Chapter 4. Real-world Implementations of Clustering

In this chapter, you will learn how to use your cluster in real-life scenarios by deploying a web server and a database server. Before we do this, we will need to review some fundamental concepts related to these key components, configure replicated storage so that files are kept in sync between nodes, and then finally, populate our database with sample data, which we will then query using a simple PHP application.

Since the programming side of things is out of the scope of this book, feel free to use some other programming language of your choice if you want to do so. I have chosen PHP for simplicity. Keep in mind that this book is not aimed at teaching you how to build web-based applications for use in a CentOS 7 cluster, but rather how to use it in order to provide high availability for those applications.

During the course of this chapter, you will notice that we will rely on the concepts introduced and the services configured...