Book Image

Scala and Spark for Big Data Analytics

By : Md. Rezaul Karim, Sridhar Alla
Book Image

Scala and Spark for Big Data Analytics

By: Md. Rezaul Karim, Sridhar Alla

Overview of this book

Scala has been observing wide adoption over the past few years, especially in the field of data science and analytics. Spark, built on Scala, has gained a lot of recognition and is being used widely in productions. Thus, if you want to leverage the power of Scala and Spark to make sense of big data, this book is for you. The first part introduces you to Scala, helping you understand the object-oriented and functional programming concepts needed for Spark application development. It then moves on to Spark to cover the basic abstractions using RDD and DataFrame. This will help you develop scalable and fault-tolerant streaming applications by analyzing structured and unstructured data using SparkSQL, GraphX, and Spark structured streaming. Finally, the book moves on to some advanced topics, such as monitoring, configuration, debugging, testing, and deployment. You will also learn how to develop Spark applications using SparkR and PySpark APIs, interactive data analytics using Zeppelin, and in-memory data processing with Alluxio. By the end of this book, you will have a thorough understanding of Spark, and you will be able to perform full-stack data analytics with a feel that no amount of data is too big.
Table of Contents (19 chapters)

Using Scala implicits

We have addressed implicits in the previous chapters, but here we are going to see more examples. Implicit parameters are very similar to default parameters but they use different mechanisms in order to find the default value.

An implicit parameter is one that is passed to a constructor or a method and is marked as implicit, which means that the compiler will search for an implicit value within the scope if you don't provide a value for this parameter. For example:

scala> def func(implicit x:Int) = print(x) 
func: (implicit x: Int)Unit
scala> func
<console>:9: error: could not find implicit value for parameter x: Int
func
^
scala> implicit val defVal = 2
defVal: Int = 2
scala> func(3)
3

Implicits are very useful for the collection API. For example, the collections API use implicit parameters to supply CanBuildFrom...