Book Image

Hadoop Operations and Cluster Management Cookbook

By : Shumin Guo
Book Image

Hadoop Operations and Cluster Management Cookbook

By: Shumin Guo

Overview of this book

<p>We are facing an avalanche of data. The unstructured data we gather can contain many insights that could hold the key to business success or failure. Harnessing the ability to analyze and process this data with Hadoop is one of the most highly sought after skills in today's job market. Hadoop, by combining the computing and storage powers of a large number of commodity machines, solves this problem in an elegant way!</p> <p>Hadoop Operations and Cluster Management Cookbook is a practical and hands-on guide for designing and managing a Hadoop cluster. It will help you understand how Hadoop works and guide you through cluster management tasks.</p> <p>This book explains real-world, big data problems and the features of Hadoop that enables it to handle such problems. It breaks down the mystery of a Hadoop cluster and will guide you through a number of clear, practical recipes that will help you to manage a Hadoop cluster.</p> <p>We will start by installing and configuring a Hadoop cluster, while explaining hardware selection and networking considerations. We will also cover the topic of securing a Hadoop cluster with Kerberos, configuring cluster high availability and monitoring a cluster. And if you want to know how to build a Hadoop cluster on the Amazon EC2 cloud, then this is a book for you.</p>
Table of Contents (15 chapters)
Hadoop Operations and Cluster Management Cookbook
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Configuring HDFS federation


Hadoop NameNode keeps the metadata in the main memory. When the HDFS namespace becomes large, the main memory can become a bottleneck of the cluster. HDFS federation was introduced in Hadoop for MRv2. It increases the NameNode capacity and throughput by leveraging the capacity of multiple independent NameNodes, with each NameNode hosting or managing part of the HDFS namespace.

Getting ready

Currently, only Hadoop MRv2 supports NameNode federation, so we are assuming that Hadoop MRv2 has been properly configured on all the cluster machines.

Note

We are assuming that all the configurations are making changes to the $HADOOP_CONF_DIR/hdfs-site.xml file.

How to do it...

Use the following steps to configure HDFS federation:

  1. Log in to master1 with the following command:

    ssh hduser@master1
    
  2. Specify a list of NameNode service IDs by adding the following lines into the file:

    <property>
      <name>dfs.nameservices</name>
      <value>namenode1,namenode2</value...