Book Image

Hadoop Beginner's Guide

Book Image

Hadoop Beginner's Guide

Overview of this book

Data is arriving faster than you can process it and the overall volumes keep growing at a rate that keeps you awake at night. Hadoop can help you tame the data beast. Effective use of Hadoop however requires a mixture of programming, design, and system administration skills."Hadoop Beginner's Guide" removes the mystery from Hadoop, presenting Hadoop and related technologies with a focus on building working systems and getting the job done, using cloud services to do so when it makes sense. From basic concepts and initial setup through developing applications and keeping the system running as the data grows, the book gives the understanding needed to effectively use Hadoop to solve real world problems.Starting with the basics of installing and configuring Hadoop, the book explains how to develop applications, maintain the system, and how to use additional products to integrate with other systems.While learning different ways to develop applications to run on Hadoop the book also covers tools such as Hive, Sqoop, and Flume that show how Hadoop can be integrated with relational databases and log collection.In addition to examples on Hadoop clusters on Ubuntu uses of cloud services such as Amazon, EC2 and Elastic MapReduce are covered.
Table of Contents (19 chapters)
Hadoop Beginner's Guide
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Time for action – correlating of sighting duration to UFO shape


Let's do a little more detailed analysis in regards to this shape data. We wondered if there was any correlation between the duration of a sighting to the reported shape. Perhaps cigar-shaped UFOs hang around longer than the rest or formations always appear for the exact amount of time.

  1. Save the following to shapetimemapper.rb:

    #!/usr/bin/env ruby
    
    pattern = Regexp.new /\d* ?((min)|(sec))/
    
    while line = gets
    parts = line.split("\t")
    if parts.size == 6
    shape = parts[3].strip
    duration = parts[4].strip.downcase
    if !shape.empty? && !duration.empty?
    match = pattern.match(duration)
    time = /\d*/.match(match[0])[0]
    unit = match[1]
    time = Integer(time)
    time = time * 60 if unit == "min"
    puts shape+"\t"+time.to_s
    end
    end
    end
  2. Make the file executable by executing the following command:

    $ chmod +x shapetimemapper.rb
    
  3. Save the following to shapetimereducer.rb:

    #!/usr/bin/env ruby
    
    current = nil
    min = 0
    max = 0
    mean = 0
    total = 0
    count...