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

Doing classification using gradient boosted trees


Another ensemble learning algorithm is gradient boosted trees (GBTs). GBTs train one tree at a time, where each new tree improves upon the shortcomings of the previously trained trees.

As GBTs train one tree at a time, they can take longer than random forest.

Getting ready

Let us do GBT on the same patient data and see how the accuracy differs. 

How to do it...

  1. Start the Spark shell:
$ spark-shell
  1. Perform the required imports:
scala> import org.apache.spark.ml.classification.{GBTClassificationModel,
        GBTClassifier}
scala> import 
        org.apache.spark.ml.evaluation.MulticlassClassificationEvaluator
  1. Load and parse the data:
        scala> val data = 
        spark.read.format("libsvm").load("s3a://sparkcookbook/patientdata")
  1. Split the data into training and test datasets:
scala> val Array(training, test) = data.randomSplit(Array(0.7, 0.3))
  1. Create a classification as a boosting strategy and set the number of iterations to 3:
scala&gt...