Book Image

Learning YARN

By : Akhil Arora, Shrey Mehrotra, Shreyank Gupta
Book Image

Learning YARN

By: Akhil Arora, Shrey Mehrotra, Shreyank Gupta

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
About the Authors
About the Reviewers

Understanding NodeManager

The NodeManager node is the worker node for YARN and is responsible for updating the resource availability on a node to ResourceManager. It is also responsible for monitoring the health of a node and for executing containers for an application.

The following diagram shows various subcomponents of the NodeManager daemon followed by a detailed description of these subcomponents:

Status updates

The resource capability of a cluster is calculated as the sum of the capabilities of all NodeManager nodes. To utilize cluster resources efficiently, it is important to keep track of all resources across the cluster. NodeManager nodes send regular status updates to the ResourceManager. This enables ResourceManager to schedule execution of applications efficiently and increases the cluster performance. Few of the classes defined in the NodeManager framework for sending updates are mentioned in the upcoming sections.

  1. NodeStatusUpdater

    Every slave node with the NodeManager daemon registers...