---
title: Node metrics data
content_type: reference
weight: 50
description: >-
  Mechanisms for accessing metrics at node, volume, pod and container level,
  as seen by the kubelet.
---

The [kubelet](/docs/reference/command-line-tools-reference/kubelet/)
gathers metric statistics at the node, volume, pod and container level,
and emits this information in the
[Summary API](https://github.com/kubernetes/kubernetes/blob/7d309e0104fedb57280b261e5677d919cb2a0e2d/staging/src/k8s.io/kubelet/pkg/apis/stats/v1alpha1/types.go).

You can send a proxied request to the stats summary API via the
Kubernetes API server.

Here is an example of a Summary API request for a node named `minikube`:

```shell
kubectl get --raw "/api/v1/nodes/minikube/proxy/stats/summary"
```

Here is the same API call using `curl`:

```shell
# You need to run "kubectl proxy" first
# Change 8080 to the port that "kubectl proxy" assigns
curl http://localhost:8080/api/v1/nodes/minikube/proxy/stats/summary
```

{{< note >}}
Beginning with `metrics-server` 0.6.x, `metrics-server` queries the `/metrics/resource`
kubelet endpoint, and not `/stats/summary`.
{{< /note >}}

## Summary metrics API source {#summary-api-source}

By default, Kubernetes fetches node summary metrics data using an embedded
[cAdvisor](https://github.com/google/cadvisor) that runs within the kubelet. If you 
enable the `PodAndContainerStatsFromCRI` [feature gate](/docs/reference/command-line-tools-reference/feature-gates/) 
in your cluster, and you use a container runtime that supports statistics access via
{{< glossary_tooltip term_id="cri" text="Container Runtime Interface">}} (CRI), then
the kubelet [fetches Pod- and container-level metric data using CRI](/docs/reference/instrumentation/cri-pod-container-metrics), and not via cAdvisor.

## {{% heading "whatsnext" %}}

The task pages for [Troubleshooting Clusters](/docs/tasks/debug/debug-cluster/) discuss
how to use a metrics pipeline that rely on these data.