Docs » Supported integrations in Splunk Observability Cloud » Instrument back-end applications to send spans to Splunk APM » Instrument .NET applications for Splunk Observability Cloud (OpenTelemetry) » SignalFx Instrumentation for .NET (Deprecated) » .NET application for Splunk Observability Cloud

Caution

The SignalFx Instrumentation for .NET is deprecated as of February 21, 2024 and will reach End of Support on February 21 2025. Until then, only critical security fixes and bug fixes will be provided. After the date, the library will be archived and no longer maintained.

New customers instrumenting the .NET ecosystem should use the Splunk Distribution of OpenTelemetry .NET. Existing customers should consider migrating to Splunk Distribution of OpenTelemetry .NET which offers similar capabilities. To learn how to migrate, see Migrate from the SignalFx .NET Instrumentation.

.NET application for Splunk Observability Cloud 🔗

The SignalFx Instrumentation for .NET automatically instruments .NET applications, Windows services running .NET applications, ASP.NET applications deployed on IIS, and Azure App Service applications.

To get started, follow the instructions to install the SignalFx Instrumentation for .NET manually.

Install the SignalFx Instrumentation for .NET manually 🔗

If you don’t use the guided setup, follow these instructions to manually install the SignalFx Instrumentation for .NET:

Instrument your .NET application 🔗

Follow these steps to automatically instrument your application:

  1. Check that you meet the requirements. See .NET instrumentation compatibility and requirements.

  2. Download the latest release of the SignalFx Instrumentation for .NET for your operating system from the Releases page on GitHub .

  3. Install the package for your operating system:

    msiexec /i signalfx-dotnet-tracing-<version-here>-x64.msi /quiet

  4. Set the following environment variables:

    # Set the following variables in the process scope
$Env:COR_ENABLE_PROFILING = "1"
$Env:COR_PROFILER = "{B4C89B0F-9908-4F73-9F59-0D77C5A06874}"
$Env:CORECLR_ENABLE_PROFILING = "1"
$Env:CORECLR_PROFILER = "{B4C89B0F-9908-4F73-9F59-0D77C5A06874}"
$Env:SIGNALFX_SERVICE_NAME = "<my-service-name>"
$Env:SIGNALFX_ENV = "<your-environment>"

    • Avoid setting the environment variables in the system or user scopes in Windows unless you require permanent autoinstrumentation. See Configure the SignalFx Instrumentation for .NET for more information on how to include or exclude processes for autoinstrumentation.

  5. (Optional) To activate automatic metric collection, see Activate metrics collection.

  6. Run your application.

If no data appears in APM, see Troubleshoot .NET instrumentation for Splunk Observability Cloud.

If you need to add custom attributes to spans or want to manually generate spans, instrument your .NET application or service manually. See Manually instrument .NET applications for Splunk Observability Cloud.

Activate AlwaysOn Profiling 🔗

To activate AlwaysOn Profiling, set the SIGNALFX_PROFILER_ENABLED environment variable to true.

To activate memory profiling, set the SIGNALFX_PROFILER_MEMORY_ENABLED environment variable to true after activating AlwaysOn Profiling.

See Get data into Splunk APM AlwaysOn Profiling for more information. For more settings, see .NET settings for AlwaysOn Profiling.

Activate metrics collection 🔗

To activate automatic metric collection, set the SIGNALFX_TRACE_METRICS_ENABLED environment variable to true.

To activate runtime metrics, set the SIGNALFX_RUNTIME_METRICS_ENABLED environment variable to true.

See Metrics collected by the SignalFx Instrumentation for .NET for more information about the metrics collected by the instrumentation. For more metric settings, see Metrics settings.

Note

Runtime metrics are always collected if AlwaysOn Profiling is activated.

