Gaurav Gupta

Also, [this](https://github.com/gardener/machine-controller-manager/blob/rel-0.21.0/pkg/controller/deployment_rollback.go#L157), [this](https://github.com/gardener/machine-controller-manager/blob/rel-0.21.0/pkg/controller/machineset.go#L484) and [this](https://github.com/gardener/machine-controller-manager/blob/rel-0.21.0/pkg/controller/deployment_rolling.go#L279) comments are not valid for MCM. These comments seem to be taken directly from [replicaset controller](https://github.com/kubernetes/kubernetes/blob/release-1.16/pkg/controller/replicaset/replica_set.go#L592-L598)

#476 is about the failed machine metric counter, whereas this issue is about reseting the `status` field. These appear to be different issues, and hence are not duplicate. Reopening this.

@rfranzke currently the `.status.failedMachines` field in the machine deployment is reset only when all the machines controlled by the machine deployment are healthy (running and have joined the cluster). Until...

TL;DR: Generally, the approach looks good. Just thinking out loud: in absence of the upstream fix, i think introducing a configurable delay should be helpful in controlling the eviction. It...