Book Image

Hadoop 2.x Administration Cookbook

By : Aman Singh
Book Image

Hadoop 2.x Administration Cookbook

By: Aman Singh

Overview of this book

Hadoop enables the distributed storage and processing of large datasets across clusters of computers. Learning how to administer Hadoop is crucial to exploit its unique features. With this book, you will be able to overcome common problems encountered in Hadoop administration. The book begins with laying the foundation by showing you the steps needed to set up a Hadoop cluster and its various nodes. You will get a better understanding of how to maintain Hadoop cluster, especially on the HDFS layer and using YARN and MapReduce. Further on, you will explore durability and high availability of a Hadoop cluster. You’ll get a better understanding of the schedulers in Hadoop and how to configure and use them for your tasks. You will also get hands-on experience with the backup and recovery options and the performance tuning aspects of Hadoop. Finally, you will get a better understanding of troubleshooting, diagnostics, and best practices in Hadoop administration. By the end of this book, you will have a proper understanding of working with Hadoop clusters and will also be able to secure, encrypt it, and configure auditing for your Hadoop clusters.
Table of Contents (20 chapters)
Hadoop 2.x Administration Cookbook
Credits
About the Author
About the Reviewers
www.PacktPub.com
Customer Feedback
Preface
Index

ZooKeeper configuration


In a distributed system, it is important to keep things coordinated and in sync with each other. In a cluster, if we have more than one master, so there should be a mechanism to control who should be the leader or decision maker and can make changes or writes to metadata, and who are just readers or have read-only access.

To do this, we need a co-ordination service that can do all of this, for which we will use the ZooKeeper service.

Getting ready

Before going through the recipe in this section, we need at least one node to install ZooKeeper. This could be a dedicated node or it can be co-located with other nodes in the cluster. In production, ZooKeeper is configured to run on minimum three nodes, which makes it highly available and there must always be odd number of nodes in the ZooKeeper quorum.

Mostly, ZooKeeper nodes are co-located with master nodes in the cluster. Never run them on slave nodes as they will be replaced often due to Datanode failures. In this recipe...