Note
Access to this page requires authorization. You can try signing in or changing directories.
Access to this page requires authorization. You can try changing directories.
Azure Red Hat OpenShift is available in two architecture models: the standard architecture and the hosted control planes (HCP) architecture. Both models provide a fully managed OpenShift experience jointly engineered by Red Hat and Microsoft, but they differ in how the control plane is deployed, how clusters are scaled and upgraded, and what infrastructure you manage.
This article summarizes the key differences between the two models to help you decide which one best fits your requirements.
Architecture overview
The most significant difference between the two architectures is where the control plane runs.
In the standard architecture, the control plane runs on dedicated virtual machines in your Azure subscription. You deploy both the control plane nodes and worker nodes in your virtual network, and you can see them in your Azure account.
In the hosted control planes (HCP) architecture, Red Hat hosts the control plane in a Red Hat-owned Azure account. You deploy only the worker nodes in your Azure subscription and virtual network. Red Hat fully manages the control plane components, including the API server and etcd database, in an isolated environment.
Key differences
The following table summarizes the key differences between the two architecture models.
| Feature | Standard architecture | Hosted control planes |
|---|---|---|
| Control plane hosting | Control plane components, such as the API server and etcd database, are hosted on dedicated virtual machines in your Azure subscription. | Control plane components, such as the API server and etcd database, are hosted in a Red Hat-owned Azure account. |
| Virtual network | Worker nodes and control plane nodes are deployed in your virtual network. | Worker nodes are deployed in your virtual network. The control plane communicates with worker nodes over a dedicated VNet integration subnet delegated to Microsoft.RedHatOpenShift/hcpOpenShiftClusters. |
| Multi-zone deployment | The control plane can be deployed within a single availability zone or across multiple availability zones. | The control plane automatically spans three availability zones in the installed region. |
| Node pools | Machine sets define groups of worker nodes. Node pools can be deployed in a single availability zone or across multiple availability zones. | Each node pool is deployed into a single availability zone. You can deploy separate node pools across different availability zones for high availability. |
| Infrastructure nodes | Uses dedicated infrastructure nodes to host platform components, such as the ingress controller and image registry. | Doesn't use dedicated infrastructure nodes. Platform components such as the ingress controller, image registry, and monitoring are deployed on worker nodes. |
| OpenShift platform components | Platform monitoring, image registry, and the ingress controller are deployed on dedicated infrastructure nodes. | Platform monitoring, image registry, and the ingress controller are deployed on worker nodes. |
| Cluster upgrades | The control plane and worker nodes are upgraded together as a coordinated process. | The control plane and each node pool can be upgraded separately. Control plane z-stream (patch) upgrades are automatic and managed by Red Hat SRE. |
| Minimum compute footprint | Three control plane nodes and three worker nodes are required to create a cluster. | Two worker nodes are required to create a cluster. No control plane nodes are deployed in your subscription. |
| Cluster provisioning time | It takes approximately 45 minutes to create a cluster. | It takes approximately 15 to 20 minutes to create a cluster. |
| Billing | You pay for all nodes in your subscription, including three control plane nodes, three worker nodes, and any additional worker nodes. You pay node costs at Azure Linux virtual machine rates, plus an Azure Red Hat OpenShift license component per application node. For more information, see Azure Red Hat OpenShift pricing. | You pay for worker nodes only (minimum of two). You don't deploy control plane nodes in your subscription, and you don't need dedicated infrastructure nodes. For more information, see Azure Red Hat OpenShift pricing. |