Welcome!

SDN Journal Authors: Liz McMillan, Elizabeth White, Yeshim Deniz, Pat Romanski, TJ Randall

Related Topics: @DXWorldExpo, Java IoT, Open Source Cloud, @CloudExpo, Apache, SDN Journal

@DXWorldExpo: Article

The Components of Apache Hadoop

A technical description of the projects that comprise Hadoop

What is Hadoop?
Following my high-level write-up of Hadoop and Big Data, this article will present each of the components or projects that make up Hadoop with a technical description of each.

First, what is Hadoop?

Hadoop stores and processes large volumes of a wide variety of data that changes rapidly. It analyses and summarizes the data. For example: census of a city, web page analytics, threat analysis, risk models, network failures, etc.

Hadoop is redundant and reliable, powerful and focused on batch processing.

Hadoop divides a large data processing job into many smaller tasks that can be distributed across all the nodes

Hadoop comprises two main components:

  • MapReduce: The task to analyse the data and summarize the results
  • HDFS: The distributed file system, on commodity server hardware, that contains the data.

On each server there is a task tracker and a data node:

DataNode
The data node stores the data in HDFS and keeps track of access to the data.

TaskTracker
Task tracker launches a map reduce job on a node and manages the many tasks within one MapReduce job. So if my project was to conduct a census count, task tracker may count the members of a household on a data node. When finshed, task tracker reports its status to the job tracker. (Note: as of this writing, May 2013, TaskTracker is being obsoleted and replaced by "Yarn" in MapReduce v2.

JobTracker
Job tracker keeps track of all the jobs being executed and tries to schedule each map job as close to the actual data being processed. If a task has failed or disappeared perhaps due to hardware failure, job tracker will assign that task to another node.

So, now that I know what is a task and job how do I write tasks? How does a user create a map reduce job? There are various projects that make it easy. (As to how the projects were named, don't ask me!)

Apache Pig
To write a computer program, a software engineer might use a compiler, like "C",  that compiles 'pseudo english instructions (IF, THEN, FOR, ELSE) and creates machine code that a computer an execute. Similarly, Apache Pig is a high level language that expresses data map reduce jobs and translates them to JAVA computer language. Pig's primary feature is that it can be run in parallel, meaning many map reduce jobs can run simultaneously to allow linear scaling and efficiency.

Apache Hive
Hive is a SQL like language, HiveQL, which allows you to define computation in SQL like language and then and translate it down into map reduce JAVA code. Hive also allows traditional MapRedce programmers to plug in their custom MapReducers when it is  inefficient to express their logic in HiveQL.

hBase
hBase is a simple interface to distributed data that allows incremental processing. hBase stores its information in HDFS and metadata in zookeeper.

hCatalog
hCatalog is an abstraction layer for referencing data without using the underlying file­names or formats. It insulates users and scripts from how and where the data is physically stored.

Some of the smaller projects

Mahout
Mahout is a machine learning library to write MapReduce applications focused on machine learning

Ambari, Gagli and Nagios
These projects help you understand what goes on in your cluster

Scoop
Scoop is a tool that lets you run map reduce applications to or from sql databases

Oozie
Oozie is a workflow that triggers MapReduce jobs and executes them automatically or launches when new data becomes available.

Flume
Streams inputs into hadoop and gets that data loaded into hdfs

Here is a graphical view of the components

Hadoop components, courtesy of Hortonworks

(courtesy of Hortonworks)

More Stories By Jonathan Gershater

Jonathan Gershater has lived and worked in Silicon Valley since 1996, primarily doing system and sales engineering specializing in: Web Applications, Identity and Security. At Red Hat, he provides Technical Marketing for Virtualization and Cloud. Prior to joining Red Hat, Jonathan worked at 3Com, Entrust (by acquisition) two startups, Sun Microsystems and Trend Micro.

(The views expressed in this blog are entirely mine and do not represent my employer - Jonathan).

