Explanation
For high availability requirements, deploying an application across multiple Availability Zones (AZs) is the correct approach because:
- Availability Zones are physically separate data centers within an AWS Region
- Each AZ has independent power, cooling, and networking
- Deploying across multiple AZs provides fault tolerance - if one AZ fails, the application can continue running in other AZs
- This architecture ensures high availability and resilience
Why other options are incorrect:
- Single Availability Zone: Provides no redundancy - if that AZ fails, the entire application goes down
- AWS Direct Connect: This is for dedicated network connectivity, not for high availability deployment
- Reserved Instances: This is a billing/pricing model for cost savings, not a deployment strategy for high availability
High availability in AWS is achieved through multi-AZ deployments, which is a fundamental cloud architecture principle.