Control Plane HA
Control Plane HA is a complete high availability Kubernetes cluster. This deployment requires three Control Plane nodes and two or more Worker nodes.
Suitable when
Three sites are available for the cluster deployment. In addition to a primary and a secondary site, a third site for Control Plane is required to complete the quorum.
Site level redundancy is needed.
Recommendations
Provide a cloud-native storage such as NFS, VSAN, or any CNCF certified cloud-native storage accessible at both sites. Though, CX may be deployed on a Kubernetes cluster where the underlying storage is not a cloud-native storage.
Limitations
Out of three control plane nodes, at least two nodes must always be up and connected for the cluster to function.
Deployment Prerequisites
At least three nodes (typically virtual machines) - one for Control Plane and two or more for worker nodes.
Full network connectivity between all nodes
Node Required | vCPU | vRAM | vDisk (GiB) | Comments | |
|---|---|---|---|---|---|
RKE2 | 3 Control Plane nodes | 2 | 4 | 50 | See RKE2 installation requirements for hardware sizing, the underlying operating system, and the networking requirements. |
CX-Core | 2 Worker nodes | 2 | 4 | 250 | If Cloud Native Storage is not available, then 2 worker nodes are required on both site-A and site-B. However, if CloudNative Storage is accessible from both sites, 1 worker node can sustain workload on each site. |
Superset | 1 Worker node | 2 | 8 | 250 | For reporting |
Network topology
For load balancing of control planes, consider any of the following three options.
External Load Balancer (ELB) | A Load balancer is used for routing the traffic to the Kubernetes cluster. For a layer-7 load balancer, you may use:
For setting up an HA cluster using external load balancer, see High Availability using External Load Balancer |
|---|---|
KubeVIP | Kube-vip provides Kubernetes clusters with a virtual IP and load balancer for both the control plane (for building a highly-available cluster) and Kubernetes Services of type LoadBalancer without relying on any external hardware or software.High Availability with Kube-VIP |
DNS | DNS can be configured to point all the traffic of a domain to any of the needed Control-Plane Nodes High Availability with DNS |