There are a number of node types used in OpenStack. Nodes are a physical host computer, with an operating system installed, with Oracle Linux using KVM (Kernel-based Virtual Machine) . The main node types we discuss in this guide are:
A controller node is a system running Oracle Linux, and is where most of the OpenStack services are installed. The term controller node is used to discuss nodes that do not run virtual machine instances. The controller nodes may have all the non-compute services or only some of them. A controller node may also include the Oracle OpenStack for Oracle Linux toolkit, which is used to perform the deployment of OpenStack services to other nodes.
A compute node is a system running Oracle Linux using KVM . A compute node runs the bare minimum of services to manage virtual machine instances.
A database node is a system running Oracle Linux, and the services required to manage databases for images and instances.
A network node is a system running Oracle Linux, and runs the neutron network worker daemon. The neutron worker daemon provides services such as providing an IP address to a booting Nova instance.
A storage node is a system running Oracle Linux and the services required to manage storage for images and instances.
A master node is a system running Oracle Linux, and the Oracle OpenStack for Oracle Linux toolkit used to deploy the OpenStack services to the nodes. A master node is not an OpenStack node, but the Oracle OpenStack for Oracle Linux toolkit may be installed on a controller node.
More detailed information on the node types is available in the OpenStack Operations Guide at:
http://docs.openstack.org/openstack-ops/content/example_architecture.html#node_types