In kubernetes two concepts I found very interesting: ⁠Only the API Server writes to etcd Controllers don’t directly modify etcd. If HPA decides that the application needs 5 replicas instead of 3, it doesn’t go directly to etcd and change the value. It talks to the API Server. The API Server handles the request, applies authentication, authorization and admission controls, and then persists the desired state in etcd. This gives Kubernetes a single controlled entry point for modifying cluster state. It also means the other components don’t need to understand how etcd works or deal with…

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