How do I configure a 2 node high availability cluster on RHEL/Centos 7.6?
You will need pacemaker, corosync and pcs packages for making two node cluster in RHEL/CentOS 7 servers.
These packages or cluster components define as below:
Pacemaker is an open source cluster manager software which provide high availability of resources or services in CentOS 7 or RHEL 7 Linux. It has feature of scalable and advanced HA Cluster Manager. This HA cluster manager distributed by ClusterLabs.
Corosync is the core of Pacemaker Cluster Manager as it is responsible for generating heartbeat communication between cluster nodes which make it capable of deploying High Availability in applications. Corosync is derived from an Open Source project OpenAIS under new BSD License.
Pcsd is a Pacemaker command line interface (CLI) and GUI for managing the Pacemaker cluster. PCSD command pcs is use for creating, configuring and adding a new node to cluster.
You will like to read my tutorial which I have written in my blog on these mentioned pacemaker cluster components installation and configuration for building two nodes webserver basic cluster:
Simple way to configure Ngnix High Availability Web Server with Pacemaker and Corosync on CentOS7