I have kubernetes 1.15.3 setup

My kube-controller & kube-scheduler are restarting very frequently . This is happening after kubernetes is upgraded to 1.15.3.

kubectl get po -n kube-system
NAME                                   READY   STATUS    RESTARTS   AGE
coredns-5c98db65d4-nmt5d               1/1     Running   37         24d
coredns-5c98db65d4-tg4kx               1/1     Running   37         24d
etcd-ana01                      1/1     Running   1          24d
kube-apiserver-ana01            1/1     Running   10         24d
**kube-controller-manager-ana01   1/1     Running   477        9d**
kube-flannel-ds-amd64-2srzb            1/1     Running   0          12d
kube-proxy-2hvcl                       1/1     Running   0          23d
**kube-scheduler-ana01            1/1     Running   518        9d**
tiller-deploy-8557598fbc-kxntc         1/1     Running   0          11d

Here is the logs of the system

  Type     Reason     Age                   From                   Message
  ----     ------     ----                  ----                   -------
  Warning  Unhealthy  39m (x500 over 23d)   kubelet, ana01  Liveness probe failed: Get http://127.0.0.1:10251/healthz: dial tcp 127.0.0.1:10251: connect: connection refused
  Warning  BackOff    39m (x1873 over 23d)  kubelet,  ana01  Back-off restarting failed container
  Normal   Pulled     28m (x519 over 24d)   kubelet, ana01  Container image "k8s.gcr.io/kube-scheduler:v1.15.3" already present on machine
  Normal   Created    28m (x519 over 24d)   kubelet, ana01  Created container kube-scheduler
  Normal   Started    27m (x519 over 24d)   kubelet, ana01  Started container kube-scheduler

logs are

I0928 09:10:23.554335       1 serving.go:319] Generated self-signed cert in-memory
W0928 09:10:25.002268       1 authentication.go:387] failed to read in-cluster kubeconfig for delegated authentication: open /var/run/secrets/kubernetes.io/serviceaccount/token: no such file or directory
W0928 09:10:25.002523       1 authentication.go:249] No authentication-kubeconfig provided in order to lookup client-ca-file in configmap/extension-apiserver-authentication in kube-system, so client certificate authentication won't work.
W0928 09:10:25.002607       1 authentication.go:252] No authentication-kubeconfig provided in order to lookup requestheader-client-ca-file in configmap/extension-apiserver-authentication in kube-system, so request-header client certificate authentication won't work.
W0928 09:10:25.002947       1 authorization.go:177] **failed to read in-cluster kubeconfig for delegated authorization: open /var/run/secrets/kubernetes.io/serviceaccount/token: no such file or directory**
W0928 09:10:25.003116       1 authorization.go:146] No authorization-kubeconfig provided, so SubjectAccessReview of authorization tokens won't work.
I0928 09:10:25.021201       1 server.go:142] Version: v1.15.3