OpenStack has been designed for highly scalable environments where it is possible to avoid single point of failures (SPOFs), but sometimes you must build this into your own environment. For example, Keystone is a central service underpinning your entire OpenStack environment, so you would build multiple instances into your environment. Glance is another service that is key to the running of your OpenStack environment. By setting up multiple instances running these services, controlled with Pacemaker and Corosync, we can enjoy an increase in resilience to failure of the nodes running these services. Using Pacemaker and Corosync is one way of providing a highly available solution to OpenStack services. This recipe is designed to give you options for your deployments and allow you to use Pacemaker and Corosync elsewhere in your environment.