Dexlab, Author at DexLab Analytics | Big Data Hadoop SAS R Analytics Predictive Modeling & Excel VBA

10 Frequently-asked Hadoop Interview Questions with Answers

Posted on December 29, 2017September 22, 2018 by Dexlab

A substantial part of the Apache project, Hadoop is an open source, Java-based programming software framework that is used for storing data and running applications on different clusters of commodity hardware. Be it any kind of data, Hadoop acts as a massive storage unit backed by gargantuan processing power and an ability to tackle virtually countless tasks and jobs, simultaneously.

In this blogpost, we are going to discuss top 10 Hadoop interview questions – cracking these questions may help you bag the sexiest job of this decade.

What are the components of Hadoop?

There are 3 layers in Hadoop and they are as follows:

Storage layer (HDFS) – Also known as Hadoop Distributed File System, HDFS is responsible for storing various forms of data as blocks of information. It includes NameNode and DataNode.
Batch processing engine (MapReduce) – For parallel processing of large data sets across a standard Hadoop cluster, MapReduce is the key.
Resource management layer (YARN) – Yet Another Resource Negotiator is the powerful processing framework in Hadoop system that keeps a check on the resources.

Why is Hadoop streaming?

Hadoop distribution includes a generic application programming interface for drawing MapReduce jobs in programming languages like Ruby, Python, Perl, etc. and this is known as Hadoop streaming.

What are the different modes to run Hadoop?

Local (standalone) Mode
Pseudo-Distributed Mode
Fully-Distributed Mode

How to restart Namenode?

Begin by clicking on stop-all.sh and then on start-all.sh

Write sudo hdfs (then press enter), su-hdfs (then press enter), /etc/init.d/ha (then press enter) and finally /etc/init.d/Hadoop-0.20-name node start (then press enter).

How can you copy files between HDFS clusters?

Use multiple nodes and the distcp command to ensure smooth copying of files between HDFS clusters.

What do you mean by speculative execution in Hadoop?

In case, a node executes a task slower, the master node has the ability to start the same task on another node. As a result, the task that finishes off first will be accepted and the other one will be rejected. This entire procedure is known as “speculative execution”.

What is “WAL” in HBase?

Here, WAL stands for “Write Ahead Log (WAL)”, which is a file located in every Region Server across the distributed environment. It is mostly used to recover data sets in case of mishaps.

How to do a file system check in HDFS?

FSCK command is your to-go option to do file system check in HDFS. This command is extensively used to block locations or names or check overall health of any files.

hdfs fsck /dir/hadoop-test -files -blocks –locations

What sets apart an InputSplit from a Block?

A block divides the data, physically without taking into account the logical equations. This signifies you can posses a record that originated in one block and stretches over to another. On the other hand, InputSplit includes the logical boundaries of records, which are crucial too.

Why should you use Storm for Real-Time Processing?

Easy to operate – simple operating system makes it easy
Fast processing – it can process around 100 messages per second per node
Fault detection – it can easily detect faults and restarts functional attributes
Scores high on reliability – expect execution of each data unit at least for once
High scalability – it operates throughout clusters of machines

The article has been sourced from – www.besthadooptraining.in/blog/top-100-hadoop-interview-questions

Learn how Big Data Hadoop can help you manage your business data decisions from DexLab Analytics. We are a leading Big Data Hadoop training institute in Delhi NCR region offering industry standard big data related courses for data-aspiring candidates.

Interested in a career in Data Analyst?
To learn more about Data Analyst with Advanced excel course – Enrol Now.
To learn more about Data Analyst with R Course – Enrol Now.
To learn more about Big Data Course – Enrol Now.
To learn more about Machine Learning Using Python and Spark – Enrol Now.
To learn more about Data Analyst with SAS Course – Enrol Now.
To learn more about Data Analyst with Apache Spark Course – Enrol Now.
To learn more about Data Analyst with Market Risk Analytics and Modelling Course – Enrol Now.

Analyze the Risk of a Borrower with These Sure-fire Credit Risk Analytics Techniques

Posted on December 28, 2017February 13, 2018 by Dexlab

It’s a hard but true fact – no more do businesses survive without leverages. In a quest for success and expansion, they need to resort to debt, because equity alone fails to ensure survival. Be it funding a new project, fulfilling working capital requirement or expanding business operations, an organization needs funding for various corporate activities.

Talking of India, the credit market scenario in here is not so matured in comparison to other developed countries; hence there exists an excessive dependency level on conventional banking structure. Nevertheless, raising finance from issuance of bonds by companies is also not so rare – majority of companies in need of capital raise money from bonds and shares and this practice is widely prevalent throughout the nation.

Continue reading “Analyze the Risk of a Borrower with These Sure-fire Credit Risk Analytics Techniques”

Architecture Trade-offs Pays Well for Enterprise Analytics

Posted on December 27, 2017January 30, 2018 by Dexlab

Today, owing to an explosion of technology options, determining which analytics stack to adopt takes into account a streak of architectural trade-offs. Over the years, with our experience and expertise we have learnt the most crucial aspect of creating sound analytics systems and pleasing customers with improved digital solutions – is the location where data is to be stored and processed, and the different types of databases to use so that only the right people gain access to it.

