A comprehensive guide to Hadoop architecture – understanding the nuts and bolts – IQCode

Hadoop Architecture: A Comprehensive Guide

Hadoop is an open-source technology that has come a long way since its inception. In this guide, we will cover the history, components, and architecture of Hadoop.

History of Hadoop
Hadoop was first created in 2005 by Doug Cutting and Mike Cafarella. Its name is derived from a toy elephant that belonged to Cutting’s son. It was originally created to support the Apache Nutch search engine project, but quickly grew in popularity and became its own project.

What is Hadoop?
Hadoop is a distributed computing platform designed to handle large volumes of data across many commodity servers. It is designed to be highly resilient to server failures and can scale horizontally to handle petabytes of data.

Components of Hadoop
Hadoop is made up of several components, including HDFS for distributed storage, MapReduce for distributed processing, and Yarn for resource management.

Hadoop Architecture
The Hadoop architecture is designed to support large-scale data processing. It is based on a master/slave architecture, where the master node oversees the entire system and the slave nodes perform the actual data processing.

Advantages of Hadoop Architecture
Owning your own hardware and implementing a Hadoop architecture can lead to cost savings, optimized performance, and greater scalability.

Disadvantages of Hadoop Architecture
Hadoop requires significant technical expertise and can be complex to set up and maintain.

Useful Resources
To learn more about Hadoop architecture and best practices, check out the following resources:

– Hadoop: The Definitive Guide by Tom White
– Apache Hadoop Official Documentation
– Hortonworks Hadoop Tutorials


Hadoop, a software framework for data processing, was first developed by Google in the late 2000s and released in 2009. It serves as an open source alternative to the proprietary Hadoop software used by companies such as Yahoo and Facebook. Hadoop can store and process vast amounts of data from various sources such as social media, websites, and sensors, and it can analyze big datasets. Its scalable and adaptable design makes it appropriate for a wide range of uses such as online services and large-scale data centres. Although Hadoop was originally created for storing and processing significant data, it has evolved to support other purposes like analysis and storage.

What is Hadoop?

Hadoop is a software framework used for storing and analyzing large amounts of data. Originally created by Google, it’s now widely used by many companies. Hadoop is useful for data scientists as it offers secure and efficient ways of storing and analyzing large amounts of data. It’s also more efficient than traditional methods for companies to store and analyze their data.

Components of Hadoop

The diagram shows how Hadoop interacts with other components in the ecosystem.

– HDFS: This open-source solution is used for Hadoop file storage and is scalable, optimized for high volumes of read-intensive data, and includes built-in analytics. It is a popular solution for large-scale data analysis.

– YARN: This resource scheduler is responsible for determining resource allocation and availability.

– MapReduce: This data processing technique allows efficient and effective processing of large datasets. It is useful for tasks such as data mining, analysis, and machine learning.

– Hadoop Common: This open-source, distributed computing platform is used for storing and analyzing data from various sources, including databases, web servers, and file systems. It allows for faster data processing through distributed computing.

Hadoop Architecture

Hadoop is an open-source, distributed computing platform that can scale to handle large amounts of data from various sources, including databases, web servers, and file systems. By distributing data processing across many computers, Hadoop processes data much faster than traditional methods.HDFS: A Scalable Solution for Data Warehousing and Analysis

Namenode and Datanode:
The Namenode running on the master server executes the lookup and returns a list of matching records. DataNodes use data blocks to store different data types. If a DataNode fails, the client gets the latest list of data blocks from the Namenode and communicates with the DataNode that has the latest data block. DataNode is recommended to be small and as close as possible to the data’s center. The same version of Java should be used in a distributed system.

Block in HDFS:
The default block size is 128 MB or 256 MB. The block size should be chosen wisely to avoid excessive metadata growth. HDFS has the option of keeping the metadata as large as possible.

Replication Management:
The NameNode tracks each data node’s block report and adds or removes replicas when a block is under or over-replicated. A proper backup and restoration mechanism should be in place for highly available data storage.

