OpenStack On Containers

We've talked about containers on OpenStack, but as OpenStack evolves, more motion is being directed to running OpenStack on containers. Today, the most common architecture for OpenStack clouds consists of one or more bare metal servers that house the control services in order to operate OpenStack. When configured for high availability, these bare metal servers can scale horizontally, but for the most part, they will contain the exact same control plane services on each server. We call this a monolithic control plane design. The limitations of this design are mostly centered around scaling the services, both stateful and stateless. Although most of OpenStack's stateless servers can scale horizontally very wide, there are some issues with the stateful services and the way they are load balanced. This presents limitations to horizontal scaling; for example, when scaling corosync, you are limited to 16 cluster members, in some cases more, but none have been well tested...