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

YARN containers and resource allocations


In YARN, there are many configuration parameters, which control the memory available to AM, containers, or the total memory that can be allocated for MapReduce or JVM heap size to be used and the number of CPU cores to be used for a job. This is covered in more detail in Chapter 8, Performance Tuning, but a rough idea is to have one core for each container and each Mapper container should have a memory of about 1 GB and the Reducer should have a memory twice the size of the Mapper. In addition to this, each node must have about 20% spare for the operating system and Hadoop daemons.

Getting ready

For this recipe, you will again need a running cluster and should have completed the previous recipes to make sure the cluster is working fine in terms of HDFS and YARN.

How to do it...

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

  2. Navigate to the directory /opt/cluster/hadoop/etc/hadoop.

  3. Edit the configuration file yarn-site.xml, to make...