Metrics Server

The Metrics Server is a component of Kubernetes that provides container resource metrics for built-in autoscaling pipelines. It collects resource metrics from Kubelets and exposes them through the Metrics API in the Kubernetes API server. These metrics can be used by the Horizontal Pod Autoscaler and Vertical Pod Autoscaler for autoscaling purposes

It runs as a bunch of pods distributed in a cluster and fetches data from all kubelets.