Learning Hadoop 2

Conventions

In this book, you will find a number of styles of text 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: "If Avro dependencies are not present in the classpath, we need to add the Avro MapReduce.jar file to our environment before accessing individual fields."

A block of code is set as follows:

topic_edges_grouped = FOREACH topic_edges_grouped {
  GENERATE
    group.topic_id as topic,
    group.source_id as source,
    topic_edges.(destination_id,w) as edges;
}

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