Troubleshoot Azure Application Insights Agent (formerly Status Monitor v2)

Article
06/24/2024

This article provides troubleshooting information to help you resolve data collection issues that you might experience when Microsoft Azure Application Insights monitoring is enabled.

Known issues

Conflicting DLLs in the bin folder

If any of these dynamic-link libraries (DLLs) are present in the bin folder of the app, monitoring might fail:

Microsoft.ApplicationInsights.dll
Microsoft.AspNet.TelemetryCorrelation.dll
System.Diagnostics.DiagnosticSource.dll

Some of these DLLs are included in the Visual Studio default app templates, even if the app doesn't use them. You can use troubleshooting tools, such as the following tools, to see symptomatic behavior:

PerfView:

ThreadID="7,500" 
ProcessorNumber="0" 
msg="Found 'System.Diagnostics.DiagnosticSource, Version=4.0.2.1, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51' assembly, skipping attaching redfield binaries" 
ExtVer="2.8.13.5972" 
SubscriptionId="" 
AppName="" 
FormattedMessage="Found 'System.Diagnostics.DiagnosticSource, Version=4.0.2.1, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51' assembly, skipping attaching redfield binaries"

IISReset and app load (without telemetry). Investigate by using Sysinternals (Handle.exe and ListDLLs.exe):

.\handle64.exe -p w3wp | findstr /I "InstrumentationEngine AI. ApplicationInsights"
E54: File  (R-D)   C:\Program Files\WindowsPowerShell\Modules\Az.ApplicationMonitor\content\Runtime\Microsoft.ApplicationInsights.RedfieldIISModule.dll

.\Listdlls64.exe w3wp | findstr /I "InstrumentationEngine AI ApplicationInsights"
0x0000000009be0000  0x127000  C:\Program Files\WindowsPowerShell\Modules\Az.ApplicationMonitor\content\Instrumentation64\MicrosoftInstrumentationEngine_x64.dll
0x0000000009b90000  0x4f000   C:\Program Files\WindowsPowerShell\Modules\Az.ApplicationMonitor\content\Instrumentation64\Microsoft.ApplicationInsights.ExtensionsHost_x64.dll
0x0000000004d20000  0xb2000   C:\Program Files\WindowsPowerShell\Modules\Az.ApplicationMonitor\content\Instrumentation64\Microsoft.ApplicationInsights.Extensions.Base_x64.dll

PowerShell versions

This product was written and tested by using PowerShell version 5.1. This module isn't compatible with PowerShell versions 6 or 7. We recommend that you use PowerShell 5.1 alongside newer versions. For more information, see Using PowerShell 7 side-by-side with PowerShell 5.1.

Conflict in IIS shared configuration

If you have a cluster of web servers, you might be using a shared configuration. The HTTP module can't be injected into this shared configuration. Run the Enable command on each web server to install the DLL into each server's global assembly cache (GAC).

After you run the Enable command, follow these steps:

Go to the shared configuration directory and locate the ApplicationHost.config file.

Add the following XML code to the <modules> section of your configuration:

<modules>
    <!-- Registered global managed http module handler. The 'Microsoft.AppInsights.IIS.
    ManagedHttpModuleHelper.dll' must be installed in the GAC before this config is applied. -->
    <add name="ManagedHttpModuleHelper" type="Microsoft.AppInsights.IIS.ManagedHttpModuleHelper.
    ManagedHttpModuleHelper, Microsoft.AppInsights.IIS.ManagedHttpModuleHelper, Version=1.0.0.0, 
    Culture=neutral, PublicKeyToken=31bf3856ad364e35" preCondition="managedHandler,runtimeVersionv4.0" />
</modules>

IIS nested applications

In version 1.0 of the Application Insights Agent, we don't instrument nested applications in Internet Information Services (IIS).

IIS classic pipeline mode

We don't instrument applications that are hosted on application pools if they're configured to use the classic pipeline mode.

Advanced SDK configuration isn't available

The SDK configuration isn't exposed to the end user in version 1.0.

