Which solution will meet these requirements?
In Route 53 ARC, create a new assertion safety rule. Apply the assertion safety rule to the two routing controls. Configure the rule with the ATLEAST type with a threshold of 1.
In Route 53 ARC, create a new gating safety rule. Apply the assertion safety rule to the two routing controls. Configure the rule with the OR type with a threshold of 1.
In Route 53 ARC, create a new resource set. Configure the resource set with an AWS::Route53::HealthCheck resource type. Specify the ARNs of the two routing controls as the target resource. Create a new readiness check for the resource set.
In Route 53 ARC, create a new resource set. Configure the resource set with an AWS::Route53RecoveryReadiness::DNSTargetResource resource type. Add the domain names of the two Route 53 alias DNS records as the target resource. Create a new readiness check for the resource set.
Explanations:
Creating an assertion safety rule with the ATLEAST type ensures that at least one routing control must be turned on. This type of rule will not allow both routing controls to be off simultaneously, thereby satisfying the requirement.
A gating safety rule with the OR type would allow either routing control to be turned off without requiring at least one to be on. This does not meet the company’s requirement of having at least one routing control enabled at all times.
Configuring a resource set with an AWS::Route53::HealthCheck does not directly enforce the requirement for the routing controls. Health checks are used to monitor the health of resources but do not control the state of routing controls themselves.
While creating a resource set with an AWS::Route53RecoveryReadiness::DNSTargetResource can help with readiness checks, it does not enforce the requirement to keep at least one routing control enabled. This option does not provide the necessary mechanism to ensure that at least one control is on.
It appears that the answer is:
In Route 53 ARC, create a new assertion safety rule. Apply the assertion safety rule to the two routing controls. Configure the rule with the ATLEAST type with a threshold of 1.