OpenStack Cluster – The Cloud Controller and Common Services

"If you want to go quickly, go alone. If you want to go far, go together."
                                                                                      - African proverb

Now that you have good knowledge of the approaches taken to deploy a large OpenStack infrastructure in an automated way, it is time to pe deeper and cover more specific conceptual designs within OpenStack.

In a large infrastructure, especially if you are looking to keep all your services up
and running, it is essential that you ensure the OpenStack infrastructure is reliable and guarantees business continuity.

We already discussed several design aspects and highlighted some best practices of scalable architecture models within OpenStack in Chapter 1, Designing OpenStack Cloud Architectural Consideration.

Soon after, we discovered the efficiency of automation, where we resumed a basic setup of an all-in-one cloud controller and compute node using the OpenStack Ansible deployment tool.

This chapter begins by covering some clustering aspects. It soon guides you
to discover more OpenStack design patterns based on breaking down functionality into different services while focusing on the cloud controller. Bear in mind that this chapter will not treat high availability in detail and will not touch on all OpenStack service layers. Instead, it will aim to give a generic overview of several possibilities of the OpenStack clustering design. The art of clustering is the key to providing a solution that fits into a methodology that stresses standardized, consistent IT build-out OpenStack operations.

In this chapter, we will cover the following topics:

• Covering, briefly, the art of clustering
• Defining the use case of cloud controllers and common services in an
  OpenStack environment
• Introducing other OpenStack clustering models based on the distribution of functionality based on services on the cloud controller
• Understanding common infrastructure services
• Learning the OpenStack services that compose the controller nodes
• Getting to grips with the automation of infrastructure deployment using Ansible in OpenStack