Troubleshoot PowerShell

Determine which modules are available

To determine which modules are installed, run the Get-Module -ListAvailable cmdlet.

Import a module into the current session

If a module isn't loaded into a PowerShell session, you can manually load it by running the Import-Module <path-to-psd1> cmdlet.

Troubleshoot the Application Insights Agent module

List the cmdlets available in the Application Insights Agent module

To see the cmdlets that are available in the Application Insights Agent module, run the Get-Command -Module Az.ApplicationMonitor cmdlet:

CommandType     Name                                               Version    Source
-----------     ----                                               -------    ------
Cmdlet          Disable-ApplicationInsightsMonitoring              0.4.0      Az.ApplicationMonitor
Cmdlet          Disable-InstrumentationEngine                      0.4.0      Az.ApplicationMonitor
Cmdlet          Enable-ApplicationInsightsMonitoring               0.4.0      Az.ApplicationMonitor
Cmdlet          Enable-InstrumentationEngine                       0.4.0      Az.ApplicationMonitor
Cmdlet          Get-ApplicationInsightsMonitoringConfig            0.4.0      Az.ApplicationMonitor
Cmdlet          Get-ApplicationInsightsMonitoringStatus            0.4.0      Az.ApplicationMonitor
Cmdlet          Set-ApplicationInsightsMonitoringConfig            0.4.0      Az.ApplicationMonitor
Cmdlet          Start-ApplicationInsightsMonitoringTrace           0.4.0      Az.ApplicationMonitor

Determine the current version of the Application Insights Agent module

Run the Get-ApplicationInsightsMonitoringStatus -PowerShellModule cmdlet to display the following information about the module:

PowerShell module version
Application Insights SDK version
File paths of the PowerShell module

Review the Get-ApplicationInsightsMonitoringStatus reference for a detailed description of how to use this cmdlet.

Troubleshoot running processes

You can inspect the processes on the instrumented computer to determine whether all DLLs are loaded and environment variables are set. If monitoring is working, at least 12 DLLs should be loaded.

Run the Get-ApplicationInsightsMonitoringStatus -InspectProcess cmdlet to check the DLLs.
Run the (Get-Process -id <process-identifier>).StartInfo.EnvironmentVariables cmdlet to check the environment variables. The following environment variables are set in the worker process or the .NET Core process:

COR_ENABLE_PROFILING=1
COR_PROFILER={324F817A-7420-4E6D-B3C1-143FBED6D855}
COR_PROFILER_PATH_32=<path-to-MicrosoftInstrumentationEngine_x86.dll>
COR_PROFILER_PATH_64=<path-to-MicrosoftInstrumentationEngine_x64.dll>
MicrosoftInstrumentationEngine_Host={CA487940-57D2-10BF-11B2-A3AD5A13CBC0}
MicrosoftInstrumentationEngine_HostPath_32=<path-to-Microsoft.ApplicationInsights.ExtensionsHost_x86.dll>
MicrosoftInstrumentationEngine_HostPath_64=<path-to-Microsoft.ApplicationInsights.ExtensionsHost_x64.dll>
MicrosoftInstrumentationEngine_ConfigPath32_Private=<path-to-Microsoft.InstrumentationEngine.Extensions.config>
MicrosoftInstrumentationEngine_ConfigPath64_Private=<path-to-Microsoft.InstrumentationEngine.Extensions.config>
MicrosoftAppInsights_ManagedHttpModulePath=<path-to-Microsoft.ApplicationInsights.RedfieldIISModule.dll>
MicrosoftAppInsights_ManagedHttpModuleType=Microsoft.ApplicationInsights.RedfieldIISModule.RedfieldIISModule
ASPNETCORE_HOSTINGSTARTUPASSEMBLIES=Microsoft.ApplicationInsights.StartupBootstrapper
DOTNET_STARTUP_HOOKS=<path-to-Microsoft.ApplicationInsights.StartupHook.dll>