Instrument your Windows service running a .NET application 🔗

To instrument a Windows service, install the instrumentation and set the following environment variables:

$svcName = "MySrv"    # Name of the Windows service you want to instrument
[string[]] $vars = @(
   "COR_ENABLE_PROFILING=1",                                  # Activate .NET Framework Profiler
   "COR_PROFILER={B4C89B0F-9908-4F73-9F59-0D77C5A06874}",     # Select .NET Framework Profiler
   "CORECLR_ENABLE_PROFILING=1",                              # Activate .NET (Core) Profiler
   "CORECLR_PROFILER={B4C89B0F-9908-4F73-9F59-0D77C5A06874}", # Select .NET (Core) Profiler
   "SIGNALFX_SERVICE_NAME=<my-service-name>",                 # Set service name
   "SIGNALFX_ENV=<environment-name>"                          # Set environment name
)
Set-ItemProperty HKLM:SYSTEM\CurrentControlSet\Services\$svcName -Name Environment -Value $vars
# Every time you start the service, it will be auto-instrumented.

For more information on the default service name, see Changing the default service name.

Instrument your ASP.NET application deployed on IIS 🔗

To instrument an ASP.NET application running on IIS, install the instrumentation and edit the web.config file to add the following settings. See Configuration methods for more information.

Add the following settings inside the <appSettings> block of your web.config file:

<add key="SIGNALFX_SERVICE_NAME" value="service-name" />
<add key="SIGNALFX_ENV" value="environment-name" />

After applying the changes to the web.config file, restart IIS by running the following command:

Start-Process "iisreset.exe" -NoNewWindow -Wait

In some cases, you might have to restart the machine.

Note

By default, the installer activates IIS instrumentation for .NET Framework by setting the Environment registry key for W3SVC and WAS services located in the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services folder.

Instrument your application in Azure App Service 🔗

To instrument an application or service in Azure App Service, follow these steps:

  1. Find and install the SignalFx .NET Tracing extension in your application. See Adding Extensions to Web Apps in Azure App Service in the Azure documentation for more information.

  2. Add the following application settings. See Configure Apps in the Azure documentation for more information.

    Name

    Value

    SIGNALFX_ACCESS_TOKEN

    Your Splunk access token. To obtain an access token, see Retrieve and manage user API access tokens using Splunk Observability Cloud.

    SIGNALFX_REALM

    realm is the Splunk Observability Cloud realm, for example, us0. To find your Splunk realm, see Note about realms.

    SIGNALFX_SERVICE_NAME

    The name of your service or application.

    SIGNALFX_ENV

    The name of your environment where you’re instrumenting the application.

  3. Restart the application.

Note

To reduce latency and benefit from OTel Collector features, set the endpoint URL to a Collector instance running in Azure VM over an Azure VNet.

Instrument your background task in Azure App Service 🔗

When instrumenting an Azure WebJob in App Service, add the following settings. Replace <extension-version> in system paths with the version of the .NET instrumentation, for example, v0.2.0:

Name

Value

SIGNALFX_ACCESS_TOKEN

Your Splunk access token. To obtain an access token, see Retrieve and manage user API access tokens using Splunk Observability Cloud.

SIGNALFX_REALM

realm is the Splunk Observability Cloud realm, for example, us0. To find the realm name of your account, open the navigation menu in Splunk Observability Cloud, select Settings, and select your username. The realm name appears in the Organizations section.

SIGNALFX_SERVICE_NAME

The name of your service or application.

SIGNALFX_ENV

The name of your environment where you’re instrumenting the application.

COR_ENABLE_PROFILING

1

COR_PROFILER

{B4C89B0F-9908-4F73-9F59-0D77C5A06874}

COR_PROFILER_PATH

C:\home\signalfx\tracing\<extension-version>\win-x64\SignalFx.Tracing.ClrProfiler.Native.dll

COR_PROFILER_PATH_32

C:\home\signalfx\tracing\<extension-version>\win-x86\SignalFx.Tracing.ClrProfiler.Native.dll

COR_PROFILER_PATH_64

C:\home\signalfx\tracing\<extension-version>\win-x64\SignalFx.Tracing.ClrProfiler.Native.dll

CORECLR_ENABLE_PROFILING

1

CORECLR_PROFILER

{B4C89B0F-9908-4F73-9F59-0D77C5A06874}

CORECLR_PROFILER_PATH_32

C:\home\signalfx\tracing\<extension-version>\win-x86\SignalFx.Tracing.ClrProfiler.Native.dll

