An organization is designing a cloud architecture that must be fault-tolerant within a single region. The architect decides to deploy application instances in multiple Availability Zones (AZs). Which cloud characteristic is being leveraged?
Resource pooling allows the provider to serve multiple customers and distribute resources across AZs for fault tolerance.
Why this answer
Deploying application instances across multiple Availability Zones (AZs) within a single region leverages resource pooling, a key cloud characteristic. Resource pooling allows the cloud provider to aggregate compute, storage, and network resources from multiple physical locations (AZs) into a shared pool that can be dynamically allocated to tenants. By distributing instances across AZs, the architect ensures that if one AZ fails, the application remains available using resources from other AZs, directly utilizing the provider's pooled infrastructure.
Exam trap
CompTIA often tests the distinction between resource pooling and elasticity, where candidates mistakenly think distributing across AZs is about scaling (elasticity) rather than leveraging the provider's shared physical infrastructure (resource pooling).
How to eliminate wrong answers
Option B (Measured service) is wrong because it refers to the metering and billing of cloud resource usage (e.g., per-hour or per-GB charges), not the architectural placement of instances across AZs for fault tolerance. Option C (Elasticity) is wrong because elasticity describes the ability to automatically scale resources up or down based on demand, not the geographic or fault-isolated distribution of instances. Option D (On-demand self-service) is wrong because it describes the ability to provision resources without human interaction via a web portal or API, not the multi-AZ deployment strategy for high availability.