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Difficulty: MediumOptimizing Network Performance and Latency

An enterprise hosts a high-throughput, latency-sensitive application across three Availability Zones in the us-west-2 Region. The application relies on external API endpoints for real-time payment processing and needs to resolve internal microservice endpoints hosted in a separate shared services VPC. The application is experiencing intermittent latency spikes and connection timeouts during peak hours. An audit reveals that all outbound traffic to the internet-facing payment gateway is routed through a single NAT Gateway in the primary Availability Zone, and internal microservice DNS queries are failing to resolve. Which of the following actions should the Solutions Architect take to optimize the network performance and resolve these latency and DNS issues? (Select TWO.)

  1. Deploy a NAT Gateway in each Availability Zone and update the route tables of the private subnets to point to the local NAT Gateway in their respective zones.Answer
  2. Associate the Route 53 Private Hosted Zone of the shared services VPC with the application VPC.Answer
  3. C
    Consolidate all outbound routing by directing traffic from all private subnets across all Availability Zones to a single NAT Gateway located in the primary Availability Zone to avoid cross-AZ replication overhead.
  4. D
    Recreate the microservice DNS records in a new public Route 53 hosted zone and configure the application VPC DHCP options set to resolve queries via public DNS servers.
  5. E
    Submit a support ticket to AWS to pre-warm the Application Load Balancers (ALBs) to prevent TCP connection timeouts during outbound API calls.

Answer

Deploy a NAT Gateway in each Availability Zone and update the route tables of the private subnets to point to the local NAT Gateway in their respective zones; Associate the Route 53 Private Hosted Zone of the shared services VPC with the application VPC.
The correct architecture deploys a NAT Gateway in each Availability Zone so that outbound traffic to the payment gateway does not traverse Availability Zones, reducing latency and removing a single point of failure. Additionally, associating the Route 53 Private Hosted Zone of the shared services VPC with the application VPC allows the application instances to resolve internal microservice endpoints directly and successfully.

Step-by-Step Solution

1
Analyze the outbound traffic path to external APIs and identify the latency bottleneck.
The application routes all outbound internet traffic through a single NAT Gateway in one Availability Zone, resulting in cross-AZ network latency and a single point of failure.
To optimize outbound network latency and improve reliability, outbound traffic should remain within the local Availability Zone by deploying a NAT Gateway in each zone.
2
Analyze the DNS resolution failure for internal microservice endpoints.
The Route 53 Private Hosted Zone containing the microservice DNS records is in a shared services VPC and has not been associated with the application VPC.
Associating the Private Hosted Zone with the application VPC enables direct and successful resolution of internal endpoints.

Key Concept

Multi-AZ network path optimization and cross-account DNS resolution using Route 53 Private Hosted Zone association.
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Topics

Optimizing Network Performance and Latency