Latency Reduction for AI APIs via Azure Front Door

Question

Pulumi · Accepted Answer

In order to reduce latency for AI APIs hosted on Azure, you can use Azure Front Door, which is a scalable and secure entry point for fast delivery of your global applications. Azure Front Door provides features such as SSL offloading, path-based routing, fast failover, and global load balancing which are essential for optimizing the performance of API services.

Below, I will guide you through creating an Azure Front Door configuration using Pulumi to achieve lower latency for your AI APIs. The configuration will include setting up a Front Door, a Backend Pool with your API as the backend, and a Routing Rule to direct traffic to that backend pool.

Here is how each resource contributes to reducing latency:

1. **Front Door**: Acts as the global entry point for your API traffic. It uses Microsoft's global network to ensure that user requests are routed to the nearest Front Door point of presence.

2. **Backend Pool**: Contains your API endpoints. Front Door will route traffic to these endpoints based on rules you define and the health of these endpoints.

3. **Routing Rule**: Defines a set of criteria for how incoming traffic to the Front Door is handled and routed to the backend pool. It includes the path for the API and the protocols allowed.

Here is a Pulumi program that sets up these resources on Azure:

```python
import pulumi
import pulumi_azure_native as azure_native

# Create an Azure resource group for your application's resources
resource_group = azure_native.resources.ResourceGroup('resource-group')

# Create an Azure Front Door profile
front_door_profile = azure_native.cdn.Profile(
    "front-door-profile",
    resource_group_name=resource_group.name,
    sku=azure_native.cdn.SkuArgs(
        name="Premium_AzureFrontDoor"  # Choose an appropriate SKU for your needs
    ),
    location="global"  # Azure Front Door is a global service
)

# Create a Backend Pool with your API endpoint
backend_pool = azure_native.cdn.BackendPool(
    "backend-pool",
    resource_group_name=resource_group.name,
    profile_name=front_door_profile.name,
    backends=[
        azure_native.cdn.BackendArgs(
            address="api.example.com",  # Replace with the address of your API
            http_port=80,
            https_port=443,
            priority=1,
            weight=50,
            backend_host_header="api.example.com"  # Must match the 'address' value or the domain to which the API resolves
        )
    ]
)

# Create a Routing Rule
routing_rule = azure_native.cdn.RoutingRule(
    "routing-rule",
    resource_group_name=resource_group.name,
    profile_name=front_door_profile.name,
    frontend_endpoints=[
        # Link the rule with the default frontend endpoint for your profile
        azure_native.cdn.FrontendEndpointLinkArgs(
            id=front_door_profile.id.apply(lambda id: f"{id}/frontendEndpoints/defaultEndpoint")  # Building the frontend endpoint ID dynamically
        )
    ],
    accepted_protocols=[
        "Https"  # Assuming API is served over HTTPS
    ],
    patterns_to_match=["/*"],  # This pattern will match any path, modify this according to your API paths
    route_configuration=azure_native.cdn.ForwardingConfigurationArgs(
        forwarding_protocol="HttpsOnly",  # Redirect all HTTP traffic to HTTPS
        backend_pool=azure_native.cdn.SubResourceArgs(
            id=backend_pool.id  # Link to your backend pool
        )
    )
)

# Export the Front Door endpoint URL so you can easily access it
pulumi.export("front_door_url", front_door_profile.endpoint)
```

When you run this Pulumi program, it will provision the necessary Azure resources to set up Azure Front Door for your AI APIs. Once this setup is complete, it will provide you with a URL endpoint for Azure Front Door, which will be the new entry point for your API clients. Requests to this URL will be automatically routed through Azure's global network infrastructure, reducing the latency for users around the world.

Remember to replace `"api.example.com"` with the actual address of your API and adjust the `patterns_to_match` and `forwarding_protocol` fields based on the specifics of your application and how you want to manage your traffic.

Please note that this is a basic setup and Azure Front Door offers a plethora of features that can further optimize and secure your global application delivery. You can explore additional settings such as custom domains, SSL offloading, URL rewrites, caching rules, and more to tailor the service to your precise use case.