A global commercial aviation company is designing a new flight operations dispatch platfor… — AWS Certified Solutions Architect - Professional

A global commercial aviation company is designing a new flight operations dispatch platform. The application tier runs on Amazon EC2 instances in an Auto Scaling group behind an Application Load Balancer (ALB). The application requires outbound internet access to retrieve real-time weather feeds. Internal microservices communicate using a Private Hosted Zone (PHZ) named `dispatch.internal`. The database tier uses Amazon Aurora PostgreSQL. The primary deployment is in `us-east-1`. The company requires a disaster recovery (DR) architecture in `us-west-2` that is highly available across multiple Availability Zones in both regions. The DR plan must meet a Recovery Time Objective (RTO) of $15\text{ minutes}$ and a Recovery Point Objective (RPO) of $1\text{ minute}$ , while minimizing ongoing costs. During normal operations, all user traffic must be routed to `us-east-1`. Which design strategy meets these requirements?

A
Configure Aurora DB cluster copy tasks to take hourly snapshots in `us-east-1`, copy them to `us-west-2`, and restore them upon failover. In both regions, deploy NAT Gateways in each Availability Zone. Link the `dispatch.internal` Private Hosted Zone with the VPCs in both regions. Configure a Route 53 Latency routing policy with health checks to route users to the nearest healthy ALB. Set the `us-west-2` Auto Scaling group minimum capacity to $0$ to minimize costs.
B
Provision an Amazon Aurora Global Database with the primary cluster in `us-east-1` and a secondary cluster in `us-west-2`. In `us-east-1`, deploy NAT Gateways in each Availability Zone. In `us-west-2`, deploy one NAT Gateway in a single public subnet to minimize passive regional costs and route all outbound traffic from all private subnets through it. Link the `dispatch.internal` Private Hosted Zone with the VPCs in both regions. Configure a Route 53 Failover routing policy with an active record pointing to the `us-east-1` ALB and a passive record pointing to the `us-west-2` ALB, associated with Route 53 active health checks. Set the `us-west-2` Auto Scaling group minimum capacity to $2$ .
Provision an Amazon Aurora Global Database with the primary cluster in `us-east-1` and a secondary cluster in `us-west-2`. In both regions, deploy NAT Gateways in each Availability Zone used by the application. Link the `dispatch.internal` Private Hosted Zone with the VPCs in both regions. Configure a Route 53 Failover routing policy with an active record pointing to the `us-east-1` ALB and a passive record pointing to the `us-west-2` ALB, associated with Route 53 active health checks. Set the `us-west-2` Auto Scaling group minimum capacity to $2$ .Answer
D
Provision an Amazon Aurora Global Database with the primary cluster in `us-east-1` and a secondary cluster in `us-west-2`. In both regions, deploy NAT Gateways in each Availability Zone. Link the `dispatch.internal` Private Hosted Zone only with the `us-east-1` VPC, assuming internal DNS queries from the secondary region will transitively resolve over a cross-region VPC peering connection. Configure a Route 53 Failover routing policy with an active record pointing to the `us-east-1` ALB and a passive record pointing to the `us-west-2` ALB, associated with Route 53 active health checks. Set the `us-west-2` Auto Scaling group minimum capacity to $2$ .

Answer

The correct strategy uses Amazon Aurora Global Database for cross-region replication, deploys NAT Gateways in all Availability Zones of both regions, associates the internal Private Hosted Zone with both VPCs, uses Route 53 Failover routing with health checks, and configures the secondary Auto Scaling group with a minimum capacity of 2.

The correct strategy utilizes Amazon Aurora Global Database to achieve near-zero replication lag, satisfying the 1-minute RPO. The secondary database cluster can be promoted in less than 15 minutes, satisfying the RTO. Route 53 Failover routing ensures all traffic goes to the primary region under normal circumstances and automatically redirects to the backup region if the primary health checks fail. Deploying NAT Gateways in every Availability Zone in both regions prevents outbound connectivity from becoming a single point of failure in either region. Finally, associating the internal Private Hosted Zone with both VPCs ensures that microservices can resolve internal names regardless of which region is active.

Step-by-Step Solution

Evaluate the database replication strategy to satisfy the Recovery Point Objective (RPO) of

1\text{ minute}

and Recovery Time Objective (RTO) of

15\text{ minutes}

Amazon Aurora Global Database provides sub-second physical replication lag and allows secondary cluster promotion in under

15\text{ minutes}

. Snapshot-based restore options fail both constraints.

An RPO of

1\text{ minute}

necessitates continuous database replication, while an RTO of

15\text{ minutes}

makes snapshot restoration models too slow.

Analyze internal DNS name resolution behavior across AWS Regions.

Confirm that the internal Private Hosted Zone must be associated with VPCs in both regions, as Route 53 Private Hosted Zones do not automatically share resolution boundaries transitively over peered VPC networks.

Correct internal resolution of microservices in the secondary region requires explicit Private Hosted Zone association.

Ensure outbound connectivity infrastructure is highly available across Availability Zones.

Provision NAT Gateways in each Availability Zone of both regions rather than using a single NAT Gateway in the secondary region.

High availability requires removing single points of failure, meaning each active Availability Zone must have its own path to the internet.

Configure the DNS routing policy to ensure proper active-passive failover transitions.

Select Route 53 Failover routing with active health checks to direct all user traffic to the primary region during normal operations.

Latency-based routing does not guarantee a strict active-passive traffic flow as specified by the business constraints.

Key Concept

High Availability and Disaster Recovery Design

Estimated Time:3m 0s

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