If you encounter any issue with OpenTelemetry .NET Automatic Instrumentation, there are steps that can help you understand the issue.
Detailed debug logs can help you troubleshoot instrumentation issues, and can be attached to issues in this project to facilitate investigation.
To get the detailed logs from the OpenTelemetry .NET Automatic Instrumentation, set
the OTEL_LOG_LEVEL
environment variable to debug
before the instrumented process starts.
By default, the library writes the log files under predefined locations.
If needed, change the default location by updating the OTEL_DOTNET_AUTO_LOG_DIRECTORY
environment variable.
After obtaining the logs, remove the OTEL_LOG_LEVEL
environment variable, or set it to less verbose level
to avoid unnecessary overhead.
Host tracing can be used to gather the information needed to investigate the problems related to various issues, like assemblies not being found. Set the following environment variables:
COREHOST_TRACE=1
COREHOST_TRACEFILE=corehost_verbose_tracing.log
Then restart the application to collect the logs.
There is no telemetry generated. There are no logs in OpenTelemetry .NET Automatic Instrumentation internal logs location.
It might occur that the .NET Profiler is unable to attach and therefore no logs would be emitted.
The most common reason is that the instrumented application has no permissions to load the OpenTelemetry .NET Automatic Instrumentation assemblies.
When adding the NuGet packages to your project you get an error message similar to:
Could not install package 'OpenTelemetry.AutoInstrumentation.Runtime.Native 1.9.0'. You are trying to install this package into a project that targets '.NETFramework,Version=v4.7.2', but the package does not contain any assembly references or content files that are compatible with that framework. For more information, contact the package author.
The NuGet packages don't support old-style csproj
projects. Either deploy the
automatic instrumentation to the machine instead of using NuGet packages,
or migrate your project to the SDK style csproj
.
High CPU usage.
Make sure that you have not enabled the automatic instrumentation globally by setting the environment variables at system or user scope.
If the usage of system or user scope is intentional, use the OTEL_DOTNET_AUTO_EXCLUDE_PROCESSES
environment variables to exclude applications from the automatic instrumentation.
You get error messages similar to the one below when running an app,
for example with dotnet run
:
PS C:\Users\Administrator\Desktop\OTelConsole-NET6.0> dotnet run My.Simple.Console
Unhandled exception. System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
---> System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
---> System.TypeInitializationException: The type initializer for 'OpenTelemetry.AutoInstrumentation.Loader.Startup' threw an exception.
---> System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
---> System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.Extensions.Configuration.Abstractions, Version=7.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'. The system cannot find the file specified.
With version v0.6.0-beta.1
and lower, there were issues when instrumenting
the dotnet
CLI tool.
Therefore, if you are using one of these versions, we advise executing
dotnet build
before instrumenting the terminal session
or calling it in a separate terminal session.
See the Get started section for more information.
Error message similar to the one below:
Unhandled exception. System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.Extensions.DependencyInjection.Abstractions, Version=7.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'. The system cannot find the file specified.
File name: 'Microsoft.Extensions.DependencyInjection.Abstractions, Version=7.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'
at Microsoft.AspNetCore.Builder.WebApplicationBuilder..ctor(WebApplicationOptions options, Action`1 configureDefaults)
at Microsoft.AspNetCore.Builder.WebApplication.CreateBuilder(String[] args)
at Program.<Main>$(String[] args) in /Blog.Core/Blog.Core.Api/Program.cs:line 26
OpenTelemetry .NET NuGet packages and their dependencies are deployed with the OpenTelemetry .NET Automatic Instrumentation. To avoid dependency version conflicts, the recommended way to install the automatic instrumentation is using the NuGet packages. For instructions on how to add the packages to your application, and the limitations of this installation method, see Using the OpenTelemetry.AutoInstrumentation NuGet packages.
Alternatively, you can handle the dependency versions conflicts by updating the instrumented application's project references to use the same versions as OpenTelemetry .NET Automatic Instrumentation.
The following dependencies are used by OpenTelemetry .NET Automatic Instrumentation:
Find their versions in the following locations:
- Directory.Packages.props
- src/Directory.Packages.props
- src/OpenTelemetry.AutoInstrumentation.AdditionalDeps/Directory.Packages.props
By default, assembly references for .NET Framework applications are redirected
during runtime to the versions used by the automatic instrumentation.
This behavior can be controlled through the OTEL_DOTNET_AUTO_NETFX_REDIRECT_ENABLED
setting.
If the application already ships binding redirection for assemblies used by automatic instrumentation this automatic redirection may fail, see #2833. Check if any existing binding redirect prevent redirection to the versions listed at netfx_assembly_redirection.h.
For the automatic redirection above to work there are two specific scenarios that
require the assemblies used to instrument .NET Framework
applications, the ones under the netfx
folder of the installation directory,
to be also installed into the Global Assembly Cache (GAC):
- Monkey patch instrumentation of assemblies loaded as domain-neutral.
- Assembly redirection for strong-named applications if the app also ships
different versions of some assemblies also shipped in the
netfx
folder.
If you are having problems in one of the scenarios above run again the
Install-OpenTelemetryCore
command from the PowerShell installation module
OpenTelemetry.DotNet.Auto.psm1
to ensure that the required GAC installations
are updated.
For more information about the GAC usage by the automatic instrumentation, see here.
You get an error message similar to the following:
An assembly specified in the application dependencies manifest (OpenTelemetry.AutoInstrumentation.AdditionalDeps.deps.json) was not found
If you encounter an issue not listed on this page, see General steps to collect additional diagnostic information. This might help facilitate troubleshooting.
Applications may crash or behave unexpectedly due to version mismatches between the application's assemblies and those in the .NET runtime store. The RuntimeStoreDiagnosticRule in RuleEngine helps identify these mismatches by logging a warning if the application references a lower version than the runtime store.
Sample Diagnostic Output:
[Warning] Rule Engine: Application references lower version of runtime store assembly C:\path\to\assembly.dll - 6.0.0.0.
[Debug] Rule Engine: Runtime store assembly C:\path\to\assembly.dll validated successfully.
For resolving runtime store assembly version conflicts, follow the same solution as outlined for Assembly version conflicts in this document.