In this chapter, we will look at the components of a high-availability cluster in greater detail than we were able to do initially during Chapter 1, Cluster Basics and Installation on CentOS 7; you may want to review that chapter in order to refresh your memory before proceeding further.
In this chapter, we will cover the following topics:
Failover—a premier on high availability and performance
Fencing — isolating the malfunctioning nodes
Split brain — preparing to avoid inconsistencies
Quorum — scoring inside your cluster
Configuring our cluster via PCS GUI
We will set out on this chapter by asking ourselves a few questions about how to achieve high availability, and we will attempt to get our answers as we go along. In the next chapter, we will set up actual real-life examples:
How can we ensure an automatic failover without the need for human intervention?
How many nodes are needed in a cluster in order to ensure high availability in several failure...