Apache ZooKeeper Essentials

Saurav Haloi

• Publisher: Packt Publishing
• Year: 2015
• eBook ISBN: 9781784391324
• Topic: Computer Science
• Subtopic: Programming in C
• Index: Computer Science

Apache ZooKeeper Essentials

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Table of Contents

Apache ZooKeeper Essentials

Credits

About the Author

About the Reviewers

www.PacktPub.com

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Why subscribe?

Free access for Packt account holders

Preface

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Downloading the example code

Errata

Piracy

Questions

1. A Crash Course in Apache ZooKeeper

Defining a distributed system

Why coordination in a distributed system is so challenging

Introducing Apache ZooKeeper

Getting hands-on with Apache ZooKeeper

Download and installation

Downloading

Installing

Configuration

Starting the ZooKeeper server

Connecting to ZooKeeper with a Java-based shell

Connecting to ZooKeeper with a C-based shell

Setting up a multinode ZooKeeper cluster

Starting the server instances

Running multiple node modes for ZooKeeper

Summary

2. Understanding the Inner Workings of Apache ZooKeeper

A top-down view of the ZooKeeper service

The ZooKeeper data model

Types of znodes

The persistent znode

The ephemeral znode

The sequential znode

Keeping an eye on znode changes – ZooKeeper Watches

The ZooKeeper operations

Watches and ZooKeeper operations

The ZooKeeper access control lists

The ZooKeeper stat structure

Understanding the inner working of ZooKeeper

The quorum mode

Client establishment of sessions with the ZooKeeper service

Implementation of ZooKeeper transactions

Phase 1 – leader election

Phase 2 – atomic broadcast

Local storage and snapshots

Summary

3. Programming with Apache ZooKeeper

Using the Java client library

Preparing your development environment

The first ZooKeeper program

Implementing a Watcher interface

Example – a cluster monitor

The C client library

Getting started with the C API

Example – the znode data watcher

Python client bindings

A watcher implementation

Summary

4. Performing Common Distributed System Tasks

ZooKeeper recipes

Barrier

Queue

Lock

Leader election

Group membership

Two-phase commit

Service discovery

Summary

5. Administering Apache ZooKeeper

Configuring a ZooKeeper server

Minimum configuration

Storage configuration

Network configuration

Configuring a ZooKeeper ensemble

Configuring a quorum

Quota and authorization

ZooKeeper best practices

Monitoring a ZooKeeper instance

Four-letter words

Java Management Extensions

Summary

6. Decorating ZooKeeper with Apache Curator

Curator components

Curator client

Curator framework

Curator recipes

Curator utilities

Curator extensions

Exhibitor

Summary

7. ZooKeeper in Action

Projects powered by ZooKeeper

Apache BookKeeper

Apache Hadoop

Apache HBase

Apache Helix

OpenStack Nova

Organizations powered by ZooKeeper

Yahoo!

Facebook

eBay

Twitter

Netflix

Zynga

Nutanix

VMware vSphere Storage Appliance

Summary

Index

Apache ZooKeeper Essentials

Copyright © 2015 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 express 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: January 2015

Production reference: 1220115

Published by Packt Publishing Ltd.

Livery Place

35 Livery Street

Birmingham B3 2PB, UK.

ISBN 978-1-78439-132-4

www.packtpub.com

Credits

Author

Saurav Haloi

Reviewers

Hanish Bansal

Christopher Tang, PhD

Commissioning Editor

Ashwin Nair

Acquisition Editor

Richard Harvey

Rebecca Youé

Content Development Editor

Ajinkya Paranjape

Technical Editor

Anushree Arun Tendulkar

Copy Editors

Karuna Narayanan

Alfida Paiva

Project Coordinator

Harshal Ved

Proofreaders

Martin Diver

Ameesha Green

Indexer

Hemangini Bari

Production Coordinator

Melwyn D'sa

Cover Work

Melwyn D'sa

About the Author

Saurav Haloi works as a principal software engineer at EMC in its data protection and availability division. With more than 10 years of experience in software engineering, he has also been associated with prestigious software firms such as Symantec Corporation and Tata Consultancy Services, where he worked in the design and development of complex, large-scale, multiplatform, multi-tier, and enterprise software systems in a storage, networking, and distributed systems domain. He has been using Apache ZooKeeper since 2011 in a variety of different contexts. He graduated from National Institute of Technology, Surathkal, India, with a bachelors degree in computer engineering. An open source enthusiast and a hard rock and heavy metal fanatic, he lives in the city of Pune in India, which is also known as the Oxford of the East.

I would like to thank my family for their support and encouragement throughout the writing of this book.

It was a pleasure to work with Packt Publishing, and I would like to thank everyone associated with this book: the editors, reviewers, and project coordinators, for their valuable comments, suggestions, and assistance during the book development period. Special thanks to Ajinkya Paranjape, my content development editor, who relentlessly helped me while writing this book and patiently answered all my queries relating to the editorial processes.

I would also like to thank the Apache ZooKeeper contributors, committers, and the whole community for developing such a fantastic piece of software and for their continuous effort in getting ZooKeeper to the shape it is in now. Kudos to all of you!

About the Reviewers

Hanish Bansal is a software engineer with over 3 years of experience in developing Big Data applications. He has worked on various technologies such as the Spring framework, Hibernate, Hadoop, Hive, Flume, Kafka, Storm, and NoSQL database...

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• Apache ZooKeeper Essentials