content of operation_ParentId in application insights using W3C - azure

Question

I'm currently using an .NET 6.0 isolated function with an HTTP trigger.
Because the activity is not being filled, I've added a middleware that creates the activity based on the W3C traceparent header.
My expectation based on MS docs is that when using Application Insights, the operation_ParentId would relate directly to the ParentSpanId of an Activity where logging is done.
Yet that is not what I'm seeing. What I'm seeing is following
Application A sends a request using traceparent = 00-3abe9f15e940badc5f1521e6eb1eb411-bfd30439c918c783-00
In middleware of application B, an activity is started and a message is logged. I can also validate that the ParentId of the activity is equal to 00-3abe9f15e940badc5f1521e6eb1eb411-bfd30439c918c783-00. The ParentSpanId is equal to bfd30439c918c783
using var requestActivity = new Activity(context.FunctionDefinition.Name);
requestActivity.SetParentId(traceParent);
requestActivity.Start();
_logger.LogInformation("Invoking '{Name}'", context.FunctionDefinition.Name);
In application insights I see OperationId being equal to the WC3 trace-id 3abe9f15e940badc5f1521e6eb1eb411 as expected. However, the operation_ParentId is a span I've not seen before. It is neither the requestActivity.SpanId nor the requestActivity.ParentSpanId.
What is happening that I do not understand? Does Application Insights not use the active Activity when logging?
my app configuration
var host = new HostBuilder()
.ConfigureFunctionsWorkerDefaults(worker =>
{
worker.UseMiddleware<TracingMiddleware>();
})
.ConfigureServices(collection =>
{
})
.ConfigureLogging(x=>x.AddApplicationInsights())
.Build();
host.Run();
My middleware function
public async Task Invoke(FunctionContext context, FunctionExecutionDelegate next)
{
using var requestActivity = new Activity(context.FunctionDefinition.Name);
SetParentId(context, requestActivity);
requestActivity.Start();
_logger.LogInformation("Invoking '{Name}'", context.FunctionDefinition.Name);
var t = Activity.Current;
System.Console.WriteLine();
System.Console.WriteLine($"Activity.TraceId: {t.TraceId}");
System.Console.WriteLine($"Activity.ParentId: {t.ParentId}");
System.Console.WriteLine($"Activity.SpanId: {t.SpanId}");
await next(context);
var statusCode = (context.Items != null)
? context.GetHttpResponseData()?.StatusCode
: System.Net.HttpStatusCode.OK;
_logger.LogInformation(
"Executed '{Name}', Result {Result}, Duration = {Duration}ms",
context.FunctionDefinition.Name,
statusCode,
(DateTime.UtcNow - requestActivity.StartTimeUtc).TotalMilliseconds);
requestActivity.Stop();
}

Answer 1

As per the MS-Doc the Operation ID is equal to TraceId. And the Operation_parent Id has the combination of both Trace-ID with Parent-ID. The Format has .
The operation_ParentId field is in the format
<trace-id>.<parent-id>, where both trace-id and parent-id are
taken from the trace header that was passed in the request.
I have noticed that It was not actually same. I have tired with many possible ways. I end up with The operation-ID is not equal to the Trace-ID and the Operation-parent-ID is not equal to < Trace-ID>.< Parent-ID>.
In my middle ware i have added the current context like below
ILogger logger = context.GetLogger<MyCustomMiddleware>();
//logger.LogInformation("From function: {message}", message);
using var requestActivity = new Activity(context.FunctionDefinition.Name);
//t.SetParentId(context, requestActivity);
requestActivity.Start();
logger.LogInformation("Invoking '{Name}'", context.FunctionDefinition.Name);
//requestActivity.SetParentId(Convert.ToString(requestActivity.RootId));
requestActivity.SetParentId(requestActivity.TraceId,requestActivity.SpanId,ActivityTraceFlags.None);
var t = Activity.Current;
//Activity.SetParentId(context, requestActivity,);
//t.SetParentId(context, requestActivity)
logger.LogInformation($"Activity.TraceId: {t.TraceId}");
logger.LogInformation($"Activity.ParentId: {t.ParentId}");
logger.LogInformation($"Activity.SpanId: {t.SpanId}");
logger.LogInformation($"Activity.Id: {t.Id}");
logger.LogInformation($"Activity.ParentSpanId: {t.ParentSpanId}");
logger.LogInformation($"Activity.RootId: {t.RootId}");
logger.LogInformation($"Activity.Parent: {t.Parent}");
Result I got.
Refer here for one of my workarounds with more details.