Glossary
Multi-region
A system runs in several geographic regions, so the failure of one region does not end the service, and users have shorter distances.
Multi-region is two different goals in one word: resilience and proximity. Proximity is often served by an edge cache. Resilience requires state to travel, and that is where it becomes expensive.
The decisive question is whether a failover happens automatically or whether a person decides. Both are defensible, but only one of them works at three in the morning without a phone call.
How you notice it
- A region outage would end the business day.
- Users sit on several continents.
- There is a second region that has never carried load.
Frequently asked
What does multi region really cost?
More than twice the infrastructure, because state has to travel too. Cross region transfer, replication and doubled operational work come on top. For proximity to users alone a CDN does the job at a fraction of the cost.