Geo Routing for Global AI Inference

Question

Pulumi · Accepted Answer

Geo Routing is a powerful feature that allows you to direct traffic to different endpoints based on the geographic location of the source request. This can be particularly useful when deploying a global AI inference service, as it ensures that users are served from the nearest geographic location, thereby minimizing latency and potentially improving service response times.

In a cloud environment like Google Cloud Platform (GCP), you can use Google Cloud DNS along with HTTP(S) Load Balancers to achieve geo-based routing. The Load Balancer can be configured to use a URL map that directs traffic based on the geographical origin of the incoming requests.

Here's how you might set up such a system using Pulumi:

- Use the `gcp.dns.ResponsePolicyRule` resource to create DNS policies that can direct traffic based on geolocation.
- Set up one or more `google-native.compute/alpha.GlobalForwardingRule` resources to handle incoming traffic and forward requests based on the URL map.
- Define `google-native.compute/alpha.UrlMap` resources that associate specified paths and host rules with the appropriate backend services or backend buckets for AI inference endpoints.
- Create `google-native.compute/alpha.BackendService` resources for the AI inference services you deploy in various regions.
- Implement backend services with autoscaling enabled and link them to instance groups with `google-native.compute/alpha.RegionInstanceGroupManager` to handle your AI inference workloads.

Let's see how this would look in a Pulumi Python program. Remember that this will be a general outline, and the specific implementation details, such as precise backend service configurations and instances, would depend on your actual AI inference application and architecture.

```python
import pulumi
import pulumi_gcp as gcp

# Define a DNS policy that directs traffic based on geolocation
dns_policy = gcp.dns.ResponsePolicy("geo-routing-policy", 
    rules=[
        gcp.dns.ResponsePolicyRuleArgs(
            dns_name="ai-inference.yourdomain.com.",
            behavior="geo",
            geo_targets=["US", "EU"],
            response_policy="your-response-policy-id",
            # Local data configuration would go here
        )
    ],
)

# Configure global forwarding rules to direct traffic appropriately
global_forwarding_rule = google_native.compute.v1.GlobalForwardingRule("global-forwarding-rule",
    name="global-forwarding-rule",
    # ...additional parameters like ip version, ip address, etc.
)

# Define a URL map for the HTTP(S) Load Balancer
url_map = google_native.compute.v1.UrlMap("url-map",
    name="url-map",
    default_service="global-backend-service",  # Assuming this is your default backend service
    # Add host rules, path matchers, etc.
)

# Setup a Backend Service for the AI infrastructure in a particular region
backend_service = google_native.compute.v1.BackendService("backend-service",
    name="global-backend-service",
    backends=[
        # Define backends such as instance groups in various regions
        google_native.compute.v1.BackendServiceBackendArgs(
            group="instance-group-url",  # The URL for the instance group
            # Other backend configurations
        ),
    ],
    # Additional parameters for health checks, policies, etc.
)

# Ensure the backend services are linked to instance groups with instance templates that define the AI inference setup.
# This will involve creating instance templates and instance group managers for each geographic region.

# The code for setting up instance templates and group managers has been omitted for brevity.

# Setup a health check for the backend services
health_check = google_native.compute.v1.HealthCheck("health-check",
    name="backend-service-health-check",
    # Configure the appropriate health check parameters for your service
)

# Outputs can be used to export the DNS name, forwarding IP, and other relevant data
pulumi.export('dns_name', dns_policy.dns_name)
# Remember to export other values you might want to retrieve from the stack
```

In this outline, we are creating a geolocation-based DNS rule that directs traffic to the `ai-inference.yourdomain.com` subdomain based on geographic location. We then setup a global forwarding rule and a corresponding URL map to route the traffic to the appropriate backend service. Backend services are linked to instance groups, which can be regional and tailored for your AI inference applications, and the services are health-checked to ensure that only healthy instances serve traffic.

You'll want to flesh this out with exact details of your instance configurations, health checks, and the precise routing rules you'll need for your AI inference setup, but this should provide a solid foundation for building out your globally distributed inference service with Geo Routing.