An overview of HA topologies
In this section, we’ll look at the two most common HA topologies for enabling HA clusters. The Kubernetes cluster’s control plane is mostly stateless. The cluster datastore, which operates as the one source of truth for the whole cluster, is the only stateful component of the control plane. Internal and external consumers can access and alter the state through the API server, which serves as a gateway to the cluster datastore. MicroK8s uses Dqlite, a distributed and highly accessible variant of SQLite, as the key-value database to preserve the cluster’s state.
Before looking at the HA topologies, let us look at potential failure scenarios that could hamper cluster operations:
- Loss of control plane (master) node: Loss of the master node or its services will have a major impact. The cluster will be unable to respond to API commands or the deployment of nodes. Each service in the master node, as well as the storage layer, is...
