Summary

In this chapter, you have learned some of the most important concepts about high availability and failover. You have also learned the different options available to build a redundant OpenStack architecture within a robust resiliency. You now know how to diagnose your OpenStack design by eliminating any SPOF across all services. We have highlighted different open source solutions out of the box to arm our OpenStack infrastructure and make it as fault tolerant as possible. Different technologies have been introduced, such as HAProxy database replication using Galera, Keepalived, Pacemaker, and Corosync. New advanced built-in HA mechanisms for networks were introduced within the latest releases of OpenStack (Juno and later). HA routers using VRRP and DVR are very promising solutions that tackle the issue of network failure in an OpenStack environment. This presents a great step forward to architect a high available...