Comment by solatic

> That means that when a maintenance event occur on your insaance, AWS will start a new instance in a new zone, and fail over to that one.

Not true for single-AZ deployments. There is downtime during the maintenance event, but this is also true in multi-AZ deployments when the instance in the second AZ is promoted; a multi-AZ maintenance window has slightly less downtime, but not much; downtime is downtime, but generally not enough to affect a 99.9% SLA anyway.

> EC2 On-Demand Capacity Reservations

Also quite expensive to maintain just for outage recovery events.

The point I'm trying to make is that formal risk analysis forces you to think about actual sources of risk, and SRE/FinOps principles force you think about how much budget you are willing to spend to address those risks. And I don't understand how a tool like this fits into formal risk analysis and where it presents an optimum solution for those risks.