Datadog APM can create inferred spans for requests that pass through Azure API Management to your backend services. The spans enable end-to-end traces, service maps, and sampling based on the API Management gateway.

Inferred spans for Azure API Management are supported for .NET, JavaScript (Node.js), and Python only. Other runtimes (for example Go, Java, or PHP) do not emit Azure API Management inferred spans, even if they support inferred spans for other gateways.

Prerequisites

• DD_TRACE_INFERRED_PROXY_SERVICES_ENABLED=true is set in your application settings.
• Your backend uses a supported runtime, minimum tracer version, and web framework from the table below.

Supported runtimes and web frameworks

Setup

To create inferred spans, Azure API Management must pass the following headers to your backend services:

Inbound policy

Add the following policy to the inbound section of your API in Azure API Management so these headers are set on requests to your backend:

<set-header name="x-dd-proxy" exists-action="override">
    <value>azure-apim</value>
</set-header>
<set-header name="x-dd-proxy-request-time-ms" exists-action="override">
    <value>@(new DateTimeOffset(context.Timestamp).ToUnixTimeMilliseconds().ToString())</value>
</set-header>
<set-header name="x-dd-proxy-httpmethod" exists-action="override">
    <value>@(context.Operation.Method)</value>
</set-header>
<set-header name="x-dd-proxy-path" exists-action="override">
    <value>@(context.Operation.UrlTemplate)</value>
</set-header>
<set-header name="x-dd-proxy-region" exists-action="override">
    <value>@(context.Deployment.Region)</value>
</set-header>
<set-header name="x-dd-proxy-domain-name" exists-action="override">
    <value>@(context.Request.OriginalUrl.Host)</value>
</set-header>

You can add this policy at the API level in the Azure portal under API Management > your API > Design → Inbound processing → Code view (see Set or edit Azure API Management policies), using the Azure API Management REST API, or policies in your API definition.

Update sampling rules

Head-based sampling still applies when using Azure API Management tracing. Because the inferred span becomes the new trace root, update your rules so the service value matches the API Management service name shown in Datadog.

For example, if the original sampling rule is:

DD_TRACE_SAMPLING_RULES='[{"service":"my-backend","sample_rate":0.5}]'

Update the rule so the service value matches your API Management API name as it appears in Datadog, or remove the service key to apply the rule to all root spans:

DD_TRACE_SAMPLING_RULES='[{"service":"my-azure-apim-api","sample_rate":0.5}]'

Or apply to all root spans:

DD_TRACE_SAMPLING_RULES='[{"sample_rate":0.5}]'

Further Reading

お役に立つドキュメント、リンクや記事:

Azure integrationsDOCUMENTATION Ignoring Unwanted Resources in APMDOCUMENTATION Trace Context PropagationDOCUMENTATION