Metrics and tracing

Surefire emits metrics via System.Diagnostics.Metrics and traces via System.Diagnostics.ActivitySource. Both use the name "Surefire".

Instruments

Instrument	Type	Unit	Description
surefire.runs.claimed	Counter	—	Runs claimed by workers
surefire.runs.completed	Counter	—	Runs completed successfully
surefire.runs.failed	Counter	—	Runs that reached dead letter
surefire.runs.cancelled	Counter	—	Runs cancelled
surefire.runs.duration.ms	Histogram	ms	Run execution duration

Current counters and histograms are emitted without additional metric tags.

Traces

The "Surefire" activity source creates surefire.run.execute spans with these tags:

Tag	Description
surefire.run.id	The run ID
surefire.run.job	The job name
surefire.run.attempt	Attempt number
surefire.run.parent	Parent run ID (if any)

Failed jobs set the span status to Error with the exception message.

Setup

Install the OpenTelemetry packages:

dotnet add package OpenTelemetry.Extensions.Hosting
dotnet add package OpenTelemetry.Exporter.OpenTelemetryProtocol
dotnet add package OpenTelemetry.Exporter.Console           # optional, for local dev

Wire up the meter and activity source in your host builder:

using OpenTelemetry.Metrics;
using OpenTelemetry.Trace;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddOpenTelemetry()
    .WithMetrics(metrics =>
    {
        metrics.AddMeter("Surefire");
        metrics.AddOtlpExporter();
        // metrics.AddConsoleExporter(); // uncomment for local dev
    })
    .WithTracing(tracing =>
    {
        tracing.AddSource("Surefire");
        tracing.AddOtlpExporter();
        // tracing.AddConsoleExporter(); // uncomment for local dev
    });

builder.Services.AddSurefire();

The OTLP exporter sends data to any OpenTelemetry-compatible backend (Jaeger, Grafana, Aspire Dashboard, etc.). By default it connects to http://localhost:4317. Configure via environment variables:

OTEL_EXPORTER_OTLP_ENDPOINT=http://localhost:4317
OTEL_SERVICE_NAME=my-app

.NET Aspire

If you’re using .NET Aspire, metrics and traces are collected automatically — just add the meter and source:

builder.Services.AddOpenTelemetry()
    .WithMetrics(m => m.AddMeter("Surefire"))
    .WithTracing(t => t.AddSource("Surefire"));