Optimizing Hadoop for MapReduce Learn how to configure your Hadoop cluster to run optimal MapReduce jobs Khaled Tannir BIRMINGHAM - MUMBAI Optimizing Hadoop for MapReduce Copyright © 2014 Packt Publishing All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the publisher, except in the case of brief quotations embedded in critical articles or reviews. Every effort has been made in the preparation of this book to ensure the accuracy of the information presented. However, the information contained in this book is sold without warranty, either expressed or implied. Neither the author, nor Packt Publishing, and its dealers and distributors will be held liable for any damages caused or alleged to be caused directly or indirectly by this book. Packt Publishing has endeavored to provide trademark information about all of the companies and products mentioned in this book by the appropriate use of capitals. However, Packt Publishing cannot guarantee the accuracy of this information. First published: February 2014 Production Reference: 1140214 Published by Packt Publishing Ltd. Livery Place 35 Livery Street Birmingham B3 2PB, UK. ISBN 978-1-78328-565-5 www.packtpub.com Cover Image by Khaled Tannir ([email protected]) Credits Author Project Coordinator Khaled Tannir Aboli Ambardekar Reviewers Proofreaders Włodzimierz Bzyl Simran Bhogal Craig Henderson Ameesha Green Mark Kerzner Indexer Rekha Nair Acquisition Editor Joanne Fitzpatrick Graphics Yuvraj Mannari Commissioning Editor Manasi Pandire Production Coordinators Manu Joseph Technical Editors Mario D'Souza Alwin Roy Rosmy George Pramod Kumavat Cover Work Alwin Roy Arwa Manasawala Adrian Raposo Copy Editors Kirti Pai Laxmi Subramanian About the Author Khaled Tannir has been working with computers since 1980. He began programming with the legendary Sinclair Zx81 and later with Commodore home computer products (Vic 20, Commodore 64, Commodore 128D, and Amiga 500). He has a Bachelor's degree in Electronics, a Master's degree in System Information Architectures, in which he graduated with a professional thesis, and completed his education with a Master of Research degree. He is a Microsoft Certified Solution Developer (MCSD) and has more than 20 years of technical experience leading the development and implementation of software solutions and giving technical presentations. He now works as an independent IT consultant and has worked as an infrastructure engineer, senior developer, and enterprise/solution architect for many companies in France and Canada. With significant experience in Microsoft .Net, Microsoft Server Systems, and Oracle Java technologies, he has extensive skills in online/offline applications design, system conversions, and multilingual applications in both domains: Internet and Desktops. He is always researching new technologies, learning about them, and looking for new adventures in France, North America, and the Middle-east. He owns an IT and electronics laboratory with many servers, monitors, open electronic boards such as Arduino, Netduino, RaspBerry Pi, and .Net Gadgeteer, and some smartphone devices based on Windows Phone, Android, and iOS operating systems. In 2012, he contributed to the EGC 2012 (International Complex Data Mining forum at Bordeaux University, France) and presented, in a workshop session, his work on "how to optimize data distribution in a cloud computing environment". This work aims to define an approach to optimize the use of data mining algorithms such as k-means and Apriori in a cloud computing environment. He is the author of RavenDB 2.x Beginner's Guide, Packt Publishing. He aims to get a PhD in Cloud Computing and Big Data and wants to learn more and more about these technologies. He enjoys taking landscape and night time photos, travelling, playing video games, creating funny electronic gadgets with Arduino/.Net Gadgeteer, and of course, spending time with his wife and family. You can reach him at [email protected]. Acknowledgments All praise is due to Allah, the Lord of the Worlds. First, I must thank Allah for giving me the ability to think and write. Next, I would like to thank my wife, Laila, for her big support, encouragement, and patience throughout this project. Also, I would like to thank my family in Canada and Lebanon for their support during the writing of this book. I would like to thank everyone at Packt Publishing for their help and guidance, and for giving me the opportunity to share my experience and knowledge in technology with others in the Hadoop and MapReduce community. Thank you as well to the technical reviewers, who provided great feedback to ensure that every tiny technical detail was accurate and rich in content. About the Reviewers Włodzimierz Bzyl works at the University of Gdańsk, Poland. His current interests include web-related technologies and NoSQL databases. He has a passion for new technologies and introduces his students to them. He enjoys contributing to open source software and spending time trekking in the Tatra mountains. Craig Henderson graduated in 1995 with a degree in Computing for Real-time Systems and has spent his career working on large-scale data processing and distributed systems. He is the author of an open source C++ MapReduce library for single server application scalability, which is available at https://github. com/cdmh/mapreduce, and he currently researches image and video processing techniques for person identification. Mark Kerzner holds degrees in Law, Mathematics, and Computer Science. He has been designing software for many years and Hadoop-based systems since 2008. He is the President of SHMsoft, a provider of Hadoop applications for various verticals, a co-founder of the Hadoop Illuminated training and consulting, and also the co-author of the open source book, Hadoop Illuminated. He has also authored and co-authored other books and patents. I would like to acknowledge the help of my colleagues, in particular Sujee Maniyam, and last but not least, my multitalented family. www.PacktPub.com Support files, eBooks, discount offers and more You might want to visit www.PacktPub.com for support files and downloads related to your book. Did you know that Packt offers eBook versions of every book published, with PDF and ePub files available? You can upgrade to the eBook version at www.PacktPub. com and as a print book customer, you are entitled to a discount on the eBook copy. Get in touch with us at [email protected] for more details. 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Table of Contents Preface 1 Chapter 1: Understanding Hadoop MapReduce 7 The MapReduce model 7 An overview of Hadoop MapReduce 10 Hadoop MapReduce internals 10 Factors affecting the performance of MapReduce 12 Summary 14 Chapter 2: An Overview of the Hadoop Parameters 15 Investigating the Hadoop parameters 16 The mapred-site.xml configuration file 17 The CPU-related parameters 17 The disk I/O related parameters 18 The memory-related parameters 20 The network-related parameters 21 The hdfs-site.xml configuration file 22 The core-site.xml configuration file 25 Hadoop MapReduce metrics 26 Performance monitoring tools 26 Using Chukwa to monitor Hadoop 27 Using Ganglia to monitor Hadoop 27 Using Nagios to monitor Hadoop 28 Using Apache Ambari to monitor Hadoop 29 Summary 29 Chapter 3: Detecting System Bottlenecks 31 Performance tuning 32 Creating a performance baseline 33 Identifying resource bottlenecks 36 Identifying RAM bottlenecks 37