ServiceLevelIndicators 10.0.0-preview.6

ServiceLevelIndicators

A .NET library for emitting Service Level Indicator (SLI) latency metrics in milliseconds via the standard System.Diagnostics.Metrics API. Use it to measure operation duration across any .NET application and attach dimensions such as operation name, customer, location, and outcome so the data is useful for SLO dashboards and alerts.

For ASP.NET Core applications, see ServiceLevelIndicators.Asp.

When To Use This Package

Choose ServiceLevelIndicators when you want to measure operations directly in application code, especially in console apps, worker services, background jobs, libraries, or shared business logic that should stay independent from ASP.NET Core.

If you want automatic measurement of ASP.NET Core endpoints, use ServiceLevelIndicators.Asp instead.

Installation

dotnet add package ServiceLevelIndicators

Quick Start

1. Register with OpenTelemetry

builder.Services.AddOpenTelemetry()
    .WithMetrics(metrics =>
    {
        metrics.AddServiceLevelIndicatorInstrumentation();
        metrics.AddOtlpExporter();
    });

If you supply a custom Meter in ServiceLevelIndicatorOptions, register that same meter with OpenTelemetry:

var sliMeter = new Meter("MyCompany.ServiceLevelIndicator");

builder.Services.AddOpenTelemetry()
    .WithMetrics(metrics =>
    {
        metrics.AddServiceLevelIndicatorInstrumentation(sliMeter);
        metrics.AddOtlpExporter();
    });

builder.Services.Configure<ServiceLevelIndicatorOptions>(options =>
{
    options.Meter = sliMeter;
    options.LocationId = ServiceLevelIndicator.CreateLocationId("public", "westus3");
    options.CustomerResourceId = "my-customer";
});

builder.Services.AddSingleton<ServiceLevelIndicator>();

2. Configure options

builder.Services.Configure<ServiceLevelIndicatorOptions>(options =>
{
    options.LocationId = ServiceLevelIndicator.CreateLocationId("public", "westus3");
    options.CustomerResourceId = "my-customer";
});

builder.Services.AddSingleton<ServiceLevelIndicator>();

3. Measure operations

Wrap any block of code in a using StartMeasuring scope:

async Task DoWork(ServiceLevelIndicator sli)
{
    using var op = sli.StartMeasuring("ProcessOrder");
    // Do work...
    op.SetActivityStatusCode(ActivityStatusCode.Ok);
}

You can also pass custom attributes:

var attribute = new KeyValuePair<string, object?>("Event", "OrderCreated");
using var op = sli.StartMeasuring("ProcessOrder", attribute);

Emitted Metrics

A meter named ServiceLevelIndicator with instrument operation.duration (milliseconds) is emitted with the following attributes:

Cardinality Guidance

Use stable, bounded values for CustomerResourceId and custom attributes. Good dimensions include tenant, subscription, environment, region, or product tier. Avoid highly variable values such as request IDs, email addresses, timestamps, or arbitrary user input unless high-cardinality metrics are intentional and supported by your backend.

Key APIs

Further Reading

• Full documentation and samples
• Package selection and usage reference
• OpenTelemetry .NET