Exporters

Send telemetry to the OpenTelemetry Collector to make sure it’s exported correctly. Using the Collector in production environments is a best practice. To visualize your telemetry, export it to a backend such as Jaeger, Zipkin, Prometheus, or a vendor-specific backend.

Available exporters

The registry contains a list of exporters for .NET.

Among exporters, OpenTelemetry Protocol (OTLP) exporters are designed with the OpenTelemetry data model in mind, emitting OTel data without any loss of information. Furthermore, many tools that operate on telemetry data support OTLP (such as Prometheus, Jaeger, and most vendors), providing you with a high degree of flexibility when you need it. To learn more about OTLP, see OTLP Specification.

This page covers the main OpenTelemetry .NET exporters and how to set them up.

OTLP

Collector Setup

To try out and verify your OTLP exporters, you can run the collector in a docker container that writes telemetry directly to the console.

In an empty directory, create a file called collector-config.yaml with the following content:

receivers:
  otlp:
    protocols:
      grpc:
        endpoint: 0.0.0.0:4317
      http:
        endpoint: 0.0.0.0:4318
exporters:
  debug:
    verbosity: detailed
service:
  pipelines:
    traces:
      receivers: [otlp]
      exporters: [debug]
    metrics:
      receivers: [otlp]
      exporters: [debug]
    logs:
      receivers: [otlp]
      exporters: [debug]

Now run the collector in a docker container:

docker run -p 4317:4317 -p 4318:4318 --rm -v $(pwd)/collector-config.yaml:/etc/otelcol/config.yaml otel/opentelemetry-collector

This collector is now able to accept telemetry via OTLP. Later you may want to configure the collector to send your telemetry to your observability backend.

Dependencies

If you want to send telemetry data to an OTLP endpoint (like the OpenTelemetry Collector, Jaeger or Prometheus), you can choose between two different protocols to transport your data:

  • HTTP/protobuf
  • gRPC

Start by installing the OpenTelemetry.Exporter.OpenTelemetryProtocol package as a dependency for your project:

dotnet add package OpenTelemetry.Exporter.OpenTelemetryProtocol

If you’re using ASP.NET Core install the OpenTelemetry.Extensions.Hosting package as well:

dotnet add package OpenTelemetry.Extensions.Hosting

Usage

ASP.NET Core

Configure the exporters in your ASP.NET Core services:

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddOpenTelemetry()
    .WithTracing(tracing => tracing
        // The rest of your setup code goes here
        .AddOtlpExporter())
    .WithMetrics(metrics => metrics
        // The rest of your setup code goes here
        .AddOtlpExporter());

builder.Logging.AddOpenTelemetry(logging => {
    // The rest of your setup code goes here
    logging.AddOtlpExporter();
});

This will, by default, send telemetry using gRPC to http://localhost:4317, to customize this to use HTTP and the protobuf format, you can add options like this:

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddOpenTelemetry()
    .WithTracing(tracing => tracing
        // The rest of your setup code goes here
        .AddOtlpExporter(options =>
        {
            options.Endpoint = new Uri("your-endpoint-here/v1/traces");
            options.Protocol = OtlpExportProtocol.HttpProtobuf;
        }))
    .WithMetrics(metrics => metrics
        // The rest of your setup code goes here
        .AddOtlpExporter(options =>
        {
            options.Endpoint = new Uri("your-endpoint-here/v1/metrics");
            options.Protocol = OtlpExportProtocol.HttpProtobuf;
        }));

builder.Logging.AddOpenTelemetry(logging => {
    // The rest of your setup code goes here
    logging.AddOtlpExporter(options =>
    {
        options.Endpoint = new Uri("your-endpoint-here/v1/logs");
        options.Protocol = OtlpExportProtocol.HttpProtobuf;
    });
});

Non-ASP.NET Core

Configure the exporter when creating a TracerProvider, MeterProvider or LoggerFactory:

var tracerProvider = Sdk.CreateTracerProviderBuilder()
    // Other setup code, like setting a resource goes here too
    .AddOtlpExporter(options =>
    {
        options.Endpoint = new Uri("your-endpoint-here/v1/traces");
        options.Protocol = OtlpExportProtocol.HttpProtobuf;
    })
    .Build();

var meterProvider = Sdk.CreateMeterProviderBuilder()
    // Other setup code, like setting a resource goes here too
    .AddOtlpExporter(options =>
    {
        options.Endpoint = new Uri("your-endpoint-here/v1/metrics");
        options.Protocol = OtlpExportProtocol.HttpProtobuf;
    })
    .Build();

var loggerFactory = LoggerFactory.Create(builder =>
{
    builder.AddOpenTelemetry(logging =>
    {
        logging.AddOtlpExporter(options =>
        {
            options.Endpoint = new Uri("your-endpoint-here/v1/logs");
            options.Protocol = OtlpExportProtocol.HttpProtobuf;
        })
    });
});

Use environment variables to set values like headers and an endpoint URL for production.