Rack Awareness:
When a block is deleted from a rack, the next available block will be placed on the same rack. The rack awareness algorithm alerts other storage nodes to take over a failed node’s responsibility. HDFS provides high-speed data access to its users through distributed data store architecture, allowing for parallel processing of data in multiple data nodes.

Understanding MapReduce for Efficient Data Processing

MapReduce is a software framework that enables efficient processing of large volumes of data, especially in real-time and streaming applications. It works by dividing data into partitions that are then processed through multiple map and reduce functions.

In a MapReduce job, the map function generates, parses, transforms and filters data before passing it on to the reduce function. The reduce function, on the other hand, groups, aggregates, and partitions intermediate data from the map functions to generate a result.

The output of both map and reduce functions is similar, but the former generates a report while the latter returns a data structure that can be further analyzed. Map tasks are usually run on the same node as the input source, and they are triggered when the data volume becomes too large to be processed within a short period of time.

Overall, MapReduce helps to achieve efficient data processing, making it a great tool for data-intensive applications.

YARN: A Resource Management and Job Scheduling/Monitoring Tool

YARN, also known as Yet Another Resource Negotiator, is an essential tool in Hadoop for managing resources and job scheduling/monitoring. It acts as a global ResourceManager for the YARN network, isolating resource management from job scheduling and monitoring. YARN manages resources for all applications and oversees per-application ApplicationMaster, which communicates with the ResourceManager and NodeManager to manage and monitor resource usage. Resources include CPU, memory, disk, and connectivity.Advantages of Hadoop Architecture


Hadoop is a distributed storage and processing framework used by several businesses to run applications, process data on thousands of nodes, and access single data sources such as social media.

**Advantages of Hadoop**

1. Scalability: Hadoop can store and distribute large data sets across hundreds of servers for processing large amounts of data. Unlike RDBMS, Hadoop provides a cost-effective solution for businesses to process thousands of terabytes of data.

2. Data Variety: Hadoop allows businesses to access a wide variety of structured and unstructured data types, providing business insights from sources such as social media and email communications. Hadoop can be used for log processing, data warehousing, fraud detection, and more.

3. Reduced Storage Costs: Hadoop reduces storage costs by mapping data wherever it’s located in the cluster. The tools for data processing are often on the same servers where data is saved. Large volumes of unstructured data can be processed efficiently using Hadoop in a few hours or minutes.

4. Fault Tolerance: Hadoop offers fault tolerance by duplicating data to other nodes when transferred to an individual node in the cluster. When a node fails, there is another copy available to use.

In conclusion, Hadoop architecture provides solutions for businesses with exploding data sets to process large amounts of data across several inexpensive servers. By accessing different types of data, businesses can gain new insights and find solutions for several purposes.

Disadvantages of Hadoop Architecture

Hadoop architecture is complex and difficult to manage, especially for security. Encryption is lacking at the storage and network levels, making it at risk for cybercriminals and other miscreants. The Hadoop Distributed File System cannot efficiently handle small files. It is necessary to run the latest stable version of Hadoop or to use a third-party vendor that can address these issues. Companies may need to use additional platforms to improve data collection, aggregation, and integration to gain more significant benefits.

Hadoop: A Flexible Software Framework for Scalable Data Processing

Hadoop is a versatile and user-friendly software framework that stores and processes vast amounts of data from various sources like databases, web services, and batch files with ease. It has revolutionized data warehousing, Big Data analytics and cloud computing with its scalability. The core function of Hadoop is the MapReduce framework, which breaks down tasks into smaller parts and then consolidates them. Hadoop also utilizes HDFS, a distributed file system that is efficient in storing data on multiple machines. Hadoop is flexible, and can be used in the cloud, on-premise installations, or in data centers while still being user-friendly.

Helpful Resources

Here are some useful resources related to Hadoop:

- Hadoop Interview Questions
- Features of Hadoop
- HDFS Architecture
- YARN Architecture
- Hive Architecture

Please note that these resources are for informational purposes only and do not act as an API.

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