Today, we are announcing the public preview offering for Manual failover. This feature is part of IoT Hub cloud service and allows customers to failover an IoT hub instance from its primary Azure region to its corresponding geo-paired region.
Failures are possible in any software system especially when it's a distributed system and it is important to plan for failures. The IoT Hub service implements redundancies at various layers of its implementation to safeguard its customers against transient failures and failures scoped within a datacenter. The service offers a high level of SLA using these redundancies. However, region wide failures or extended outages, although remote are still possible.
Read about it in the Azure blog.