Console

Dependencies

The console exporter is useful for development and debugging tasks, and is the simplest to set up. Start by installing the OpenTelemetry.Exporter.Console package as a dependency for your project:

dotnet add package OpenTelemetry.Exporter.Console

If you’re using ASP.NET Core install the OpenTelemetry.Extensions.Hosting package as well:

dotnet add package OpenTelemetry.Extensions.Hosting

Usage

ASP.NET Core

Configure the exporter in your ASP.NET Core services:

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddOpenTelemetry()
    .WithTracing(tracing => tracing
        // The rest of your setup code goes here
        .AddConsoleExporter()
    )
    .WithMetrics(metrics => metrics
        // The rest of your setup code goes here
        .AddConsoleExporter()
    );

builder.Logging.AddOpenTelemetry(logging => {
    // The rest of your setup code goes here
    logging.AddConsoleExporter();
});

Non-ASP.NET Core

Configure the exporter when creating a TracerProvider, MeterProvider or LoggerFactory:

var tracerProvider = Sdk.CreateTracerProviderBuilder()
    // The rest of your setup code goes here
    .AddConsoleExporter()
    .Build();

var meterProvider = Sdk.CreateMeterProviderBuilder()
    // The rest of your setup code goes here
    .AddConsoleExporter()
    .Build();

var loggerFactory = LoggerFactory.Create(builder =>
{
    builder.AddOpenTelemetry(logging =>
    {
        logging.AddConsoleExporter();
    });
});

Jaeger

Backend Setup

Jaeger natively supports OTLP to receive trace data. You can run Jaeger in a docker container with the UI accessible on port 16686 and OTLP enabled on ports 4317 and 4318:

docker run --rm \
  -e COLLECTOR_ZIPKIN_HOST_PORT=:9411 \
  -p 16686:16686 \
  -p 4317:4317 \
  -p 4318:4318 \
  -p 9411:9411 \
  jaegertracing/all-in-one:latest

Usage

Now following the instruction to setup the OTLP exporters.

Prometheus

To send your metric data to Prometheus, you can either enable Prometheus’ OTLP Receiver and use the OTLP exporter or you can use the Prometheus exporter, a MetricReader that starts an HTTP server that collects metrics and serialize to Prometheus text format on request.

Backend Setup

You can run Prometheus in a docker container, accessible on port 9090 by following these instructions:

Create a file called prometheus.yml with the following content:

scrape_configs:
  - job_name: dice-service
    scrape_interval: 5s
    static_configs:
      - targets: [host.docker.internal:9464]

Run Prometheus in a docker container with the UI accessible on port 9090:

docker run --rm -v ${PWD}/prometheus.yml:/prometheus/prometheus.yml -p 9090:9090 prom/prometheus --web.enable-otlp-receiver

The following sections provide detailed, .NET-specific instructions for configuring the Prometheus exporter.

There are two approaches for exporting metrics to Prometheus:

  1. Using OTLP Exporter (Push): Push metrics to Prometheus using the OTLP protocol. This requires Prometheus’ OTLP Receiver to be enabled. This is the recommended approach for production environments as it supports exemplars and is stable.

  2. Using Prometheus Exporter (Pull/Scrape): Expose a scraping endpoint in your application that Prometheus can scrape. This is the traditional Prometheus approach.

Using OTLP Exporter (Push)

This approach uses the OTLP exporter to push metrics directly to Prometheus' OTLP receiver endpoint. This is recommended for production environments because it supports exemplars and uses the stable OTLP protocol.

