First, download and install the .NET SDK on your computer.
Create a new console application and run it:
dotnet new console --output getting-started
cd getting-started
dotnet run
You should see the following output:
Hello World!
Install the OpenTelemetry.Exporter.Console package:
dotnet add package OpenTelemetry.Exporter.Console
Update the Program.cs
file with the code from Program.cs:
Run the application again (using dotnet run
) and you should see the trace
output from the console.
Activity.TraceId: d4a7d499698d62f0e2317a67abc559b6
Activity.SpanId: a091d18fbe45bdf6
Activity.TraceFlags: Recorded
Activity.ActivitySourceName: MyCompany.MyProduct.MyLibrary
Activity.DisplayName: SayHello
Activity.Kind: Internal
Activity.StartTime: 2022-03-30T19:42:33.5178011Z
Activity.Duration: 00:00:00.0097620
StatusCode : Ok
Activity.Tags:
foo: 1
bar: Hello, World!
baz: [1, 2, 3]
Resource associated with Activity:
service.name: unknown_service:getting-started
Congratulations! You are now collecting traces using OpenTelemetry.
What does the above program do?
The program creates an ActivitySource
which represents an OpenTelemetry
Tracer.
private static readonly ActivitySource MyActivitySource = new ActivitySource(
"MyCompany.MyProduct.MyLibrary");
The ActivitySource
instance is used to start an Activity
which represents an
OpenTelemetry
Span
and set several Tags
, which represents
Attributes
on it. It also sets the Status
to be Ok
.
using (var activity = MyActivitySource.StartActivity("SayHello"))
{
activity?.SetTag("foo", 1);
activity?.SetTag("bar", "Hello, World!");
activity?.SetTag("baz", new int[] { 1, 2, 3 });
activity?.SetStatus(ActivityStatusCode.Ok);
}
An OpenTelemetry
TracerProvider
is configured to subscribe to the activities from the source
MyCompany.MyProduct.MyLibrary
, and export it to ConsoleExporter
.
ConsoleExporter
simply displays it on the console.
using var tracerProvider = Sdk.CreateTracerProviderBuilder()
.AddSource("MyCompany.MyProduct.MyLibrary")
.AddConsoleExporter()
.Build();
As shown in the above program, a valid TracerProvider
must be configured and
built to collect traces with OpenTelemetry .NET SDK. TracerProvider
holds all
the configuration for tracing like samplers, processors, etc. and is highly
customizable.
If you tried the above program, you may have already noticed that the terms
ActivitySource
and Activity
were used instead of Tracer
and Span
from
OpenTelemetry specification. This results from the fact that, Traces in
OpenTelemetry .NET is a somewhat unique implementation of the OpenTelemetry
project, as most of the Trace
API
is implemented by the .NET runtime itself.
From a high level, what this means is that you can instrument your application
by simply depending on System.Diagnostics.DiagnosticSource
package, which
provides Activity
and ActivitySource
classes representing the OpenTelemetry
concepts of
Span
and
Tracer
respectively. Read
this
to learn more.
- If you want to customize the Sdk, refer to customizing the SDK.
- If you want to build a custom exporter/processor/sampler, refer to extending the SDK.