Conventions

In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning. Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "Add the following line in the storm.yaml file of the Nimbus machine to enable JMX on the Nimbus node."

A block of code is set as follows:

<dependency>
  <groupId>org.apache.storm</groupId>
  <artifactId>storm-core</artifactId>
  <version>1.0.2</version>
  <scope>provided<scope>
</dependency>

Any command-line input or output is written as follows:

cd $ZK_HOME/conf
touch zoo.cfg

New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: "Now, click on the Connect button to view the metrics of the supervisor node."