Conventions used

There are a number of text conventions used throughout this book.

CodeInText: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: "Mount the downloaded WebStorm-10*.dmg disk image file as another disk in your system."

A block of code is set as follows:

val spark = SparkSession
     .builder
       .appName("StructuredNetworkWordCount")
       .master(master)
       .getOrCreate()

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

-------------------------------------------
 Time: 1527457655000 ms
 -------------------------------------------
 (consumer,1)
 (Yet,1)
 (another,1)
 (message,2)
 (for,1)
 (the,1)

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

$KAFKA_HOME/bin/kafka-server-start.sh $KAFKA_HOME/config/server.properties

Bold: Indicates a new term, an important word, or words that you see onscreen. For example, words in menus or dialog boxes appear in the text like this. Here is an example: "Select System info from the Administration panel."