Installing Pacemaker
All OpenStack services consist of system Linux services. The first step of ensuring services' availability is to configure Pacemaker clusters for each service, so Pacemaker monitors the services. In case of failure, Pacemaker restarts the failed service. In addition, we will use Pacemaker to create a virtual IP address for each of OpenStack's services to ensure services are accessible using the same IP address when failures occurs and the actual service has relocated to another host.
In this section, we will install Pacemaker and prepare it to configure highly available OpenStack services.
Getting ready
To ensure maximum availability, we will install and configure three hosts to serve as controller nodes. Prepare three controller hosts with identical hardware and network layouts. We will base our configuration for most of the OpenStack services on the configuration used in a single controller layout, and we will deploy Neutron network services on all three controller nodes...
