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

Configuring rack awareness


There will always be failures in clusters, such as hardware issues with servers, racks, switches, power supplies, and so on.

To make sure that there is no single point of failure across the entire Hadoop infrastructure, and to ensure that the contention of resources is in a distributed manner, rack awareness plays an important role. Rack awareness is a concept in which Namenode is made aware of the layout of servers in a cluster, thus making intelligent decisions on block placement.

Getting ready

For the following steps, we assume that the cluster that is up and running with Datanodes is in a healthy state. We will log in to the Namenode and make changes there.

How to do it...

  1. ssh to Namenode and edit the hdfs-site.xml file to add the following property to it:

    <property>
    <name>topology.script.file.name</name>
    <value>/opt/cluster/topology.sh</value>
    </property>
  2. Make sure that the topology.sh file is readable by the user hadoop.

  3. Create...