Terminology
| Term | Meaning |
|---|---|
| Kubernetes control plane | The Kubernetes control plane is the collection of pods that manage containerized workloads on the worker nodes in a cluster. |
| Kubernetes control plane node | This is the virtual or physical machine that hosts the Kubernetes control plane, formerly known as a master node. |
| Kubernetes node or worker node | Also called a worker node, a Kubernetes node is a virtual or physical
machine that hosts containerized workloads in a cluster. To reduce ambiguity, we refer to this as a worker node in this document. |
| Contrail compute node | This is equivalent to a worker node. It is the node where the Contrail vRouter is providing the data plane function. |
| Network control plane | The network control plane provides the core SDN capability. It uses
BGP to interact with peers such as other controllers and gateway
routers, and XMPP to interact with the data plane components.
Contrail supports a centralized network control plane architecture where the routing daemon runs centrally within the Kubernetes control plane and learns and distributes routes from and to the data plane components. This centralized architecture facilitates virtual network abstraction, orchestration, and automation. |
| Network configuration plane | The network configuration plane interacts with Kubernetes control plane components to manage all Contrail resources. You configure Contrail resources using custom resource definitions (CRDs). |
| Network data plane | The network data plane resides on all nodes and interacts with containerized workloads to send and receive network traffic. Its main component is the Contrail vRouter. |
| Contrail controller | This is the part of Contrail that provides the network configuration
and network control plane functionality. The Contrail controller resides
on the Kubernetes control plane node. This name is purely conceptual – there is no corresponding Contrail controller object or entity in the UI. |
| Central cluster | In a multi-cluster deployment, this is the central Kubernetes cluster that houses the Contrail controller. |
| Workload cluster | In a multi-cluster deployment, this is the distributed cluster that contains the workloads. |