Book Image

Apache Spark 2.x for Java Developers

By : Sourav Gulati, Sumit Kumar
Book Image

Apache Spark 2.x for Java Developers

By: Sourav Gulati, Sumit Kumar

Overview of this book

Apache Spark is the buzzword in the big data industry right now, especially with the increasing need for real-time streaming and data processing. While Spark is built on Scala, the Spark Java API exposes all the Spark features available in the Scala version for Java developers. This book will show you how you can implement various functionalities of the Apache Spark framework in Java, without stepping out of your comfort zone. The book starts with an introduction to the Apache Spark 2.x ecosystem, followed by explaining how to install and configure Spark, and refreshes the Java concepts that will be useful to you when consuming Apache Spark's APIs. You will explore RDD and its associated common Action and Transformation Java APIs, set up a production-like clustered environment, and work with Spark SQL. Moving on, you will perform near-real-time processing with Spark streaming, Machine Learning analytics with Spark MLlib, and graph processing with GraphX, all using various Java packages. By the end of the book, you will have a solid foundation in implementing components in the Spark framework in Java to build fast, real-time applications.
Table of Contents (19 chapters)
Title Page
About the Authors
About the Reviewer
Customer Feedback

Dataframe and dataset

Dataframes were introduced in Spark 1.3. Dataframe built on the concept of providing schemas over the data. An RDD basically consists of raw data. Although it provides various functions to process the data, it is a collection of Java objects and is involved in the overhead of garbage collection and serialization. Also, Spark SQL concepts can only be leveraged if it contains some schema. So, earlier version of a Spark provide another version of RDD called SchemaRDD.


As its name suggests, it is an RDD with schema. As it contains schema, run relation queries can be run on the data along with basic RDD functions. The SchemaRDD can be registered as a table so that SQL queries can be executed on it using Spark SQL. It was available in earlier version of a Spark. However, with Spark Version 1.3, the SchemaRDD was deprecated and dataframe was introduced.


In spite of being an evolved version of SchemaRDD, dataframe comes with big differences to RDDs. It was introduced...