Installing the web and database servers

As of the time of writing this book, the Apache HTTP server (or just Apache for short) remains the world's most widely used web server and is often used within what is called a LAMP stack. In this stack, a Linux distribution is used as the operating system, Apache as the web server, MySQL/MariaDB as the database server, and PHP as the server-side programming language for applications. Each one of these components is free, and these technologies are widely spread and thus easy to learn/get help on.

To install the Apache and MariaDB (a free and open source fork of MySQL) servers, run the following commands on each node. Note that this will install PHP as well:

yum update && yum install httpd mariadb mariadb-server php

Upon successful installation, we will proceed as we did earlier. To begin, let's enable and start the web server on both nodes:

systemctl enable httpd
systemctl start httpd

Don't forget to make sure that Apache is running:

systemctl...