Azure Application Insights 不显示在 Azure 函数中创建的自定义事件

Question

我有一个用 C# 编写的函数应用程序，它是在 Azure 中创建的，由 HttpTrigger 触发。

我正在尝试记录几个自定义事件来记录分析性能的有趣时间点。

我所做的是在构造函数中创建 TelemetryClient。

  static ThumbnailGenerator()
    {
        telemetryClient = new TelemetryClient(TelemetryConfiguration.CreateDefault());
    }

然后在函数中：

    [FunctionName("Upload")]
    [StorageAccount("AzureWebJobsStorage")]
    public static async Task<IActionResult> Upload(
        [HttpTrigger(AuthorizationLevel.Anonymous, "get", "post", Route = "upload/{name}")] HttpRequest req,
        string name,
        ILogger log,
        ExecutionContext context)
    {       
        var evt = new EventTelemetry("Upload function called");
        evt.Context.User.Id = name;
        telemetryClient.TrackEvent(evt);
        telemetryClient.Flush();

        ....

        DateTime start = DateTime.UtcNow;
    
        // Log a custom dependency in the dependencies table.
        var dependency = new DependencyTelemetry
        {
            Name = "Upload-Image-Operation",
            Timestamp = start,
            Duration = DateTime.UtcNow - start,
            Success = true
        };

        telemetryClient.TrackDependency(dependency);
        telemetryClient.Flush();

        return new OkObjectResult(name + "Uploaded successfully.");
    }

此应用程序见解可以始终正确显示函数的默认 RequestTelemetry 和跟踪。但是，自定义事件和DependencyTelemetry 非常不稳定，有时在应用程序洞察中显示，有时根本不显示。

我做了很多研究并添加了如下内容：

    telemetryClient.Flush();

但不稳定的情况还是差不多。

我使用的库是：

 <Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>netcoreapp3.1</TargetFramework>
    <AzureFunctionsVersion>v3</AzureFunctionsVersion>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Azure.Storage.Blobs" Version="12.9.0" />
    <PackageReference Include="Microsoft.ApplicationInsights" Version="2.14.0" />
    <PackageReference Include="Microsoft.Azure.WebJobs.Extensions.Storage" Version="5.0.0-beta.2" />
    <PackageReference Include="Microsoft.Azure.WebJobs.Logging.ApplicationInsights" Version="3.0.25" />
    <PackageReference Include="Microsoft.NET.Sdk.Functions" Version="3.0.11" />
    <PackageReference Include="SixLabors.ImageSharp" Version="1.0.3" />
    <PackageReference Include="System.Diagnostics.DiagnosticSource" Version="5.0.1" />
  </ItemGroup>
  <ItemGroup>
    <None Update="host.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
    </None>
    <None Update="local.settings.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
      <CopyToPublishDirectory>Never</CopyToPublishDirectory>
    </None>
  </ItemGroup>
</Project>

有人知道为什么吗？看来 Azure 在这部分真的很不稳定而且有问题。请给我一些提示。

Answer 1

您可能运行进入 Sampling feature of Application Insights。

[Sampling] is the recommended way to reduce telemetry traffic, data costs, and storage costs, while preserving a statistically correct analysis of application data.

This page 还有一些特定于 Azure Functions 的更多详细信息：

When the rate of incoming executions exceeds a specified threshold, Application Insights starts to randomly ignore some of the incoming executions.

这听起来像是您遇到的行为。您可以使用 host.json 文件来配置哪些类型的遥测被排除在采样之外；尝试将 Event 添加到 excludedTypes:

{
  "logging": {
    "applicationInsights": {
      "samplingSettings": {
        "isEnabled": true,
        "maxTelemetryItemsPerSecond" : 20,
        "excludedTypes": "Request;Exception;Event"
      }
    }
  }
}

Answer 2

确保您的遥测配置设置了正确的检测密钥。我不确定 TelemetryConfiguration.CreateDefault() 得到了正确的值。

此外，我建议使用依赖注入在构造函数中注入 TelemetryClient。它已经开箱即用。这样您就不必自己创建实例，也不必担心设置检测密钥的正确方法：

    [FunctionName("Upload")]
    [StorageAccount("AzureWebJobsStorage")]
    public static async Task<IActionResult> Upload(
        [HttpTrigger(AuthorizationLevel.Anonymous, "get", "post", Route = "upload/{name}")] HttpRequest req,
        string name,
        ILogger log,
        TelemetryClient telemetryClient, 
        ExecutionContext context)
    {       
        telemetryClient.XXX();
        ...
    }

刷新客户端应该不是必需的，只有在终止时才需要，即使这样你也应该等待一段时间，因为它是一个异步进程。

Azure Application Insights 不显示在 Azure 函数中创建的自定义事件

Azure Application Insights doesn't show custom events created in Azure function

c#

azure

azure-application-insights

azure-functions