@CloudExpo Stories
HyperConvergence came to market with the objective of being simple, flexible and to help drive down operating expenses. It reduced the footprint by bundling the compute/storage/network into one box. This brought a new set of challenges as the HyperConverged vendors are very focused on their own proprietary building blocks. If you want to scale in a certain way, let's say you identified a need for more storage and want to add a device that is not sold by the HyperConverged vendor, forget about it...
In his keynote at 19th Cloud Expo, Sheng Liang, co-founder and CEO of Rancher Labs, discussed the technological advances and new business opportunities created by the rapid adoption of containers. With the success of Amazon Web Services (AWS) and various open source technologies used to build private clouds, cloud computing has become an essential component of IT strategy. However, users continue to face challenges in implementing clouds, as older technologies evolve and newer ones like Docker c...
"MobiDev is a software development company and we do complex, custom software development for everybody from entrepreneurs to large enterprises," explained Alan Winters, U.S. Head of Business Development at MobiDev, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
22nd International Cloud Expo, taking place June 5-7, 2018, at the Javits Center in New York City, NY, and co-located with the 1st DXWorld Expo will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud ...
The next XaaS is CICDaaS. Why? Because CICD saves developers a huge amount of time. CD is an especially great option for projects that require multiple and frequent contributions to be integrated. But… securing CICD best practices is an emerging, essential, yet little understood practice for DevOps teams and their Cloud Service Providers. The only way to get CICD to work in a highly secure environment takes collaboration, patience and persistence. Building CICD in the cloud requires rigorous ar...
@DevOpsSummit at Cloud Expo, taking place November 12-13 in New York City, NY, is co-located with 22nd international CloudEXPO | first international DXWorldEXPO and will feature technical sessions from a rock star conference faculty and the leading industry players in the world.
"We're focused on how to get some of the attributes that you would expect from an Amazon, Azure, Google, and doing that on-prem. We believe today that you can actually get those types of things done with certain architectures available in the market today," explained Steve Conner, VP of Sales at Cloudistics, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
Sanjeev Sharma Joins November 11-13, 2018 @DevOpsSummit at @CloudEXPO New York Faculty. Sanjeev Sharma is an internationally known DevOps and Cloud Transformation thought leader, technology executive, and author. Sanjeev's industry experience includes tenures as CTO, Technical Sales leader, and Cloud Architect leader. As an IBM Distinguished Engineer, Sanjeev is recognized at the highest levels of IBM's core of technical leaders.
As Cybric's Chief Technology Officer, Mike D. Kail is responsible for the strategic vision and technical direction of the platform. Prior to founding Cybric, Mike was Yahoo's CIO and SVP of Infrastructure, where he led the IT and Data Center functions for the company. He has more than 24 years of IT Operations experience with a focus on highly-scalable architectures.
JETRO showcased Japan Digital Transformation Pavilion at SYS-CON's 21st International Cloud Expo® at the Santa Clara Convention Center in Santa Clara, CA. The Japan External Trade Organization (JETRO) is a non-profit organization that provides business support services to companies expanding to Japan. With the support of JETRO's dedicated staff, clients can incorporate their business; receive visa, immigration, and HR support; find dedicated office space; identify local government subsidies; get...
Dion Hinchcliffe is an internationally recognized digital expert, bestselling book author, frequent keynote speaker, analyst, futurist, and transformation expert based in Washington, DC. He is currently Chief Strategy Officer at the industry-leading digital strategy and online community solutions firm, 7Summits.
Bill Schmarzo, author of "Big Data: Understanding How Data Powers Big Business" and "Big Data MBA: Driving Business Strategies with Data Science," is responsible for setting the strategy and defining the Big Data service offerings and capabilities for EMC Global Services Big Data Practice. As the CTO for the Big Data Practice, he is responsible for working with organizations to help them identify where and how to start their big data journeys. He's written several white papers, is an avid blogge...
DXWorldEXPO LLC announced today that Dez Blanchfield joined the faculty of CloudEXPO's "10-Year Anniversary Event" which will take place on November 11-13, 2018 in New York City. Dez is a strategic leader in business and digital transformation with 25 years of experience in the IT and telecommunications industries developing strategies and implementing business initiatives. He has a breadth of expertise spanning technologies such as cloud computing, big data and analytics, cognitive computing, m...
In past @ThingsExpo presentations, Joseph di Paolantonio has explored how various Internet of Things (IoT) and data management and analytics (DMA) solution spaces will come together as sensor analytics ecosystems. This year, in his session at @ThingsExpo, Joseph di Paolantonio from DataArchon, added the numerous Transportation areas, from autonomous vehicles to “Uber for containers.” While IoT data in any one area of Transportation will have a huge impact in that area, combining sensor analytic...
Bill Schmarzo, author of "Big Data: Understanding How Data Powers Big Business" and "Big Data MBA: Driving Business Strategies with Data Science," is responsible for setting the strategy and defining the Big Data service offerings and capabilities for EMC Global Services Big Data Practice. As the CTO for the Big Data Practice, he is responsible for working with organizations to help them identify where and how to start their big data journeys. He's written several white papers, is an avid blogge...
Charles Araujo is an industry analyst, internationally recognized authority on the Digital Enterprise and author of The Quantum Age of IT: Why Everything You Know About IT is About to Change. As Principal Analyst with Intellyx, he writes, speaks and advises organizations on how to navigate through this time of disruption. He is also the founder of The Institute for Digital Transformation and a sought after keynote speaker. He has been a regular contributor to both InformationWeek and CIO Insight...
Michael Maximilien, better known as max or Dr. Max, is a computer scientist with IBM. At IBM Research Triangle Park, he was a principal engineer for the worldwide industry point-of-sale standard: JavaPOS. At IBM Research, some highlights include pioneering research on semantic Web services, mashups, and cloud computing, and platform-as-a-service. He joined the IBM Cloud Labs in 2014 and works closely with Pivotal Inc., to help make the Cloud Found the best PaaS.
It is of utmost importance for the future success of WebRTC to ensure that interoperability is operational between web browsers and any WebRTC-compliant client. To be guaranteed as operational and effective, interoperability must be tested extensively by establishing WebRTC data and media connections between different web browsers running on different devices and operating systems. In his session at WebRTC Summit at @ThingsExpo, Dr. Alex Gouaillard, CEO and Founder of CoSMo Software, presented ...
In a world where the internet rules all, where 94% of business buyers conduct online research, and where e-commerce sales are poised to fall between $427 billion and $443 billion by the end of this year, we think it's safe to say that your website is a vital part of your business strategy. Whether you're a B2B company, a local business, or an e-commerce site, digital presence is key to maintain in your drive towards success. Digital Performance will take priority in 2018 for the following reason...
I think DevOps is now a rambunctious teenager - it's starting to get a mind of its own, wanting to get its own things but it still needs some adult supervision," explained Thomas Hooker, VP of marketing at CollabNet, in this SYS-CON.tv interview at DevOps Summit at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
What's the role of an IT self-service portal when you get to continuous delivery and Infrastructure as Code? This general session showed how to create the continuous delivery culture and eight accelerators for leading the change. Don Demcsak is a DevOps and Cloud Native Modernization Principal for Dell EMC based out of New Jersey. He is a former, long time, Microsoft Most Valuable Professional, specializing in building and architecting Application Delivery Pipelines for hybrid legacy, and cloud ...