
Explanation:
Box 1: Azure Traffic Manager
Project1: The development of an app hosted on multiple Azure virtual machines that are configured as a Windows Server failover cluster Maintain availability if an Azure region fails.
RTO 45 seconds
Azure Traffic Manager protects against region failures.
How fast does Traffic Manager move my users away from an unhealthy endpoint?
By using the settings below, Traffic Manager can provide failovers under 10 seconds after an endpoint goes unhealthy and a DNS query is made against the corresponding profile.
Box 2: Availability zones
Project2: The development of an app hosted on multiple Azure virtual machines that run Ubuntu Maintain availability if an Azure datacenter fails.
RTO 5 minutes.
Availability zone protects against Datacenter failures, and can be configure to provide an RTO of less than 5 minutes.
Box 3: Azure Site Recovery
Project3: The development of an app hosted on a single Azure virtual machine that runs Windows Server Maintain availability during datacenter maintenance events.
RTO 2 hours.
You can recover your Azure Virtual Machines against outages by using Azure Site Recovery. In the event of an outage, you can recover to either the secondary availability zone or the secondary Azure region, with a RPO (Recovery Point Objective) of approximately 5 minutes and an RTO (Recovery Time Objective) of less than 1 hour.
Reference:
https://learn.microsoft.com/en-us/azure/traffic-manager/traffic-manager-faqs
https://techcommunity.microsoft.com/blog/azurestorageblog/protecting-azure-vm-against- zonalregional-outages-using-azure-site-recovery-and-/4033280