Readiness as no reasoning to be cluster scope
because that is not how the k8s networking works
for pods, all the pods to a deployment are not
sharing the network in a singleton. Instead they
are run as local scopes to themselves, with
readiness failures the pod is potentially taken
out of the network to be resolvable - this
affects the distributed setup in myriad of
different ways.
Instead readiness should behave like liveness
with local scope alone, and should be a dummy
implementation.
This PR all the startup times and overal k8s
startup time dramatically improves.
Added another handler called as `/minio/health/cluster`
to understand the cluster scope health.
This PR adds a new configuration parameter which allows readiness
check to respond within 10secs, this can be reduced to a lower value
if necessary using
```
mc admin config set api ready_deadline=5s
```
or
```
export MINIO_API_READY_DEADLINE=5s
```
Add two new configuration entries, api.requests-max and
api.requests-deadline which have the same role of
MINIO_API_REQUESTS_MAX and MINIO_API_REQUESTS_DEADLINE.