Opt for a comprehensive data analyst course Delhi NCR from DexLab Analytics.

Continue reading “Architecture Trade-offs Pays Well for Enterprise Analytics”

Flipkart Launches a New Internal Wing AIforIndia to Bet Big on Artificial Intelligence

Posted on December 22, 2017January 30, 2018 by Dexlab

Flipkart is strengthening its base in the field of Artificial Intelligence, and so far, this year has been treating them well. After pegging fresh influx of funds, appointing a new CEO at the helm of affairs and reportedly thwarting its tailing rival, Amazon in September, Flipkart is all set to enter the most promising arena of artificial intelligence and machine learning, NOW.

In an interview to a leading daily journal, Sachin Bansal, the notable co-founder and Chairman of Flipkart is found saying – “we ready to invest hundreds of millions of dollars” in the AI gambit over the next few years. “This is the next big thing for us, where we are betting big on the use of AI and machine learning to solve problems at Flipkart. India’s problems are unique and we need to apply AI in the ecosystem to solve Indian problems. We believe that some of the focus areas for AI in developed countries cannot be applied for India. At Flipkart, we will solve problems differently because the underlying problems (in India) are different,” he states, adding that they has already started building the needed infrastructure, recruiting a dozen AI buffs and establishing partnerships with crème de la crème educational institutions, including the IITs to give a robust push to its inspiring AI initiative.

Continue reading “Flipkart Launches a New Internal Wing AIforIndia to Bet Big on Artificial Intelligence”

How to Create a Self-similar Christmas Tree Using SAS

Posted on December 21, 2017January 30, 2018 by Dexlab

The season of celebration is here! Christmas is just around the corner. And here is a beautiful self-similar Christmas tree that was created using SAS with the help of two fascinating features – matrix computations and ODS statistical graphics.

Experiencing self-similarity in Kronecker products

You might have come across blogposts highlighting how repeated Kronecker product of a binary matrix ushers us into self-similar structures. But this time, we are taking special care in introducing self-similarity in Kronecker products – like, if M is a binary matrix then Kronecker product happens to be M@M, which is a block matrix in which each 1 inside the original matrix is replaced by a copy of M, and each O is replaced with a zero block. In this blog, @ stands for the Kronecker product (or direct product) operator implemented in IML/SAS software). Continue reading “How to Create a Self-similar Christmas Tree Using SAS”

How Careers in Tech is Getting Influenced Due to CryptoCurrency Revolution

Posted on December 20, 2017January 30, 2018 by Dexlab

Cryptocurrency is the new in-thing that is creating a lot of buzz in the tech world. And though your friends and family might be hearing all good things about Bitcoin, you will be surprised to know – it’s creating job. Yes, you heard it right – cryptocurrency is exploding the job market. From startups to blue chip companies, everyone is talking about the perks of blockchain and what it potentials it holds for future.

Job trends to follow

Going by the reports uploaded by job search site Indeed, job postings for bitcoin, blockchain and cryptocurrency have increased by more than 620% since November 2015. In fact, the search ratios for such jobs have also increased by 1065%, suggesting supply is expanding along with demand.

Continue reading “How Careers in Tech is Getting Influenced Due to CryptoCurrency Revolution”

Now Navigate Through Risks with Better Data, Improved Analytics

Posted on December 19, 2017December 19, 2017 by Dexlab

The treasure trove of data can devise new improved ways to mitigate risks.

How to reduce the range of risks and better grasp the reins of the business? Though data is being gathered, and pushed through the highly advanced risk analytics tools, how do the risk insurers utilize these insights to boost improved decision-making procedures that affect the business future and potential losses?

Continue reading “Now Navigate Through Risks with Better Data, Improved Analytics”

Incredible Future Possibilities of Market Risk Analytics

Posted on December 18, 2017May 23, 2020 by Dexlab

Global risks are burgeoning; companies of all sizes are seeking the perks of risk analytics and management. Smart companies are realizing the change is coming from people as well as recent technological breakthroughs, including Big Data and AI. And CEOs are improvising their risk teams, and transforming them into perceptive strategic advisors to address budding dangerous threats like cybercrime.

Modern risk analysts have accurate knowledge about risk, artificial intelligence and cyber security – so, it’s time they get an opportunity to show a greater presence in the stoic boardrooms as strategic advisors. AI, the cutting-edge risk analytics tool surfaced out to enhance the inexorable march of big data. As such, their importance in the organization in assessing risk has greatly increased.

Continue reading “Incredible Future Possibilities of Market Risk Analytics”

Google is Back in China! It Decides to Open an AI Lab in the Far-East

Posted on December 15, 2017December 15, 2017 by Dexlab

Google is strengthening its artificial intelligence base, including China.

And it is so doing by establishing a new AI research center in Beijing. Google is digging deep into China, where it contravened the government in 2010 committing a spectacularly principled act of self-sabotage by refusing to self-censor search content and later found most of its services to be blocked. The company’s decision to return back to China is more about safeguarding its future, and acknowledging the supreme importance of technology’s most competitive field: AI.

Continue reading “Google is Back in China! It Decides to Open an AI Lab in the Far-East”

Author: Dexlab