Book Image

Learning YARN

Book Image

Learning YARN

Overview of this book

Today enterprises generate huge volumes of data. In order to provide effective services and to make smarter and more intelligent decisions from these huge volumes of data, enterprises use big-data analytics. In recent years, Hadoop has been used for massive data storage and efficient distributed processing of data. The Yet Another Resource Negotiator (YARN) framework solves the design problems related to resource management faced by the Hadoop 1.x framework by providing a more scalable, efficient, flexible, and highly available resource management framework for distributed data processing. This book starts with an overview of the YARN features and explains how YARN provides a business solution for growing big data needs. You will learn to provision and manage single, as well as multi-node, Hadoop-YARN clusters in the easiest way. You will walk through the YARN administration, life cycle management, application execution, REST APIs, schedulers, security framework and so on. You will gain insights about the YARN components and features such as ResourceManager, NodeManager, ApplicationMaster, Container, Timeline Server, High Availability, Resource Localisation and so on. The book explains Hadoop-YARN commands and the configurations of components and explores topics such as High Availability, Resource Localization and Log aggregation. You will then be ready to develop your own ApplicationMaster and execute it over a Hadoop-YARN cluster. Towards the end of the book, you will learn about the security architecture and integration of YARN with big data technologies like Spark and Storm. This book promises conceptual as well as practical knowledge of resource management using YARN.
Table of Contents (20 chapters)
Learning YARN
Credits
About the Authors
Acknowledgments
About the Reviewers
www.PacktPub.com
Preface
Index

Managing the Hadoop-YARN services


The sbin Hadoop-YARN bundle contains shell scripts to manage the YARN services. It is always easy to use scripts to start or stop the services. It reads the required Hadoop configuration files, such as yarn-site.xml and slaves, in the etc/hadoop/ directory. This section will cover the usage of different scripts used by YARN.

Similar to Hadoop-HDFS scripts, YARN uses four scripts, listed and described next:

  • start-yarn.sh: The start-yarn script is used to start all the YARN daemons—ResourceManager, NodeManager on all slaves and the proxy server with a single script. It should be executed on the ResourceManager node, that is, the master node. It reads the slaves file in the configuration folder to get a list of the slaves in the YARN cluster. It creates a secure shell connection to each of the slave nodes and executes a command to start the NodeManager daemon on that node. It does not require any arguments.

  • stop-yarn.sh: The stop-yarn script is similar to the...