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

Using HDFS Image Viewer


It is important to understand how metadata of the Namenode is stored and what changes to the filesystem have been rolled into fsimage file. The fsimage file and edits file cannot be viewed using a cat or vi editor, but needs specialized tools to do so.

Hadoop, by default, comes with utilities to view the fsimage file and edits file and, in this recipe, we will cover how to use these tools.

Getting ready

To step through the recipe in this section, we need a Hadoop cluster set up and running. The reader is encouraged to understand the Namenode metadata and its location.

How to do it...

  1. Connect to master1.cyrus.com master node in the cluster and switch to user hadoop.

  2. Confirm the location of the Namenode metadata by looking into hdfs-site.xml file. There will be something similar to the following, which points to the location of metadata. We will see in a later recipe how to check the value of any parameter, without opening the configuration files. To know the location of...