Alice wants to configure her app so that each instance that becomes unreachable is replaced as soon as Marathon receives a status update TASK_UNREACHABLE.
- allow a configuration that transitions instances to inactive as soon as they are reported as Unreachable by Mesos (e.g. by allowing inactiveAfterSeconds: 0).
- With the given configuration, Marathon must transition an instance to UnreachableInactive on first sight of a respective status update for any task contained in the instance.
- Marathon must schedule a new instance to be launched as a replacement as soon as an instance transitions to UnreachableInactive