the file itself or any of its path components, then the original writer will get an IOException either when it finishes writing to the current block or when it closes the file.
Q13: Can Hadoop handle streaming data?
A13: Yes, through Technologies like Apache Kafka, Apache Flume, and Apache Spark it is possible to do large-scale streaming.
Q14: Why is Checkpointing Important in Hadoop?
A14: As more and more files are added the namenode creates large edit logs. Which can substantially delay NameNode startup as the NameNode reapplies all the edits. Checkpointing is a process that takes an fsimage and edit log and compacts them into a new fsimage. This way, instead of replaying a potentially unbounded 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.
Q15: What is Normalize in Bootstrap?
A15: Bootstrap uses Normalize to establish cross browser consistency.
Normalize.css is a modern, HTML5-ready alternative to CSS resets. It is a small CSS file that provides better cross-browser consistency in the default styling of HTML elements.
Q16: Why do the nodes are removed and added frequently in a Hadoop cluster?
A16: The following features of Hadoop framework makes a Hadoop administrator to add (commission) and remove (decommission) Data Nodes in a Hadoop clusters
- The Hadoop framework utilizes commodity hardware, and it is one of the important features of Hadoop framework. It results in a frequent DataNode crash in a Hadoop cluster.
- The ease of scale is yet another important feature of the Hadoop framework that is performed according to the rapid growth of data volume.
Q17: What happens when two clients try to access the same file in the HDFS?
A17: HDFS supports exclusive writes only. When the first client contacts the “NameNode” to open the file for writing, the “NameNode” grants a lease to the client to create this file. When the second client tries to open the same file for writing, the “NameNode” will notice that the lease for the file is already granted to another client, and will reject the open request for the second client.
Q18: What is bootstrap breadcrumb?
A18: Breadcrumbs are a great way to show hierarchy-based information for a site. In the case of blogs, breadcrumbs can show the dates of publishing, categories, or tags. They indicate the current page’s location within a navigational hierarchy. A breadcrumb in Bootstrap is simply an unordered list with a class of .breadcrumb. The separator is automatically added by CSS (bootstrap.min.css).
Q19: What do you know about the Speculative Execution?
A19: In Hadoop, Speculative Execution is a process that takes place during the slower execution of a task at a node. In this process, the master node starts executing another instance of that same task on the other node. And the task which is finished first is accepted and the execution of other is stopped by killing that.
Q20: What are the differences between Hadoop 1 and Hadoop 2?
A20: The following two points explain the difference between Hadoop 1 and Hadoop 2:
In Hadoop 1.X, there is a single NameNode which is thus the single point of failure whereas, in Hadoop 2.x, there are Active and Passive NameNodes. In case, the active NameNode fails, the passive NameNode replaces the active NameNode and takes the charge. As a result, high availability is there in Hadoop 2.x.
In Hadoop 2.x, the YARN provides a central resource manager that share a common resource to run multiple applications in Hadoop whereas data processing is a problem in Hadoop 1.x.
Hadoop Conclusion Interview FAQs
We know the list of Hadoop Interview Questions and Answers, Hadoop Interview Questions and Answers Freshers, Hadoop Interview Questions and Answers, Hadoop Interview Questions is overwhelming but the advantages of reading all the questions will maximize your potential and help you crack the interview. The surprising fact is that this hadoop interview questions and answers post covers all the basic of the Hadoop technology and you have to check out the FAQs of different components of hadoop too.
However, you will be asked with the questions in the interview related to the above mentioned questions. Preparing and understanding all the concept of hadoop technology will help you strengthen the other little information around the topic.
After preparing these interview questions, we recommend you to go for a mock interview before facing the real one. You can take the help of your friend or a Hadoop expert to find the loop holes in your skills and knowledge. Moreover, this will also allow you in practicing and improving the communication skill which plays a vital role in getting placed and grabbing high salaries.
Remember, in the interview, the company or the business or you can say the examiner often checks your basic knowledge of the subject. If your basics is covered and strengthened, you can have the job of your dream. The industry experts understand that if the foundation of the student is already made up, it is easy for the company to educate the employ towards advance skills. If there are no basics, there is no meaning of having learnt the subject.
Therefore, it’s never too late to edge all the basics of any technology. If you think that you’ve not acquired the enough skills, you can join our upcoming batch of Hadoop Training in Noida. We are one of the best institute for hadoop in noida which provide advance learning in the field of Hadoop Course. We’ve highly qualified professionals working with us and promise top quality education to the students.
We hope that you enjoyed reading Hadoop Interview Questions and Answers, Hadoop Interview Questions and Answers Freshers, Hadoop Interview Questions and Answers, Hadoop Interview Questions and all the FAQs associated with the interview. Do not forget to revise all the hadoop interview questions and answers before going for the hadoop and big data interview. In addition to this, if you’ve any doubt or query associated with Hadoop and Big Data, you can contact us anytime. We will be happy to help you out at our earliest convenience. At last, we wish you all the best for your upcoming interview on Hadoop Technology.