Hadoop is such a popular name in the Big Data domain that today, “Hadoop tutorial” has become one of the most searched terms on the Web. However, if you aren’t aware of Hadoop, it is an open-source Big Data framework designed for storing and processing massive volumes of data in distributed environments across multiple computer clusters by leveraging simple programming models.
It is designed in a way that it can scale up from single servers to hundreds and thousands of machines, each providing local storage and computation. Read: Future scope of Hadoop.
Doug Cutting and Mike Cafarella developed Hadoop. An interesting fact about Hadoop’s history is that Hadoop was named after Cutting’s kid’s toy elephant. Cutting’s kid had a yellow toy elephant named Hadoop, and that’s the origin story of the Big Data framework!
Before we dive into the Hadoop tutorial, it is essential to get the basics right. By basics, we mean Big Data.
What is Big Data?
Big Data is a term used to refer to large volumes of data, both structured and unstructured (generated daily), that’s beyond the processing capabilities of traditional data processing systems.
According to Gartner’s famous Big Data definition, it refers to the data that has a wide variety, escalates in ever-increasing volumes, and with a high velocity. Big Data can be analyzed for insights that can promote data-driven business decisions. This is where the real value of Big Data lies.
Every day, a huge amount of data is generated from various sources, including social media, digital devices, IoT, and businesses. This data must be processed to identify and deliver meaningful insights.
It denotes the rate at which organizations receive and process data. Every enterprise/organization has a specific time frame for processing data that flows in huge volumes. While some data demands real-time processing capabilities, some can be processed and analyzed as the need arises.
Since data is generated from many disparate sources, naturally, it is highly diverse and varied. While the traditional data types were mostly structured and fit well in the relational databases, Big Data comes in semi-structured and unstructured data types (text, audio, and videos, as well. Why The Need For It?
Hadoop Tutorial For Beginners
When talking about Big Data, there were three core challenges:
The first issue was where to store such colossal amounts of data? Traditional systems won’t suffice as they offer limited storage capacities.
The second issue was that Big Data is highly varied (structured, semi-structured, unstructured). So, the question arises – how to store this data that comes in diverse formats?
The final issue is the processing speed. Since Big Data comes in a large, ever-increasing volume, it was a challenge to speed up the processing time of such vast amounts of heterogeneous data.
To overcome these core challenges, Hadoop was developed. Its two primary components – HDFS and YARN are designed to help tackle the storage and processing issues. While HDFS solves the storage issue by storing the data in a distributed manner, YARN handles the processing part by reducing the processing time drastically.
Hadoop is a unique Big Data framework because:
- It features a flexible file-system that eliminates ETL bottlenecks.
- It can scale economically and deploy on commodity hardware.
- It offers the flexibility to both store and mine any type of data. Plus, it is not constrained by a single schema.
- It excels at processing complex datasets – the scale-out architecture divides workloads across many nodes.
Core Components Of Hadoop
The Hadoop cluster consists of two primary components – HDFS (Hadoop Distributed File System) and YARN (Yet Another Resource Negotiator).
HDFS is responsible for distributed storage. It features a Master-Slave topology, wherein Master is a high-end machine while Slaves are inexpensive computers. In the Hadoop architecture, the Master should be deployed on robust configuration hardware as it constitutes the center of the Hadoop cluster.
HDFS divides Big Data into several blocks, which are then stored in a distributed fashion on the cluster of slave nodes. While the Master is responsible for managing, maintaining, and monitoring the slaves, the Slaves function as the actual worker nodes. For performing tasks on a Hadoop cluster, the user has to connect with the Master node.
HDFS is further divided into two daemons:
It runs on the master machine and performs the following functions –
- It maintains, monitors, and manages DataNodes.
- It receives a heartbeat report and block reports from DataNodes.
- It captures the metadata of all the blocks in the cluster, including location, file size, permission, hierarchy, etc.
- It records all the changes made to the metadata like deletion, creation, and renaming of the files in edit logs.
It runs on the slave machines and performs the following functions –
- It stores the actual business data.
- It serves the read-write request of the users.
- It creates, deletes, replicates blocks based on the command of the NameNode.
- It sends a heartbeat report to the NameNode after every three seconds.
As mentioned earlier, YARN takes care of data processing in Hadoop. The central idea behind YARN was to split the task of resource management and job scheduling. It has two components:
- It runs on the master node.
- It tracks the heartbeats from the Node Manager.
- It has two sub-parts – Scheduler & ApplicationManager. While the Scheduler allocates resources to the running applications, the ApplicationManager acceptS job submissions and negotiates the first container for executing an application.
- It runs on individual slave machines.
- It manages containers and also monitors the resource utilization of each container.
- It sends heartbeat reports to the Resource Manager.
Hadoop Tutorial: Prerequisites to Learn Hadoop
To begin your Hadoop tutorial and be comfortable with the framework, you must have two essential prerequisites:
Be familiar with basic Linux commands
Since Hadoop is set up over Linux OS (most preferably, Ubuntu), you must be well-versed with the foundation-level Linux commands.
Be familiar with basic Java concepts
When you begin your Hadoop tutorial, you can also simultaneously start learning the basic concepts of Java, including abstractions, encapsulation, inheritance, and polymorphism, to name a few.
Features Of Hadoop
Here are the top features of Hadoop that make it popular
Hadoop is highly fault-tolerant and dependable. If ever any node goes down, it will not cause the whole cluster to fall apart – another node will replace the failed node. Thus, the Hadoop cluster can continue to function without faltering.
Hadoop is highly scalable. It can be integrated with cloud platforms that can make the framework much more scalable.
The Hadoop framework can be deployed not only on configuration hardware but also on commodity hardware (cheap machines), as well. This makes Hadoop an economical choice for small to medium-sized firms that are looking to scale.
4) Distributed Storage and Processing
Hadoop divides tasks and files into several sub-tasks and blocks, respectively. These sub-tasks and blocks function independently and are stored in a distributed manner throughout a cluster of machines.
Why Learn Hadoop?
According to a recent research report, The Hadoop Big Data Analytics market is estimated to grow from $6.71 Billion (as of 2016) to $40.69 Billion by 2021 at a CAGR of 43.4%. This only goes to show that in the coming years, the investment in Big Data will be substantial. Naturally, the demand for Big Data frameworks and technologies like Hadoop will also accelerate.
As and when that happens, the need for skilled Hadoop professionals (like Hadoop Developers, Hadoop Architects, Hadoop Administrators, etc.) will increase exponentially.
This is why now is the ideal time to learn Hadoop and acquire Hadoop skills and master Hadoop tools. In light of the significant skills gap in the demand and supply of Big Data talent, it presents a perfect scenario for more and more young aspirants to shift towards this domain.
Due to the talent shortage, companies are willing to pay hefty yearly compensation and salary packages to deserving professionals. So, if you invest your time and effort in acquiring Hadoop skills now, your career graph will definitely be upward sloping in the near future.
In conclusion: Hadoop is a technology of the future. Sure, it might not be an integral part of the curriculum, but it is and will be an integral part of the workings of an organization. So, waste no time in catching this wave; a prosperous and fulfilling career awaits you at the end of the time.
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