CompTIA Cloud Essentials+ (CLO-002)Cloud ConceptsMedium
A cloud architect is designing a highly available application. The design includes deploying application instances across multiple availability zones within a single cloud region. This strategy aims to protect the application from which type of failure?
- AData center-wide outage
- BSingle instance failure
- CTotal regional outage
- DApplication-level software bug
Show answer & explanationAnswer & explanation
Correct answer: A. Data center-wide outage
Availability Zones are physically distinct, independent data centers within a region. Deploying across multiple zones protects against a single data center-wide outage by allowing the application to continue running in other zones.
Why the other options are wrong
- B. While it helps, deploying across multiple zones primarily addresses data center failures, not just individual instance failures which can be handled by auto-scaling groups within a single zone.
- C. Deploying across availability zones within a *single* region does not protect against a total regional outage. For that, multi-region deployment is needed.
- D. Application-level software bugs are addressed through coding practices, testing, and rollback strategies, not by infrastructure deployment across zones.
Availability Zone (AZ)
One or more discrete data centers with redundant power, networking, and connectivity, housed in a cloud region. They are physically separated to protect against single points of failure.
- Independent data centers within a cloud region.
- Designed for fault isolation, protecting against data center failures.
- Connected by low-latency links within the region.
Memory trick: Regions are countries, AZs are cities, instances are buildings.