What Is High Availability?

High availability

AWS defines availability as “A system that is available is capable of delivering the designed functionality at a given point in time. Highly available systems are those that can withstand some measure of degradation while still remaining available.” $^6$

While scalability focuses on an amount of something to handle, availability is concerned with if functionality is delivered at all. Although both play hand in hand, availability should be a separate concern and might require different approaches to our architecture.

Example 1:

...