<p>Now I found my kubernetes v1.21 cluster no response with any command, for example, when I scale the deployment pod number, nothing change with the deployment. also there is no error info output. is it possible to debug the command, how to found out where is the issue? I have checked the kubelet:</p>
<pre><code>[root@k8smasterone ~]# systemctl status kubelet
● kubelet.service - kubelet: The Kubernetes Node Agent
   Loaded: loaded (/usr/lib/systemd/system/kubelet.service; enabled; vendor preset: disabled)
   Active: active (running) since Fri 2023-08-04 16:31:37 CST; 1h 28min ago
     Docs: https://kubernetes.io/docs/
 Main PID: 6067 (kubelet)
    Tasks: 15
   Memory: 73.4M
   CGroup: /system.slice/kubelet.service
           └─6067 /usr/bin/kubelet --bootstrap-kubeconfig=/etc/kubernetes/bootstrap-kubelet.conf --kubeconfig=/etc/kubernetes/kubelet.conf --config=/var/lib/kubelet/config.yaml --container-runtime=remote --container-runtime-endpoint=/run/co...
</code></pre>
<p>the controller manager:</p>
<pre><code>[root@k8smasterone ~]#  ps aux|grep &quot;controller&quot;
polkitd   3055  0.1  4.3 1022732 342976 ?      Ssl   2022 601:27 /usr/bin/kube-controllers
root     10433  0.0  0.5 819636 44476 ?        Ssl  02:52   0:53 kube-controller-manager --allocate-node-cidrs=true --authentication-kubeconfig=/etc/kubernetes/controller-manager.conf --authorization-kubeconfig=/etc/kubernetes/controller-manager.conf --bind-address=127.0.0.1 --client-ca-file=/etc/kubernetes/pki/ca.crt --cluster-cidr=10.96.0.0/12 --cluster-name=kubernetes --cluster-signing-cert-file=/etc/kubernetes/pki/ca.crt --cluster-signing-key-file=/etc/kubernetes/pki/ca.key --controllers=*,bootstrapsigner,tokencleaner --kubeconfig=/etc/kubernetes/controller-manager.conf --leader-elect=true --requestheader-client-ca-file=/etc/kubernetes/pki/front-proxy-ca.crt --root-ca-file=/etc/kubernetes/pki/ca.crt --service-account-private-key-file=/etc/kubernetes/pki/sa.key --service-cluster-ip-range=10.96.0.0/12 --use-service-account-credentials=true
</code></pre>
<p>the scheduler manager:</p>
<pre><code>[root@k8smasterone ~]# ps aux|grep &quot;scheduler&quot;
root     10667  0.2  0.3 752032 30780 ?        Ssl  02:52   2:11 kube-scheduler --authentication-kubeconfig=/etc/kubernetes/scheduler.conf --authorization-kubeconfig=/etc/kubernetes/scheduler.conf --bind-address=127.0.0.1 --kubeconfig=/etc/kubernetes/scheduler.conf --leader-elect=true
</code></pre>
<p>all of them works fine. what should I do to fixed this issue? the recently change of my cluster is renewed the certificate.</p>

Dolphin
<p>As you mentioned, the k8s cluster certificates are renewed.  Please ensure you update the latest certificates in home directory by running below command as an normal user.  More details of manual certificate renewal can be referred in following <a href="https://kubernetes.io/docs/tasks/administer-cluster/kubeadm/kubeadm-certs/#manual-certificate-renewal" rel="nofollow noreferrer">k8s documentation</a></p>
<pre><code>sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
</code></pre>
<p>Also the tools like kubectl, kubeadm can be debugged by passing &quot;--v=9&quot; flag.  More details of the verbosity for kubectl is there in <a href="https://kubernetes.io/docs/reference/kubectl/cheatsheet/#kubectl-output-verbosity-and-debugging" rel="nofollow noreferrer">k8s documentation</a></p>
