Distributed Tracing for Durable Functions and general OTel support compatibility

[erwinkramer]

Question

1. a. Distributed Tracing exists for Durable Functions, which is compatible with OTel. How compatible is it with the general OTel support in Azure Functions, as being tracked here: OpenTelemetry support in Azure Functions #10665?

   b. I've found samples/DistributedTraceSample/OpenTelemetry#tracer-provider which seems more aligned with the general OTel support, would that be the preferred - equivalent - setup, compared to just setting "distributedTracingEnabled": true, in host.json?

2. Shouldn't the Distributed Tracing functionality for durable functions be mentioned here https://learn.microsoft.com/en-us/azure/azure-monitor/app/opentelemetry?

[erwinkramer]

It seems to just work nicely together, at least in the simplest form (ignore the references to DurableFunctionsMonitor, that's not needed in this case).

This is my startup program.cs:

var builder = new HostBuilder();

builder.ConfigureFunctionsWebApplication((builderContext, workerAppBuilder) =>
{

    workerAppBuilder.UseDurableFunctionsMonitor();
});

builder.ConfigureServices(services =>
{
    services.AddOpenTelemetry()
    .WithTracing(builder =>
    {
        builder.AddSource(nameof(HelloOrchestration)); //register for the CreateReplaySafeLogger found in HelloOrchestration.cs
    })
    .UseFunctionsWorkerDefaults()
    .UseAzureMonitorExporter();
});

builder.Build().Run();

I had to do the AddSource because otherwise the log information of the CreateReplaySafeLogger wouldn't pop up:

ILogger logger = context.CreateReplaySafeLogger(nameof(HelloOrchestration));

My host.json:

{
  "version": "2.0",
  "telemetryMode": "OpenTelemetry",
  "logging": {
    "applicationInsights": {
      "samplingSettings": {
        "isEnabled": false,
        "excludedTypes": "Request"
      },
      "enableLiveMetricsFilters": true
    }
  },
  "extensions": {
    "durableTask": {
      "tracing": {
        "distributedTracingEnabled": true,
        "version": "V2"
      },
      "storageProvider": {
        "type": "AzureStorage"
      }
    }
  }
}

And finally, my csproj:

    <FrameworkReference Include="Microsoft.AspNetCore.App" />
    <PackageReference Include="Azure.Monitor.OpenTelemetry.Exporter" Version="1.4.0" />
    <PackageReference Include="DurableFunctionsMonitor.DotNetIsolated" Version="6.7.1" />
    <PackageReference Include="Microsoft.Azure.Functions.Worker" Version="2.0.0" />
    <PackageReference Include="Microsoft.Azure.Functions.Worker.OpenTelemetry" Version="1.1.*-*" />
    <PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.DurableTask" Version="1.6.1" />
    <PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Http" Version="3.3.0" />
    <PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Http.AspNetCore" Version="2.0.2" />
    <PackageReference Include="Microsoft.Azure.Functions.Worker.Sdk" Version="2.0.5" />