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Difficulty: MediumAmazon Route 53 DNS Configuration and Routing Policies

A SysOps Administrator is configuring active-passive DNS failover in Amazon Route 53 for a serverless application. The application is hosted on Amazon API Gateway (regional endpoint) under the zone apex domain name (example.com). The primary API is deployed in the us-east-1 region, and the standby API is deployed in the us-west-2 region. If the primary API becomes unavailable, traffic must automatically fail over to the standby API. Which two actions must the administrator take to configure this routing? (Select TWO.)

  1. Create a Route 53 health check to monitor the health of the primary API Gateway regional endpoint.Answer
  2. Create an Alias A record for example.com using the Failover routing policy, set the failover type to Primary, point it to the us-east-1 API Gateway custom domain, and associate it with the created Route 53 health check.Answer
  3. C
    Create a CNAME record for example.com pointing to the us-east-1 API Gateway regional endpoint, and configure it with the Failover routing policy.
  4. D
    Create an Alias A record for example.com pointing to the us-east-1 API Gateway custom domain, set the routing policy to Failover, and enable the Evaluate Target Health option.
  5. E
    Create an Alias A record for example.com using the Failover routing policy, set the failover type to Secondary, point it to the us-west-2 API Gateway custom domain, and associate it with the primary Route 53 health check.

Answer

Create a Route 53 health check to monitor the health of the primary API Gateway regional endpoint, and create an Alias A record for example.com using the Failover routing policy, set the failover type to Primary, point it to the us-east-1 API Gateway custom domain, and associate it with the created Route 53 health check.
To set up active-passive failover at the zone apex (example.com) for API Gateway, the administrator must use Alias A records because CNAME records are not permitted at the zone apex. Because Route 53 does not support the 'Evaluate Target Health' option for API Gateway custom domains, a separate Route 53 health check must be created to monitor the primary endpoint. The primary Failover record is then associated with this health check to enable automatic failover. The secondary record does not require this health check.

Step-by-Step Solution

1
Identify the domain requirement and choose the record type.
Since the domain is at the zone apex (example.com), a CNAME record cannot be used. An Alias A record must be configured to point to the API Gateway custom regional domain.
DNS RFCs prohibit CNAME records at the zone apex.
2
Determine how Route 53 monitors API Gateway health.
Route 53's 'Evaluate Target Health' is not supported for API Gateway alias targets. A custom Route 53 health check must be created to monitor the availability of the primary endpoint.
API Gateway does not natively integrate with Route 53's automatic target health evaluation.
3
Configure the primary and secondary Failover records.
Create the primary Alias A record pointing to the primary API and associate it with the custom health check. Create the secondary Alias A record pointing to the standby API without associating the primary's health check.
This establishes the active-passive failover mechanism, ensuring traffic is redirected to the standby API only when the primary fails.

Key Concept

Amazon Route 53 Failover Routing with API Gateway Alias Targets at the Zone Apex
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Topics

Amazon Route 53 DNS Configuration and Routing Policies

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