Multi-Region AI Services Failover Using DNS Records

Question

Pulumi · Accepted Answer

To accomplish multi-region failover for AI services using DNS records, we'll need to utilize DNS records that can direct traffic based on geography or availability. This is done by setting up DNS routing policies, such as latency-based routing, geolocation routing, or failover routing.

Here's an approach one might take using Pulumi to create DNS records with latency-based routing policies, using AWS Route 53:

1. We will create multiple AI service endpoints in different AWS regions.
2. We will set up a hosted zone in AWS Route 53.
3. We will create DNS records with a latency-based routing policy in that hosted zone for each AI service endpoint.

Latency-based routing allows Route 53 to route user requests to the region that provides the lowest latency. If one of the services fails or becomes unavailable, Route 53 can re-route traffic to the healthy endpoints with the lowest latency.

Below is a Pulumi program written in Python that sets up such a configuration:

```python
import pulumi
import pulumi_aws as aws

# Replace these variables with your desired domains and AI service endpoint information.
ai_service_domain = "ai-service.example.com"
ai_service_endpoints = {
    "us-west-1": "us-west-1-endpoint.example.com",
    "us-east-1": "us-east-1-endpoint.example.com",
    # ... Add other regional endpoints as necessary
}

# Create a new hosted zone for your AI service domain.
zone = aws.route53.Zone("ai-service-zone", name=ai_service_domain)

# For each service endpoint, create a record with latency routing policy.
for region, endpoint in ai_service_endpoints.items():
    aws.route53.Record(f"ai-service-latency-record-{region}",
                       zone_id=zone.zone_id,
                       name=ai_service_domain,
                       type="CNAME",
                       set_identifier=region,
                       latency_routing_policy=aws.route53.RecordLatencyRoutingPolicyArgs(
                           region=region),
                       records=[endpoint],
                       ttl=300)

# Export the Hosted Zone ID
pulumi.export('hosted_zone_id', zone.zone_id)
```

### Explanation

- We import the necessary modules: `pulumi` and `pulumi_aws`.
- We define our AI service domain and the endpoints for each region as variables.
- We create an AWS Route 53 hosted zone for our AI service domain, which will contain our DNS records.
- We loop through our endpoints to create `CNAME` records in the hosted zone for each regional AI service endpoint. By specifying `latency_routing_policy`, each record is configured to route traffic based on latency automatically.
- We export the hosted zone ID to allow interacting with it outside of Pulumi if required.

Make sure you replace the `ai_service_domain` and `ai_service_endpoints` variables with the actual domain and endpoint information for your AI services.

To apply this Pulumi program:

- Ensure you have Pulumi installed and configured with appropriate AWS access.
- Save this program in a file named `__main__.py`.
- Run `pulumi up` to deploy your changes.
- After deployment, Route 53 will manage the traffic to your AI services based on latency automatically.

Keep in mind that you may need to expand on this program depending on your specific requirements, such as adding health checks or dealing with more complex routing policies.