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 (12 chapters)

What is a graph?


A graph is a mathematical representation of linked data. It is a study of relationships or relationships objects, and it is formed by vertices (also known as nodes or points), which are connected by edges (also known as arcs or lines). A graph may be directed or undirected, where a directed graph implies that edges have direction associated with them, while an undirected graph implies that the edges do not have a direction associated with them.

A graph is therefore represented as an ordered pair of G=(V,E) where V is a set of vertices, nodes, or points connected by E, which is a set of edges, arcs, or lines. For example, in Figure 7.1, we have a set of vertices numbered 1 to 7, and certain vertices are connected by more than one edges, for example, 4 connected to vertices 1,2,3,6 while 7 is only connected to 6.

Figure 7.1: An example of a Graph

In computer science, graphs are used to represent networks of communication such as data organization, a set of computational...