Neo4j High Performance (2015)

Preface

Welcome to the connected world. In the information age, everything around us is based on entities, relations, and above all, connectivity. Data is becoming exponentially more complex, which is affecting the performance of existing data stores. The most natural form in which data is visualized is in the form of graphs. In recent years, there has been an explosion of technologies to manage, process, and analyze graphs. While companies such as Facebook and LinkedIn have been the most well-known users of graph technologies for social web properties, a quiet revolution has been spreading across other industries. More than 30 of the Forbes Global 2000 companies, and many times as many start-ups have quietly been working to apply graphs to a wide array of business-critical use cases.

Neo4j, a graph database by Neo Technologies, is the leading player in the market for handling related data. It is not only efficient and easier to use, but it also includes all security and reliability features of tabulated databases.

We are entering an era of connected data where companies that can master the connections between their data—the lines and patterns linking the dots and not just the dots—will outperform the organizations that fail to recognize connectedness. It will be a long time before relational databases ebb into oblivion. However, their role is no longer universal. Graph databases are here to stay, and for now, Neo4j is setting the standard for the rest of the market.

This book presents an insight into how Neo4j can be applied to practical industry scenarios and also includes tweaks and optimizations for developers and administrators to make their systems more efficient and high performing.

What this book covers

Chapter 1, Getting Started with Neo4j, introduces Neo4j, its functionality, and norms in general, briefly outlining the fundamentals. The chapter also gives an overview of graphs, NOSQL databases and their features and Neo4j in particular, ACID compliance, basic CRUD operations, and setup. So, if you are new to Neo4j and need a boost, this is your chapter.

Chapter 2, Querying and Indexing in Neo4j, deals with querying Neo4j using Cypher, optimizations to data model and queries for better Cypher performance. The basics of Gremlin are also touched upon. Indexing in Neo4j and its types are introduced along with how to migrate from existing SQL stores and data import/export techniques.

Chapter 3, Efficient Data Modeling with Graphs, explores the data modeling concepts and techniques associated with graph data in Neo4j, in particular, property graph model, design constraints for Neo4j, the designing of schemas, and modeling across multiple domains.

Chapter 4, Neo4j for High-volume Applications, teaches you how to develop applications with Neo4j to handle high volumes of data. We will define how to develop an efficient architecture and transactions in a scalable way. We will also take a look at built-in graph algorithms for better traversals and also introduce Spring Data Neo4j.

Chapter 5, Testing and Scaling Neo4j Applications, teaches how to test Neo4j applications using the built-in tools and the GraphAware framework for unit and performance tests. We will also discuss how a Neo4j application can scale.

Chapter 6, Neo4j Internals, takes a look under the hood of Neo4j, skimming the concepts from the core classes in the source into the internal storage structure, caching, transactions, and related operations. Finally, the chapter deals with HA functions and master election.

Chapter 7, Administering Neo4j, throws light upon some useful tools and adapters that have been built to interface Neo4j with the most popular languages and frameworks. The chapter also deals with tips and configurations for administrators to optimize the performance of the Neo4j system. The essential security aspects are also dealt with in this chapter.

Chapter 8, Use Case – Similarity-based Recommendation System, is an example-oriented chapter. It provides a demonstration on how to go about building a similarity-based recommendation system with Neo4j and highlights the utility of graph visualization.

What you need for this book

This book is written for developers who work on machines based on Linux, Mac OS X, or Windows. All prerequisites are described in the first chapter to make sure your system is Neo4j-enabled and meets a few requirements. In general, all the examples should work on any platform.

This book assumes that you have a basic understanding of graph theory and are familiar with the fundamental concepts of Neo4j. It focuses primarily on using Neo4j for production environments and provides optimization techniques to gain better performance out of your Neo4j-based application. However, beginners can use this book as well, as we have tried to provide references to basic concepts in most chapters. You will need a server with Windows, Linux, or Mac and the Neo4j Community edition or HA installed. You will also need Python and py2neo configured.

Lastly, keep in mind that this book is not intended to replace online resources, but rather aims at complementing them. So, obviously you will need Internet access to complete your reading experience at some points, through provided links.

Who this book is for

This book was written for developers who wish to go further in mastering the Neo4j graph database. Some sections of the book, such as the section on administering and scaling, are targeted at database admins.

It complements the usual "Introducing Neo4j" reference books and online resources and goes deeper into the internal structure and large-scale deployments.

It also explains how to write and optimize your Cypher queries. The book concentrates on providing examples with Java and Cypher. So, if you are not using graph databases or using an adapter in a different language, you will probably learn a lot through this book as it will help you to understand the working of Neo4j.

This book presents an example-oriented approach to learning the technology, where the reader can learn through the code examples and make themselves ready for practical scenarios both in development and production. The book is basically the "how-to" for those wanting a quick and in-depth learning experience of the Neo4j graph database.

While these topics are quickly evolving, this book will not become obsolete that easily because it rather focuses on whys instead of hows. So, even if a given tool presented is not used anymore, you will understand why it was useful and you will be able to pick the right tool with a critical point of view.

Conventions

In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.

Code words in text are shown as follows: "This is equivalent to the assertSubGraph() method of the GraphUnit API."

A block of code is set as follows:

<artifactId>Neo4j-kernel</artifactId>

</dependency>

Any command-line input or output is written as follows:

# sudo service neo4j-service status

New terms and important words are shown in bold. Words that you see on the screen, in menus or dialog boxes for example, appear in the text like this: "Click on Finish to complete the package addition process."

Note

Warnings or important notes appear in a box like this.

Tip

Tips and tricks appear like this.