Stuck on an issue?

Lightrun Answers was designed to reduce the constant googling that comes with debugging 3rd party libraries. It collects links to all the places you might be looking at while hunting down a tough bug.

And, if you’re still stuck at the end, we’re happy to hop on a call to see how we can help out.

[BUG] [AzureMonitorExporter] Null Reference Exceptions at exporting logs

See original GitHub issue

Library name and version

Azure.Monitor.OpenTelemetry.Exporter 1.0.0-beta.7

Describe the bug

Null Reference Exceptions somewhere in exporting logs when running ASP.NET Core 7 web app.

OpenTelemetry-AzureMonitor-Exporter - EventId: [2], EventName: [WriteError], Message: [FailedToExport - System.NullReferenceException: Object reference not set to an instance of an object.
   at Azure.Monitor.OpenTelemetry.Exporter.Internals.LogsHelper.ExtractProperties(String& message, IDictionary`2 properties, IReadOnlyCollection`1 stateDictionary)
   at Azure.Monitor.OpenTelemetry.Exporter.Internals.LogsHelper.GetMessageAndSetProperties(LogRecord logRecord, IDictionary`2 properties)
   at Azure.Monitor.OpenTelemetry.Exporter.Models.MessageData..ctor(Int32 version, LogRecord logRecord)
   at Azure.Monitor.OpenTelemetry.Exporter.Internals.LogsHelper.OtelToAzureMonitorLogs(Batch`1 batchLogRecord, AzureMonitorResource resource, String instrumentationKey)
   at Azure.Monitor.OpenTelemetry.Exporter.AzureMonitorLogExporter.Export(Batch`1& batch)]

Expected behavior

Running WebApp without errors in logs

Actual behavior

Null Reference Exception during running ASP.NET Core v7 web apps.

OpenTelemetry-AzureMonitor-Exporter - EventId: [2], EventName: [WriteError], Message: [FailedToExport - System.NullReferenceException: Object reference not set to an instance of an object.
   at Azure.Monitor.OpenTelemetry.Exporter.Internals.LogsHelper.ExtractProperties(String& message, IDictionary`2 properties, IReadOnlyCollection`1 stateDictionary)
   at Azure.Monitor.OpenTelemetry.Exporter.Internals.LogsHelper.GetMessageAndSetProperties(LogRecord logRecord, IDictionary`2 properties)
   at Azure.Monitor.OpenTelemetry.Exporter.Models.MessageData..ctor(Int32 version, LogRecord logRecord)
   at Azure.Monitor.OpenTelemetry.Exporter.Internals.LogsHelper.OtelToAzureMonitorLogs(Batch`1 batchLogRecord, AzureMonitorResource resource, String instrumentationKey)
   at Azure.Monitor.OpenTelemetry.Exporter.AzureMonitorLogExporter.Export(Batch`1& batch)]

Reproduction Steps

ASP.NET Core 7 web app

Adding latest Azure.Monitor.OpenTelemetry.Exporter 1.0.0-beta.7 and OpenTelemetry nuget packages:

    <PackageVersion Include="OpenTelemetry" Version="1.4.0-rc.3" />
    <PackageVersion Include="OpenTelemetry.Contrib.Preview" Version="1.0.0-beta2" />
    <PackageVersion Include="OpenTelemetry.Exporter.Console" Version="1.4.0-rc.3" />
    <PackageVersion Include="OpenTelemetry.Exporter.Jaeger" Version="1.4.0-rc.3" />
    <PackageVersion Include="OpenTelemetry.Extensions.Hosting" Version="1.4.0-rc.3" />
    <PackageVersion Include="OpenTelemetry.Instrumentation.AspNetCore" Version="1.0.0-rc9.12" />
    <PackageVersion Include="OpenTelemetry.Instrumentation.Http" Version="1.0.0-rc9.12" />
    <PackageVersion Include="OpenTelemetry.Instrumentation.Quartz" Version="1.0.0-alpha.1" />
    <PackageVersion Include="OpenTelemetry.Instrumentation.SqlClient" Version="1.0.0-rc9.12" />

Adding OpenTelemetry and AzureMonitorLogExporter to ConfigureLogging

            return Host.CreateDefaultBuilder(args)
                .ConfigureWebHostDefaults(webBuilder => webBuilder.UseStartup<Startup>())
                .ConfigureLogging((context, builder) =>
                {
                    builder.AddOpenTelemetry(options =>
                    {
                        options.IncludeScopes = true;
                        options.ParseStateValues = true;
                        options.IncludeFormattedMessage = true;
                        options.AttachLogsToActivityEvent();
                        options.AddAzureMonitorLogExporter(o => o.ConnectionString = context.Configuration.GetValue<string>("ApplicationInsights:ConnectionString"));
                    });
                });

Run Webapp

Environment

Visual Studio 17.5 Preview 6 Visual Studio 17.4.4

.NET SDK:
 Version:   7.0.200-preview.22628.1
 Commit:    76bbaffad6

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.22621
 OS Platform: Windows
 RID:         win10-x64
 Base Path:   C:\Program Files\dotnet\sdk\7.0.200-preview.22628.1\

Host:
  Version:      7.0.2
  Architecture: x64
  Commit:       d037e070eb

.NET SDKs installed:
  6.0.301 [C:\Program Files\dotnet\sdk]
  6.0.302 [C:\Program Files\dotnet\sdk]
  7.0.102 [C:\Program Files\dotnet\sdk]
  7.0.200-preview.22628.1 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 6.0.5 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 6.0.7 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 6.0.12 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 6.0.13 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 7.0.0 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 7.0.2 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 6.0.0 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 6.0.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 6.0.7 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 6.0.12 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 6.0.13 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 7.0.0 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 7.0.2 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.WindowsDesktop.App 6.0.0 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 6.0.5 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 6.0.7 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 6.0.12 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 6.0.13 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 7.0.0 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 7.0.2 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

Other architectures found:
  arm64 [C:\Program Files\dotnet]
    registered at [HKLM\SOFTWARE\dotnet\Setup\InstalledVersions\arm64\InstallLocation]
  x86   [C:\Program Files (x86)\dotnet]
    registered at [HKLM\SOFTWARE\dotnet\Setup\InstalledVersions\x86\InstallLocation]

Environment variables:
  Not set

global.json file:
  Not found

Issue Analytics

State:
Created 7 months ago
Comments:6 (3 by maintainers)

Top GitHub Comments

1reaction

CSymescommented, Mar 8, 2023

@SaurabhSharma-MSFT, I was experiencing the same issue, and managed to form a small reproducable project, attached. log-test.zip

The bug originates (for me at least) when using structured logging with a variable that is null. e.g.

string a = null;
logger.LogInformation("A null: {NullValue}", a);

I’ve updated to the new beta.8 release of the library that released this morning, and it does indeed look like it addresses the issue. Thanks @TimothyMothra!

1reaction

pockicommented, Feb 13, 2023

I tried to build a minimal repro but the exception don’t happen there. The Exception is only thrown in a bigger project and I have to check which part or configuration causes the problem. It will take some time and I will come back later.

Thank you very much