Instrument your .NET application with OpenTelemetry

This walkthrough shows how to add observability to your .NET application using the OpenTelemetry .NET libraries and tools.

Feature	Supported
Automatic Instrumentation	Yes
Automatic OneAgent Ingestion	Yes

Prerequisites

Dynatrace version 1.254+
For tracing, W3C Trace Context is enabled
1. From the Dynatrace menu, go to Settings > Preferences > OneAgent features.
2. Turn on Send W3C Trace Context HTTP headers.

Choose how to ingest data into Dynatrace

Auto-ingest for traces only

OneAgent currently only ingests traces automatically. If you are recording metrics or logs, choose the OTLP export route.

Choose how you want to instrument your application

For .NET, OpenTelemetry supports automatic and manual instrumentation (or a combination of both).

Which instrumentation should I choose?

It's a good idea to start with automatic instrumentation and add manual instrumentation if the automatic approach doesn't work or doesn't provide enough information.

Automatically instrument your application optional

.NET automatic instrumentation can be configured either during development or later after deployment.

Whether you configure automatic instrumentation during development or after deployment, you also need to configure the export parameters (for example, endpoint and protocol), unless you opt for OneAgent ingestion or configure them manually via manual instrumentation.

Manually instrument your application optional

Setup

Add the current version ([VERSION]) of the following packages.

1<PackageReference Include="Microsoft.Extensions.Logging" Version="[VERSION]" />
2<PackageReference Include="OpenTelemetry.Extensions.Hosting" Version="[VERSION]" />
3<PackageReference Include="OpenTelemetry" Version="[VERSION]" />
4<PackageReference Include="OpenTelemetry.Api" Version="[VERSION]" />
5<PackageReference Include="OpenTelemetry.Exporter.OpenTelemetryProtocol" Version="[VERSION]" />

Add the following using statements to the startup class, which bootstraps your application.

1using OpenTelemetry;
2using OpenTelemetry.Trace;
3using OpenTelemetry.Exporter;
4using OpenTelemetry.Metrics;
5using OpenTelemetry.Logs;
6using OpenTelemetry.Resources;
7using OpenTelemetry.Context.Propagation;
8using System.Diagnostics;
9using System.Diagnostics.Metrics;
10using Microsoft.Extensions.Logging;

Add these fields to your startup class, with the first two indicating your Dynatrace URL and access token.

1private static string DT_API_URL = ""; // TODO: Provide your SaaS/Managed URL here
2private static string DT_API_TOKEN = ""; // TODO: Provide the OpenTelemetry-scoped access token here
3
4private const string activitySource = "Dynatrace.DotNetApp.Sample"; // TODO: Provide a descriptive name for your application here
5public static readonly ActivitySource MyActivitySource = new ActivitySource(activitySource);
6private static ILoggerFactory loggerFactoryOT;

Value injection

Instead of hardcoding the URL and token, you might also consider reading them from storage specific to your application framework (for example, environment variables or framework secrets).

Add the initOpenTelemetry method to your startup class and invoke it as early as possible during your application startup. This initializes OpenTelemetry for the Dynatrace backend and creates default tracer and meter providers.

1private static void initOpenTelemetry(IServiceCollection services)
2{
3    List<KeyValuePair<string, object>> dt_metadata = new List<KeyValuePair<string, object>>();
4    foreach (string name in new string[] {"dt_metadata_e617c525669e072eebe3d0f08212e8f2.properties", "/var/lib/dynatrace/enrichment/dt_metadata.properties", "/var/lib/dynatrace/enrichment/dt_host_metadata.properties"}) {
5        try {
6            foreach (string line in System.IO.File.ReadAllLines(name.StartsWith("/var") ? name : System.IO.File.ReadAllText(name))) {
7                var keyvalue = line.Split("=");
8                dt_metadata.Add( new KeyValuePair<string, object>(keyvalue[0], keyvalue[1]));
9            }
10        }
11        catch { }
12    }
13
14    Action<ResourceBuilder> configureResource = r => r
15        .AddService(serviceName: "dotnet-quickstart") //TODO Replace with the name of your application
16        .AddAttributes(dt_metadata);
17
18    services.AddOpenTelemetry()
19        .ConfigureResource(configureResource)
20        .WithTracing(builder => {
21            builder
22                .SetSampler(new AlwaysOnSampler())
23                .AddSource(MyActivitySource.Name)
24                .AddOtlpExporter(options =>
25                {
26                    options.Endpoint = new Uri(Environment.GetEnvironmentVariable("DT_API_URL")+ "/v1/traces");
27                    options.Protocol = OpenTelemetry.Exporter.OtlpExportProtocol.HttpProtobuf;
28                    options.Headers = $"Authorization=Api-Token {Environment.GetEnvironmentVariable("DT_API_TOKEN")}";
29                });
30        })
31        .WithMetrics(builder => {
32            builder
33                .AddMeter("my-meter")
34                .AddOtlpExporter((OtlpExporterOptions exporterOptions, MetricReaderOptions readerOptions) =>
35                {
36                    exporterOptions.Endpoint = new Uri(Environment.GetEnvironmentVariable("DT_API_URL")+ "/v1/metrics");
37                    exporterOptions.Headers = $"Authorization=Api-Token {Environment.GetEnvironmentVariable("DT_API_TOKEN")}";
38                    exporterOptions.Protocol = OpenTelemetry.Exporter.OtlpExportProtocol.HttpProtobuf;
39                    readerOptions.TemporalityPreference = MetricReaderTemporalityPreference.Delta;
40                });
41            });
42
43    var resourceBuilder = ResourceBuilder.CreateDefault();
44    configureResource!(resourceBuilder);
45
46    loggerFactoryOT = LoggerFactory.Create(builder => {
47        builder
48            .AddOpenTelemetry(options => {
49                options.SetResourceBuilder(resourceBuilder).AddOtlpExporter(options => {
50                    options.Endpoint = new Uri(Environment.GetEnvironmentVariable("DT_API_URL")+ "/v1/logs");
51                    options.Headers = $"Authorization=Api-Token {Environment.GetEnvironmentVariable("DT_API_TOKEN")}";
52                    options.ExportProcessorType = OpenTelemetry.ExportProcessorType.Batch;
53                    options.Protocol = OtlpExportProtocol.HttpProtobuf;
54                });
55            })
56            .AddConsole();
57    });
58    Sdk.CreateTracerProviderBuilder()
59        .SetSampler(new AlwaysOnSampler())
60        .AddSource(MyActivitySource.Name)
61        .ConfigureResource(configureResource);
62    // add-logging
63}

