An enterprise runs a critical containerized business API across two AWS accounts in an AWS Organization. The production environment is deployed in Account A within a VPC in the us-west-2 Region. The API runs on Amazon ECS tasks on AWS Fargate behind an Application Load Balancer (ALB). The data layer uses an Amazon Aurora PostgreSQL Global Database with the primary cluster in us-west-2 (Account A) and a secondary cluster in us-east-1 (Account B). A Route 53 Private Hosted Zone (PHZ) for api.internal is hosted in Account A and associated with the production VPC to allow internal services to resolve the backend API. The enterprise wants to establish a disaster recovery (DR) environment in us-east-1 (Account B) using a warm standby pattern to achieve an RTO of less than 15 minutes and an RPO of less than 1 minute. The DR environment must also run on ECS Fargate behind an ALB. The Fargate tasks in the DR environment require highly reliable outbound internet access to communicate with third-party payment gateways. Additionally, internal microservices in the DR environment must be able to resolve api.internal to the local DR load balancer during a failover. Which solution meets these requirements while adhering to AWS high availability and disaster recovery best practices?
- Promote the Aurora secondary cluster in us-east-1 to primary. Associate the Account A Private Hosted Zone for api.internal with Account B's VPC in us-east-1 using cross-account authorization and association. In Account B, configure a local ALB, create a Route 53 failover record for api.internal pointing to the local ALB, and associate it with a Route 53 health check based on a CloudWatch metric alarm that monitors ALB target health. Deploy NAT Gateways in each Availability Zone of Account B's VPC in us-east-1 to provide redundant outbound connectivity.Answer
- BPromote the Aurora secondary cluster in us-east-1 to primary. Rely on AWS Organizations default sharing behavior to automatically resolve api.internal in Account B's VPC. In Account B, configure a local ALB, create a Route 53 failover record for api.internal pointing to the local ALB, and associate it with a Route 53 health check based on a CloudWatch metric alarm that monitors ALB target health. Deploy NAT Gateways in each Availability Zone of Account B's VPC in us-east-1 to provide redundant outbound connectivity.
- CPromote the Aurora secondary cluster in us-east-1 to primary. Associate the Account A Private Hosted Zone for api.internal with Account B's VPC in us-east-1 using cross-account authorization and association. In Account B, configure a local ALB, create a Route 53 failover record for api.internal pointing to the local ALB, and associate it with a Route 53 health check based on a CloudWatch metric alarm that monitors ALB target health. Deploy a single NAT Gateway in one Availability Zone of Account B's VPC in us-east-1 and update the route tables of all private subnets across all zones to point to this single NAT Gateway.
- DPromote the Aurora secondary cluster in us-east-1 to primary. Associate the Account A Private Hosted Zone for api.internal with Account B's VPC in us-east-1 using cross-account authorization and association. In Account B, configure a local ALB and create a Route 53 failover record for api.internal pointing to the local ALB. Omit Route 53 health checks on the failover records, relying instead on Route 53 Resolver rules to automatically redirect traffic to the secondary region if the primary region's ALB becomes unreachable.