Hosting on anything/anywhere really. Even if one builds clusters with true 100% reliability running on nuclear power buried 100 feet underground, you still have to talk to the rest of the world through a network which can fall apart for variety of reasons. If most of your users are on their mobile phones, they might not even notice outages.
At some point adding an extra 9 to the service availability can no longer be justified for the associated cost.
Hosting on anything/anywhere really. Even if one builds clusters with true 100% reliability running on nuclear power buried 100 feet underground, you still have to talk to the rest of the world through a network which can fall apart for variety of reasons. If most of your users are on their mobile phones, they might not even notice outages.
At some point adding an extra 9 to the service availability can no longer be justified for the associated cost.