How to troubleshoot missing spans in an ASP.NET Core application with OpenTelemetry Collector?
I'm working through a tutorial and I'm performance testing and I'm currently implementing observability in an ASP.NET Core application using OpenTelemetry, and I've run into a important scenario where spans are intermittently missing from the traces collected by the OpenTelemetry Collector... My setup involves .NET 6 and I'm using version 1.2.0 of the OpenTelemetry SDK. I have configured my `Startup.cs` like this: ```csharp public void ConfigureServices(IServiceCollection services) { services.AddOpenTelemetryTracing(builder => { builder .AddAspNetCoreInstrumentation() .AddHttpClientInstrumentation() .AddConsoleExporter() .SetResourceBuilder(ResourceBuilder.CreateDefault().AddService("MyAspNetCoreApp")); }); } ``` Despite this configuration, I've noticed that certain HTTP requests do not generate any spans, especially when they are quick and do not involve any dependencies. For instance, a simple GET request to an endpoint that just returns static JSON: ```csharp [HttpGet] public IActionResult GetData() { return Ok(new { Message = "Hello, World!" }); } ``` When I check the OpenTelemetry Collector logs, I see this warning: ``` 2023-10-01T15:20:00Z WARN otelcol: received batch with no spans ``` I've tried increasing the sampling rate and ensuring that the `AddAspNetCoreInstrumentation()` method is being called. However, the question continues. To debug, I've also added logging to track when spans are started and completed, but they seem to be omitted from the trace altogether if the processing time is under 10ms. Could it be related to the default sampling configuration? I suspect that very fast operations might not be captured, but Iām not sure how to adjust settings to alleviate this scenario. Has anyone experienced similar problems, or can anyone provide insight into how to ensure that these short-lived spans are properly created and sent to the collector? Thanks, I really appreciate it! Has anyone else encountered this?