Dependencies

Install the OpenTelemetry.Exporter.OpenTelemetryProtocol package as a dependency for your project:

dotnet add package OpenTelemetry.Exporter.OpenTelemetryProtocol

If you’re using ASP.NET Core install the OpenTelemetry.Extensions.Hosting package as well:

dotnet add package OpenTelemetry.Extensions.Hosting
Usage
ASP.NET Core

Configure the OTLP exporter to send metrics to Prometheus OTLP receiver:

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddOpenTelemetry()
    .WithMetrics(metrics => metrics
        // The rest of your setup code goes here
        .AddOtlpExporter(options =>
        {
            options.Endpoint = new Uri("http://localhost:9090/api/v1/otlp/v1/metrics");
            options.Protocol = OtlpExportProtocol.HttpProtobuf;
        }));
Non-ASP.NET Core

Configure the exporter when creating a MeterProvider:

var meterProvider = Sdk.CreateMeterProviderBuilder()
    // Other setup code, like setting a resource goes here too
    .AddOtlpExporter(options =>
    {
        options.Endpoint = new Uri("http://localhost:9090/api/v1/otlp/v1/metrics");
        options.Protocol = OtlpExportProtocol.HttpProtobuf;
    })
    .Build();

Using Prometheus Exporter (Pull/Scrape)

This approach exposes a metrics endpoint in your application (e.g., /metrics) that Prometheus scrapes at regular intervals.

Dependencies

Install the exporter package as a dependency for your application:

dotnet add package OpenTelemetry.Exporter.Prometheus.AspNetCore --version 1.15.0-beta.1

If you’re using ASP.NET Core install the OpenTelemetry.Extensions.Hosting package as well:

dotnet add package OpenTelemetry.Extensions.Hosting
Usage
ASP.NET Core

Configure the exporter in your ASP.NET Core services:

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddOpenTelemetry()
    .WithMetrics(metrics => metrics.AddPrometheusExporter());

You’ll then need to register the Prometheus scraping middleware so that Prometheus can scrape your application. Use the UseOpenTelemetryPrometheusScrapingEndpoint extension method on IApplicationBuilder:

var builder = WebApplication.CreateBuilder(args);

// ... Setup

var app = builder.Build();

app.UseOpenTelemetryPrometheusScrapingEndpoint();

await app.RunAsync();

By default, this exposes the metrics endpoint at /metrics. You can customize the endpoint path or use a predicate function for more advanced configuration:

app.UseOpenTelemetryPrometheusScrapingEndpoint(
    context => context.Request.Path == "/internal/metrics"
        && context.Connection.LocalPort == 5067);
Non-ASP.NET Core

For applications not using ASP.NET Core, you can use the HttpListener version which is available in a different package:

dotnet add package OpenTelemetry.Exporter.Prometheus.HttpListener --version 1.15.0-beta.1

Then this is setup directly on the MeterProviderBuilder:

var meterProvider = Sdk.CreateMeterProviderBuilder()
    .AddMeter(MyMeter.Name)
    .AddPrometheusHttpListener(
        options => options.UriPrefixes = new string[] { "http://localhost:9464/" })
    .Build();
Prometheus Configuration (Scrape)

When using the Prometheus exporter (pull/scrape approach), you need to configure Prometheus to scrape your application. Add the following to your prometheus.yml:

scrape_configs:
  - job_name: 'your-app-name'
    scrape_interval: 5s
    static_configs:
      - targets: ['localhost:5000'] # Your application's host:port

For more details on configuring the Prometheus exporter, see OpenTelemetry.Exporter.Prometheus.AspNetCore.

Zipkin

Backend Setup

You can run Zipkin on in a Docker container by executing the following command:

docker run --rm -d -p 9411:9411 --name zipkin openzipkin/zipkin

Dependencies

To send your trace data to Zipkin, install the exporter package as a dependency for your application:

dotnet add package OpenTelemetry.Exporter.Zipkin

If you’re using ASP.NET Core install the OpenTelemetry.Extensions.Hosting package as well:

dotnet add package OpenTelemetry.Extensions.Hosting

Usage

ASP.NET Core

Configure the exporter in your ASP.NET Core services:

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddOpenTelemetry()
    .WithTracing(tracing => tracing
        // The rest of your setup code goes here
        .AddZipkinExporter(options =>
        {
            options.Endpoint = new Uri("your-zipkin-uri-here");
        }));

Non-ASP.NET Core

Configure the exporter when creating a tracer provider:

var tracerProvider = Sdk.CreateTracerProviderBuilder()
    // The rest of your setup code goes here
    .AddZipkinExporter(options =>
    {
        options.Endpoint = new Uri("your-zipkin-uri-here");
    })
    .Build();