In this three-part blog series, we will explain the details and functionality of a High Availability (HA) framework for MySQL hosting using MySQL semisynchronous replication and the Corosync plus Pacemaker stack. In Part I, we’ll walk you through the basics of High Availability, the components of an HA framework, and then introduce you to the HA framework for MySQL.

What is High Availability?

The availability of a computer system is the percentage of time its services are up during a period of time. It’s generally expressed as a series of 9′s. For example, the table below shows availability and the corresponding downtime measured over one year.

In this blog post, we review some of the important aspects of configuring and managing SSL in MySQL hosting. These would include the default configuration, disabling SSL, and enabling and enforcing SSL on a MySQL server. Our observations are based on the community version of MySQL 5.7.21.

Default SSL Configuration in MySQL

By default, MySQL server always installs and enables SSL configuration. However, it is not enforced that clients connect using SSL. Clients can choose to connect with or without SSL as the server allows both types of connections. Let’s see how to verify this default behavior of MySQL server.

When SSL is installed and enabled on MySQL server by default, we will typically see the following:

1. Presence of *.pem files in the MySQL data directory. These are the various client and server certificates and keys that are in …