Book Image

Apache Spark 2.x Cookbook

By : Rishi Yadav
Book Image

Apache Spark 2.x Cookbook

By: Rishi Yadav

Overview of this book

While Apache Spark 1.x gained a lot of traction and adoption in the early years, Spark 2.x delivers notable improvements in the areas of API, schema awareness, Performance, Structured Streaming, and simplifying building blocks to build better, faster, smarter, and more accessible big data applications. This book uncovers all these features in the form of structured recipes to analyze and mature large and complex sets of data. Starting with installing and configuring Apache Spark with various cluster managers, you will learn to set up development environments. Further on, you will be introduced to working with RDDs, DataFrames and Datasets to operate on schema aware data, and real-time streaming with various sources such as Twitter Stream and Apache Kafka. You will also work through recipes on machine learning, including supervised learning, unsupervised learning & recommendation engines in Spark. Last but not least, the final few chapters delve deeper into the concepts of graph processing using GraphX, securing your implementations, cluster optimization, and troubleshooting.
Table of Contents (19 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Understanding Spark ML


Spark ML is a nickname for the DataFrame-based MLLib API. Spark ML is the primary library now, and the RDD-based API has been moved to maintenance mode.  

Getting ready

Let's first understand some of the basic concepts in Spark ML. Before that, let's quickly go over how the learning process works. Following are the steps:

  1. A machine learning algorithm is provided a training dataset along with the right hyperparameters. 
  2. The result of training is a model. The following figure illustrates the model building by applying machine learning algorithm on training data with hyperparameters: 
  1. The model is then used to make predictions on test data as shown here:

In Spark ML, an estimator is provided as a DataFrame (via the fit method), and the output after training is a Transformer:

Now, the Transformer takes one DataFrame as input and outputs another transformed (via the transform method) DataFrame. For example, it can take a DataFrame with the test data and enrich this DataFrame with...