The first and easiest way to scale an OpenStack cluster is to add compute power. One control node and one network node can support more than one compute node. Remember installing RDO in Chapter 2, RDO Installation? We have come a long way since then! In that example, only one compute node was installed. One control and one network node can support a large collection of compute nodes. The exact number that can be handled depends on the demand put on the cluster by its end users. It is probably safe to say that the capacity provided by one compute node probably isn't going to meet most use cases, so let's take a look at how to add additional compute nodes to our OpenStack installation.

Technically, there are only two OpenStack services plus the supporting networking infrastructure that need to be running for a new compute node to be joined into an OpenStack cluster and start sharing the computing workload. These two services are the Nova compute service and the Neutron...