使用示例

./jaeger-all-in-one --collector.otlp.enabled

./prometheus --enable-feature=exemplar-storage --web.enable-otlp-receiver

using System;
using System.Diagnostics;
using System.Threading;
using OpenTelemetry;
using OpenTelemetry.Metrics;
using OpenTelemetry.Resources;
using OpenTelemetry.Trace;

// Create a resource with service information
var resource = ResourceBuilder.CreateDefault()
    .AddService(serviceName: "exemplars-demo", serviceVersion: "1.0.0");

// Create a tracer provider
using var tracerProvider = Sdk.CreateTracerProviderBuilder()
    .SetResourceBuilder(resource)
    .AddSource("MyCompany.MyProduct.MyLibrary")
    .AddOtlpExporter(options => options.Endpoint = new Uri("https://:4317"))
    .Build();

// Create a meter provider with exemplar support
using var meterProvider = Sdk.CreateMeterProviderBuilder()
    .SetResourceBuilder(resource)
    .AddMeter("MyCompany.MyProduct.MyLibrary")
    .SetExemplarFilter(ExemplarFilterType.TraceBased)  // Enable trace-based exemplars
    .AddOtlpExporter(options => options.Endpoint = new Uri("https://:9090/api/v1/otlp"))
    .Build();

// Create activity source and meter
var activitySource = new ActivitySource("MyCompany.MyProduct.MyLibrary");
var meter = new Meter("MyCompany.MyProduct.MyLibrary");

// Create a histogram instrument for recording measurements
var histogram = meter.CreateHistogram<double>("MyHistogram", unit: "ms", description: "Example histogram");

var random = new Random();

// Generate sample data
for (int i = 0; i < 100; i++)
{
    // Start an activity (span)
    using (var activity = activitySource.StartActivity("ProcessData"))
    {
        // Add some attributes to the activity
        activity?.SetTag("iteration", i);

        // Simulate work
        var value = random.NextDouble() * 100;
        Thread.Sleep((int)value);

        // Record a measurement - this will include exemplar with trace context
        // because we set ExemplarFilterType.TraceBased and have an active activity
        histogram.Record(value);
    }

    // Sleep between iterations
    Thread.Sleep(100);
}

Console.WriteLine("Application running and sending data. Press any key to exit.");
Console.ReadKey();