Types of Openstack configuration

Types of OpenStack Configuration and Deployment

OpenStack can be deployed OpenStack is of course a culmination of loosely-coupled projects that define services. A node is nothing more than a grouping of OpenStack services that run on bare metal, in a container or virtual machine. The purpose of a node is to provide horizontal scaling and HA. in a single-node or multi-node configuration.

Multi-node Configurations

While single-node configurations are acceptable for small environments, testing or POCs most production environments will require a multi-node configuration for various reasons. As mentioned multi-node configurations group similar OpenStack services and provide scalability as well as the possibility for high availability. One of the great things about OpenStack is its architecture. Every service is decoupled and all communication between services is done through RESTful API endpoints. This is the model architecture for the cloud. The advantages are that we have tremendous flexibility in how to build a multi-node configuration. While a few standards have emerged there are many more possible variations and in the end, we are not stuck to a rigid deployment model. The standards for deploying multi-node OpenStack are as a two-node, three-node, or four-node configuration. 

Two-Node Openstack Configuration

The two-node configuration has a controller and computes the node. Here we can easily scale out compute nodes. Most likely we would run just one controller node or we could set up an active/passive HA configuration for the controller node using Pacemaker. Below is an illustration of a two-node OpenStack configuration: 

Three-Node Openstack Configuration

The three-node configuration has a controller, compute, and network node. Here we can easily scale out compute or network nodes. Most likely we would run just one controller node or we could set up an active/passive HA configuration for the controller node using Pacemaker. In addition, we could also set up an active/passive configuration for the network node to achieve HA and horizontal scaling depending on resource requirements. 

Four-Node Openstack Configuration

The four-node configuration has a controller, compute, network, and storage node. Here we can easily scale out compute, network, and storage nodes. Most likely we would run just one controller node or we could set up an active/passive HA configuration for the controller node using Pacemaker. In addition, we could also set up active/passive configuration for network and storage nodes to achieve HA as well as horizontal scaling depending on resource requirements.