Apache Hadoop YARN Install Quick Start
Apache Hadoop presents the user with a vast ecosystem of tools and applications. For those familiar with Hadoop version 1, there are two core components; the Hadoop Distributed File System and the integrated MapReduce distributed processing engine. Hadoop YARN is the new replacement for the monolithic MapReduce component found in version 1. The scheduling and resource management have been separated from the management of MapReduce pipelines. While Hadoop version 2 with YARN still provides full MapReduce capability and backwards compatibility with version 1, it also opens the door to many other “application frameworks” that are not based on MapReduce processing.
The acronym YARN is short for “Yet Another Resource Negotiator,” which is a good description of what YARN actually does. Fundamentally, YARN is a resource scheduler designed to work on existing and new Hadoop clusters. The seemingly trivial split of resource scheduling from the MapReduce data flow opens up a whole new range of possibilities for Hadoop and Big Data processing. A separate scheduler allows for better utilization and scalability of the cluster, while simultaneously providing a platform for other non-MapReduce applications to take advantage of the Hadoop Distributed File System and run-time environment. A more detailed discussion of the new Hadoop YARN capabilities can be found in Chapter 3, “Apache Hadoop YARN Core Concepts.”
From a larger vantage point, YARN can be viewed as a cluster-wide Operating System that provides the essential services for applications to take advantage of a large dynamic and parallel resource infrastructure. Applications written in any language can now take advantage of the combined Hadoop compute and storage assets within any size cluster.
Although motivated by the needs of large clusters, YARN is capable of running on a single cluster node or desktop machine. The instructions in this chapter will allow you to install and explore Apache Hadoop version 2 with YARN on a single machine.
A production Apache Hadoop system can take time to set up properly and is not necessary to start experimenting with many of the YARN concepts and attributes. This chapter provides a quick start guide to installing Hadoop version Hadoop 2.2.0 on a single machine (workstation, server, or a laptop).
A more complete description of other installation options, such as those required by a production cluster setup, is given in Chapter 5, “Installing Apache Hadoop YARN.” Before we begin with the quick start, we will mention a few background details that will help with installation. These items include rudimentary knowledge of Linux, package installation, and basic system administration commands.
A basic Apache Hadoop version 2 system has two core components:
- The Hadoop Distributed File System (HDFS) for storing data
- Hadoop YARN for implementing applications to process data
Other Apache Hadoop components, such as Pig and Hive, can be added after the two core components are installed and operating properly.