High availability and disaster recovery solve different problems
High availability handles a component failing. Disaster recovery handles the site, region or platform being gone.
They are frequently conflated, and the conflation is expensive: organisations with excellent failover discover it does not help when the problem is corruption replicated instantly to the standby, or a compromised account acting on both. Different failure, different answer.
More on Resilience
- A dependency can be more critical than the applicationThe lighter side goes down
- Manual workarounds have capacity limitsThe pipe gets narrower
- Recovery priorities should follow business outcomesWhose order is it?
- Resilience includes people and suppliersThe shelf runs out
- Failover can fail if never exercisedThe day it is asked
- Graceful degradation preserves the important partDrop the ballast