Book Image

Mastering Hadoop

By : Karanth
Book Image

Mastering Hadoop

By: Karanth

Overview of this book

Do you want to broaden your Hadoop skill set and take your knowledge to the next level? Do you wish to enhance your knowledge of Hadoop to solve challenging data processing problems? Are your Hadoop jobs, Pig scripts, or Hive queries not working as fast as you intend? Are you looking to understand the benefits of upgrading Hadoop? If the answer is yes to any of these, this book is for you. It assumes novice-level familiarity with Hadoop.
Table of Contents (15 chapters)
14
Index

YARN commands


Like Hadoop, YARN has a script that provides commands to manage YARN. The commands are of the following two kinds:

  • User commands: These are commands for the cluster user

  • Administration commands: These are commands for the cluster administrator

In Hadoop deployment, the YARN script is found in the same directory as the Hadoop scripts. The general syntax of the YARN script is as follows:

yarn [--config <config directory>] command [options]

The –config option can be used to override the default configuration. The default configuration directory is picked up from the environment variable $HADOOP_PREFIX/conf.

User commands

The following are the important user commands in YARN:

  • The jar command is used to run a custom, user-built JAR file. In the previous distributed shell example, we use the following command to run the YARN job. The syntax for the command is:

    yarn jar <jar file path> [main class name] [arguments…]
    
  • The application command is used to manipulate a running...