With that you have just moved the question to: how do they ensure that the metadata database is available _and_ strongly consistent at the same time for all the requests?
Because the metadata database is certainly also a distributed one, hence you need to query _all_ the nodes or can end up in a split-brain situation and lose consistency (or availability if you choose to down the system or a part of the system).
With that you have just moved the question to: how do they ensure that the metadata database is available _and_ strongly consistent at the same time for all the requests?
Because the metadata database is certainly also a distributed one, hence you need to query _all_ the nodes or can end up in a split-brain situation and lose consistency (or availability if you choose to down the system or a part of the system).