Add tracing

Using MyActivitySource from the setup step, we can now start new activities (traces):

1using var activity = Startup.MyActivitySource.StartActivity("Call to /myendpoint", ActivityKind.Consumer, parentContext.ActivityContext);
2activity?.SetTag("http.method", "GET");
3activity?.SetTag("net.protocol.version", "1.1");

In the above code, we:

Create a new activity (span) and name it "Call to /myendpoint"
Add two tags (attributes), following the semantic naming convention, specific to the action of this span: information on the HTTP method and version

The activity will be automatically set as the current and active span until the execution flow leaves the current method scope. Subsequent activities will automatically become child spans.

Collect metrics

To instantiate new metric instruments, we first need a meter object.

1private static readonly Meter meter = new Meter("my-meter", "1.0.0");  //TODO Replace with the name of your meter

With meter, we can now create individual instruments, such as a counter.

1private static readonly Counter<long> counter = meter.CreateCounter<long>("request_counter");

We can now invoke the Add() method of counter to record new values with our counter and save additional attributes (for example, action.type).
```
1counter.Add(1, new("ip", "an ip address here"), new("some other key", "some other value"));
```

Connect logs

With the loggerFactoryOT variable, we initialized under Setup, we can now create individual logger instances, which will pass logged information straight to the configured OpenTelemetry endpoint at Dynatrace.

1var logger = loggerFactoryOT.CreateLogger<Startup>();
2services.AddSingleton<ILoggerFactory>(loggerFactoryOT);
3services.AddSingleton(logger);
4logger.LogInformation(eventId: 123, "Log line");

Ensure context propagation optional

Context propagation is particularly important when network calls (for example, REST) are involved.

If you are using automatic instrumentation and your networking libraries are covered by automatic instrumentation, this will be automatically taken care of by the instrumentation libraries. Otherwise, your code needs to take this into account.

Extracting the context when receiving a request

In the following example, we assume that we have received a network call via System.Web.HttpRequest and we define a CompositeTextMapPropagator instance to fetch the context information from the HTTP headers. We then pass that instance to Extract(), returning the context object, which allows us to continue the previous trace with our spans.

1private CompositeTextMapPropagator propagator = new CompositeTextMapPropagator(new TextMapPropagator[] {
2    new TraceContextPropagator(),
3    new BaggagePropagator(),
4});
5private static readonly Func<HttpRequest, string, IEnumerable<string>> valueGetter = (request, name) => request.Headers[name];
6
7
8var parentContext = propagator.Extract(default, HttpContext.Request, valueGetter);
9
10using var activity = MyActivitySource.StartActivity("my-span", ActivityKind.Consumer, parentContext.ActivityContext);

Injecting the context when sending requests

In the following example, we send a REST request to another service and provide our existing context as part of the HTTP headers of our request.

To do so, we define a TextMapPropagator instance, which adds the respective information. Once we have instantiated our REST object, we pass it, along with the context and the setter instance, to Inject(), which will add the necessary headers to the request.

1private CompositeTextMapPropagator propagator = new CompositeTextMapPropagator(new TextMapPropagator[] {
2    new TraceContextPropagator(),
3    new BaggagePropagator()
4});
5
6private static Action<HttpRequestMessage, string, string> _headerValueSetter => (request, name, value) => {
7    request.Headers.Remove(name);
8    request.Headers.Add(name, value);
9};
10
11propagator.Inject(new PropagationContext(activity!.Context, Baggage.Current), request, _headerValueSetter);

Configure data capture to meet privacy requirements optional

While Dynatrace automatically captures all OpenTelemetry attributes, only attribute values specified in the allowlist are stored and displayed in the Dynatrace web UI. This prevents accidental storage of personal data, so you can meet your privacy requirements and control the amount of monitoring data stored.

To view your custom attributes, you need to allow them in the Dynatrace web UI first. To learn how to configure attribute storage and masking, see Attribute redaction.

Verify data ingestion into Dynatrace

Once you have finished the instrumentation of your application, perform a couple of test actions to create and send demo traces, metrics, and logs and verify that they were correctly ingested into Dynatrace.

To do that for traces, in the Dynatrace menu, go to Distributed traces and select the Ingested traces tab. If you use OneAgent, select PurePaths instead.

Metrics and logs can be found under their respective entries at Observe and explore.