An enterprise manages its applications using a multi-account AWS Organizations structure. … — AWS Certified Solutions Architect - Professional

An enterprise manages its applications using a multi-account AWS Organizations structure. A critical multi-tier application has its primary deployment in the us-east-1 Region under a Production Account, and its disaster recovery (DR) environment in the us-west-2 Region under a DR Account. The database tier consists of an Amazon Aurora PostgreSQL Global Database, with the primary cluster in us-east-1 and a secondary cluster in us-west-2. The enterprise has a target Recovery Time Objective (RTO) of $15$ minutes. During a recent DR drill, the solutions architect identified the following issues:
1. Internal microservices running in the us-west-2 VPC could not resolve the DNS names of internal dependencies defined in the Route 53 Private Hosted Zone (PHZ) hosted in the us-east-1 Production Account.
2. The database failover took longer than the RTO because it required manual database promotion and manual updates to the database connection string in the application configuration.

Which TWO actions should the solutions architect take to resolve these issues and meet the RTO? (Select TWO.)

Create a VPC association authorization for the us-west-2 VPC in the primary Production Account, and then associate the us-west-2 VPC with the Route 53 Private Hosted Zone using the AWS CLI or SDK from the DR Account.Answer
Create a Route 53 CNAME record with a low Time to Live (TTL) of $10$ seconds pointing to the active Aurora regional cluster endpoint, and write an AWS Lambda function triggered by Amazon EventBridge to automate the promotion of the secondary Aurora cluster and update the CNAME record during a failover event.Answer
C
Re-create the Route 53 Private Hosted Zone in the DR Account with the same domain name, and configure Route 53 latency-based routing to resolve the internal service names across both regions.
D
Configure Route 53 active-passive failover routing records pointing directly to the regional Aurora database cluster endpoints, and associate them with Route 53 health checks configured to monitor database port $5432$ over the public internet.
E
Implement a pilot light disaster recovery strategy in us-west-2 where application servers are kept shut down and database backups are restored from Amazon S3 on-demand during a failover to minimize running costs.

Answer

The correct answer states that you must authorize and associate the Route 53 Private Hosted Zone from the Production Account with the VPC in the DR Account, and automate the Aurora Global Database failover and Route 53 CNAME updates using AWS Lambda and EventBridge.

To resolve the internal DNS resolution issue, a VPC association authorization must be created in the account hosting the Route 53 Private Hosted Zone (Production Account), followed by associating the VPC in the DR Account with that hosted zone. To automate the database failover and meet the

15

-minute RTO, the Solutions Architect should automate database promotion using the Aurora Global Database managed failover API via Lambda and EventBridge, and map the application database connection strings to a Route 53 CNAME record with a short TTL that points to the active regional cluster endpoint.

Step-by-Step Solution

Authorize VPC association across accounts

The Route 53 Private Hosted Zone in the Production Account permits association from the DR Account's VPC.

Before a Private Hosted Zone can be associated with a VPC in a different AWS account, the owner of the hosted zone must explicitly authorize the association.

Associate the secondary VPC with the Private Hosted Zone

Internal DNS records in the Private Hosted Zone resolve correctly within the secondary VPC in us-west-2.

This establishes cross-account private DNS resolution so that secondary microservices can locate dependencies.

Create an EventBridge rule and Lambda function for database failover orchestration

Automated promotion of the secondary Aurora database cluster during failovers.

Manual database promotion is too slow and violates the

15

-minute RTO; automation is required to meet the goal.

Configure a low-TTL CNAME record pointing to the active regional Aurora writer endpoint

Applications dynamically resolve the active writer endpoint within seconds after failover without manual config updates.

Low TTL prevents DNS caching delays and eliminates the need to update database connection strings on the application servers.

Key Concept

Cross-account Route 53 Private Hosted Zone association and automated database DR failover orchestration.

Question

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

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