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 YARN history server


Whenever a MapReduce job runs, it launches containers on multiple nodes and the logs for that container are only written on that particular node. If the user needs details of the job, he needs to go to all the nodes to fetch the logs, which could be very tedious in large clusters.

A better approach will be to aggregate the logs at a common location once the job finishes and then it can be accessed using a web server or other means. To address this, History Server was introduced in Hadoop, to aggregate logs and provide a Web UI, for users to see logs for all the containers of a job at one place.

Getting ready

You need to have a running cluster with YARN set up and should have completed the previous recipe to make sure the cluster is working fine in terms of HDFS and YARN.

The following steps will guide you through the process of setting up Job history server.

How to do it...

  1. Connect to the ResourceManager node, which is the YARN master and switch to user hadoop.

  2. Navigate...