Error from server (ServiceUnavailable): the server is currently unable to handle the request

[alanh0vx]

executing the command kubectl top nodes, seems it's freezed

executing the command kubectl get --raw /apis/metrics.k8s.io/v1beta1
it returned Error from server (ServiceUnavailable): the server is currently unable to handle the request

view the logs from metrics-server

http: TLS handshake error from 192.168.133.64:51926:EOF

192.168.133.64 is the internal ip address of api-server

from api-server log

E1214 02:06:35.625504       1 memcache.go:134] couldn't get resource list for metrics.k8s.io/v1beta1: the server is currently unable to handle the request
E1214 02:07:05.573958       1 available_controller.go:311] v1beta1.metrics.k8s.io failed with: Get https://10.109.179.236:443: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
E1214 02:07:05.658841       1 memcache.go:134] couldn't get resource list for metrics.k8s.io/v1beta1: the server is currently unable to handle the request

kubelet version is 1.12.3
metrics-server 0.3.1

i have another clusters-set with the same version and configuration, metrics-server works just fine

api-server parameters

 - command:
    - kube-apiserver
    - --authorization-mode=Node,RBAC
    - --advertise-address=10.100.1.2
    - --allow-privileged=true
    - --client-ca-file=/etc/kubernetes/pki/ca.crt
    - --enable-admission-plugins=NodeRestriction
    - --enable-bootstrap-token-auth=true
    - --etcd-cafile=/etc/kubernetes/pki/etcd/ca.crt
    - --etcd-certfile=/etc/kubernetes/pki/apiserver-etcd-client.crt
    - --etcd-keyfile=/etc/kubernetes/pki/apiserver-etcd-client.key
    - --etcd-servers=https://127.0.0.1:2379
    - --insecure-port=0
    - --kubelet-client-certificate=/etc/kubernetes/pki/apiserver-kubelet-client.crt
    - --kubelet-client-key=/etc/kubernetes/pki/apiserver-kubelet-client.key
    - --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname
    - --proxy-client-cert-file=/etc/kubernetes/pki/front-proxy-client.crt
    - --proxy-client-key-file=/etc/kubernetes/pki/front-proxy-client.key
    - --requestheader-allowed-names=front-proxy-client
    - --requestheader-client-ca-file=/etc/kubernetes/pki/front-proxy-ca.crt
    - --requestheader-extra-headers-prefix=X-Remote-Extra-
    - --requestheader-group-headers=X-Remote-Group
    - --requestheader-username-headers=X-Remote-User
    - --secure-port=6443
    - --service-account-key-file=/etc/kubernetes/pki/sa.pub

[garenwen]

Have you solved the problem？

[serathius]

Have you seen log that metrics-server successfully generated certificate?
I had cases when it could take 2-3 minutes for metrics server to be able to serve tls.

[alanh0vx]

no, it still gives the same errors

any other places that i can check

[serathius]

I would increase verbosity in metrics-server and try to find something in logs

[abdennour]

Has someone solved the problem？

[alanh0vx]

just keep having such logs

I1220 09:39:33.000928       1 logs.go:49] http: TLS handshake error from 192.168.133.64:45734: EOF
I1220 09:40:02.985989       1 logs.go:49] http: TLS handshake error from 192.168.133.64:45794: EOF
I1220 09:40:10.416586       1 manager.go:95] Scraping metrics from 5 sources
I1220 09:40:10.419951       1 manager.go:120] Querying source: kubelet_summary:k83.xxxx.xxx
I1220 09:40:10.424855       1 manager.go:120] Querying source: kubelet_summary:k82.xxxx.xxx
I1220 09:40:10.427763       1 manager.go:120] Querying source: kubelet_summary:k84.xxxx.xxx
I1220 09:40:10.435885       1 manager.go:120] Querying source: kubelet_summary:k85.xxxx.xxx
I1220 09:40:10.446844       1 manager.go:120] Querying source: kubelet_summary:k81.xxxx.xxx
I1220 09:40:16.078000       1 manager.go:150] ScrapeMetrics: time: 5.661316126s, nodes: 5, pods: 46

[d0o0bz]

try to edit the metrics-server-deployment.yaml file and add command parameters :

  containers:
    command:
    - /metrics-server
    - --kubelet-insecure-tls
    - --kubelet-preferred-address-types=InternalIP
    volumeMounts:
    - name: tmp-dir
      mountPath: /tmp

[alanh0vx]

thanks, turned out it's MTU issue

from calico config, it was 1500 while the interface is 1450

finally kubectl edit configmap calico-config -n kube-system and change the MTU value from 1500 to 1430

[Darren-wh]

you can add this
command:
- /metrics-server
- --metric-resolution=30s
- --requestheader-allowed-names=aggregator
- --kubelet-insecure-tls
- --kubelet-preferred-address-types=InternalIP,Hostname,InternalDNS,ExternalDNS,ExternalIP
it will work

[kevinsingapore]

to reinstall the metrics-server again；
follow the way，i had sovle the error.

[NEWgaofeng]

InternalIP need view localhost ip ?

[NEWgaofeng]

my yaml

apiVersion: v1
kind: Pod
metadata:
  name: cpu-demo
  namespace: cpu-example
spec:
  containers:
  - name: cpu-demo-ctr
    image: vish/stress
    resources:
      limits:
        cpu: "1"
      requests:
        cpu: "0.5"
    args:
    - -cpus
    - "2"

i input node command:
kubectl apply -f cpu-request-limit.yaml
then
kubectl top pod cpu-demo --namespace=cpu-example

but Errors：
Error from server (ServiceUnavailable): the server is currently unable to handle the request (get nodes.metrics.k8s.io)