Book Image

Learning Apache Spark 2

Book Image

Learning Apache Spark 2

Overview of this book

Apache Spark has seen an unprecedented growth in terms of its adoption over the last few years, mainly because of its speed, diversity and real-time data processing capabilities. It has quickly become the preferred choice of tool for many Big Data professionals looking to find quick insights from large chunks of data. This book introduces you to the Apache Spark framework, and familiarizes you with all the latest features and capabilities introduced in Spark 2. Starting with a detailed introduction to Spark’s architecture and the installation procedure, this book covers everything you need to know about the Spark framework in the most practical manner. You will learn how to perform the basic ETL activities using Spark, and work with different components of Spark such as Spark SQL, as well as the Dataset and DataFrame APIs for manipulating your data. Then, you will perform machine learning using Spark MLlib, as well as perform streaming analytics and graph processing using the Spark Streaming and GraphX modules respectively. The book also gives special emphasis on deploying your Spark models, and how they can be operated in a clustered mode. During the course of the book, you will come across implementations of different real-world use-cases and examples, giving you the hands-on knowledge you need to use Apache Spark in the best possible manner.
Table of Contents (18 chapters)
Learning Apache Spark 2
Credits
About the Author
About the Reviewers
www.packtpub.com
Customer Feedback
Preface

Actions


As discussed previously, Actions are what makes Spark perform the actual computation from the graph that the framework has been building in the background while you were busy performing transformations on it. While there is a long list of actions offered by Spark, we'll list the most common actions offered by Spark and take you through some of the most common ones:

reduce(func)

takeOrdered(n, [ordering])

collect()

saveAsTextFile(path)

count()

saveAsSequenceFile(path)*

first()

saveAsObjectFile(path) *

take(n)

foreach(func)

takeSample(withReplacement,num, [seed])

Tip

The methods saveAsSequenceFile() and saveAsObjectFil() are only available in Java and Scala.

We have already seen reduce(), collect(), and count() in the previous examples, so we'll be quickly going through their semantics, but will not provide examples for the sake of brevity.

Reduce(func)

As the name implies, reduce performs aggregation on the input dataset, which is often the result of a...