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

Managing the HDFS cluster


The health of HDFS is critical for a Hadoop-based Big Data platform. HDFS problems can negatively affect the efficiency of the cluster. Even worse, it can make the cluster not function properly. For example, DataNode's unavailability caused by network segmentation can lead to some under-replicated data blocks. When this happens, HDFS will automatically replicate those data blocks, which will bring a lot of overhead to the cluster and cause the cluster to be too unstable to be available for use. In this recipe, we will show commands to manage an HDFS cluster.

Getting ready

Before getting started, we assume that our Hadoop cluster has been properly configured and all the daemons are running without any problems.

Log in to the master node from the administrator machine with the following command:

ssh hduser@master

How to do it...

Use the following steps to check the status of an HDFS cluster with hadoop fsck:

  1. Check the status of the root filesystem with the following command...