Does AtalasDB need to run on the same instances as the datastore, or can it run external to the store and, for example, connect to a managed cloud service such

Does AtalasDB need to run on the same instances as the datastore, or can it run external to the store and, for example, connect to a managed cloud service such as Google's new Cloud Bigtable (https://cloud.google.com/bigtable/docs/ https://cloud.google.com/bigtable/docs/)?