How to resolve scheduler unhealthy state in Kubernetes , Error: http://127.0.0.1:10251/healthz": dial tcp 127.0.0.1:10251: connect: connection refused

How to resolve scheduler  unhealthy state in Kubernetes

 Symptom:

When we install the new kubernetes cluster. When we execute the following command:

$ kubectl get cs / kubectl get componentstatuses

we get this error:

root@k8s-master:~# kubectl get cs
Warning: v1 ComponentStatus is deprecated in v1.19+
NAME                 STATUS      MESSAGE                                                                                       ERROR
scheduler            Unhealthy   Get "http://127.0.0.1:10251/healthz": dial tcp 127.0.0.1:10251: connect: connection refused
etcd-0               Healthy     {"health":"true","reason":""}
controller-manager   Healthy     ok
root@k8s-master:~#

Solution:
Modify the following files on all master nodes:
$ sudo vi /etc/kubernetes/manifests/kube-scheduler.yaml
Clear the line (spec->containers->command) containing this phrase: - --port=0

$ sudo systemctl restart kubelet.service

root@k8s-master:~# vi /etc/kubernetes/manifests/kube-scheduler.yaml
root@k8s-master:~# systemctl restart kubelet.service
root@k8s-master:~# kubectl get cs
Warning: v1 ComponentStatus is deprecated in v1.19+
NAME                 STATUS    MESSAGE                         ERROR
controller-manager   Healthy   ok
etcd-0               Healthy   {"health":"true","reason":""}
scheduler            Healthy   ok
root@k8s-master:~#