When something fails, what's going to happen?

This is the key question of any deployment, because it matters. Consider applications like WhatsApp; if they go down, even for a minute, then the user base is going to go crazy. With your application, too, if the system fails, then you are going to lose users but, more importantly, you are also going to lose your reputation.

Cosmos DB is a managed database provider and I believe that they care about failover a lot. There are generally two ways to handle failover:

• Automatic failover
• Manual failover

Let's discuss each of them.