CORECLR_PROFILER_PATH_64

C:\home\signalfx\tracing\<extension-version>\win-x64\SignalFx.Tracing.ClrProfiler.Native.dll

SIGNALFX_DOTNET_TRACER_HOME

C:\home\signalfx\tracing\<extension-version>

SIGNALFX_PROFILER_EXCLUDE_PROCESSES

SnapshotUploader.exe;workerforwarder.exe

SIGNALFX_TRACE_LOG_PATH

C:\home\LogFiles\signalfx\tracing\<extension-version>\dotnet-profiler.log

SIGNALFX_AZURE_APP_SERVICES

0

Caution

Set SIGNALFX_AZURE_APP_SERVICES to 0 when instrumenting WebJobs. Keep a separate App Service for the WebJob, so that you can use separate settings for your application and for the background service.

Activate AlwaysOn Profiling 🔗

AlwaysOn Profiling requires .NET 6.0 or higher.

Limited support is available for the following legacy versions of .NET:

  • CPU profiling: .NET Core 3.1 and .NET 5.x

  • Memory profiling: .NET Core 5.x

To activate AlwaysOn Profiling, do the following:

  • Activate the profiler by setting the SIGNALFX_PROFILER_ENABLED environment variable to true for your .NET process.

  • Activate memory profiling by setting the SIGNALFX_PROFILER_MEMORY_ENABLED environment variable to true.

For more configuration options, including setting a separate endpoint for profiling data, see .NET settings for AlwaysOn Profiling.

Deploy the .NET instrumentation in Kubernetes 🔗

To deploy the .NET instrumentation in Kubernetes, configure the Kubernetes Downward API to expose environment variables to Kubernetes resources.

The following example shows how to update a deployment to expose environment variables by adding the agent configuration under the .spec.template.spec.containers.env section:

apiVersion: apps/v1
kind: Deployment
spec:
  selector:
    matchLabels:
      app: your-application
  template:
    spec:
      containers:
        - name: myapp
          env:
            - name: SPLUNK_OTEL_AGENT
              valueFrom:
                fieldRef:
                  fieldPath: status.hostIP
            - name: SIGNALFX_ENDPOINT_URL
              value: "http://$(SPLUNK_OTEL_AGENT):9411/api/v2/spans"
            - name: SIGNALFX_SERVICE_NAME
              value: '<name-of-your-service>'
            - name: SIGNALFX_ENV
              value: '<name-of-your-environment>'
            - name: CORECLR_ENABLE_PROFILING
              value: "1"
            - name: CORECLR_PROFILER
              value: '{B4C89B0F-9908-4F73-9F59-0D77C5A06874}'
            - name: CORECLR_PROFILER_PATH
              value: '/opt/signalfx/SignalFx.Tracing.ClrProfiler.Native.so'
            - name: SIGNALFX_DOTNET_TRACER_HOME
              value: '/opt/signalfx'

Send data directly to Splunk Observability Cloud 🔗

By default, the instrumentation sends all telemetry to the local instance of the Splunk Distribution of OpenTelemetry Collector.

To bypass the OTel Collector and send data directly to Splunk Observability Cloud, set the following environment variables:

$env:SIGNALFX_ACCESS_TOKEN=<access_token>
$env:SIGNALFX_REALM=<realm>

To obtain an access token, see Retrieve and manage user API access tokens using Splunk Observability Cloud.

In the ingest endpoint URL, realm is the Splunk Observability Cloud realm, for example, us0. To find the realm name of your account, follow these steps:

  1. Open the navigation menu in Splunk Observability Cloud.

  2. Select Settings.

  3. Select your username.

The realm name appears in the Organizations section.

For more information on the ingest API endpoints, see Send APM traces .

Caution

This procedure applies to spans and traces. To send AlwaysOn Profiling data, you must use the OTel Collector.

Specify the source host 🔗

To override the host used by the agent, use the environment variable OTEL_RESOURCE_ATTRIBUTES to set your host’s name to the desired source:

export OTEL_RESOURCE_ATTRIBUTES=host.name=<host_name>