Application Insights-TelemetryClient-DependencyTelemetry-UseSampling

Posted 2021-04-11

我正在尝试通过我的AppInsightsHelper类启用采样，该类启动Depedancy操作以跟踪性能。

这是我初始化TelematryClient的方式：

 public ApplicationInsightsHelper(string key)
 {
        var config = TelemetryConfiguration.CreateDefault();
        config.InstrumentationKey = key;
        config.DefaultTelemetrySink.TelemetryProcessorChainBuilder.UseAdaptiveSampling(maxTelemetryItemsPerSecond: 1);

        _telemetryClient = new TelemetryClient(config);
 }

然后启动和停止操作：

   IOperationHolder<DependencyTelemetry> operation = null;
   operation = _telemetryClient.StartOperation<DependencyTelemetry>(friendlyName);
   operation.Telemetry.Name = friendlyName;
   operation.Telemetry.Type = type;
   operation.Telemetry.Timestamp = DateTime.UtcNow;

   operation.Telemetry.Duration = DateTime.UtcNow - operation.Telemetry.Timestamp;
   _telemetryClient.StopOperation(operation);

问题在于，上面的代码似乎忽略了Sampling设置，并且跟踪了所有操作。我还在UseAdaptiveSampling内包括了：excludeedTypes：“ Dependency”，以查看是否发生了任何事情，并且按预期，不忽略Dependencies。

答案

如果是天蓝色函数，则可以通过host.json设置采样，有关详细信息，请参见here和here。示例如下：

{
  "logging": {
    "applicationInsights": {
      "samplingSettings": {
        "isEnabled": true,
        "maxTelemetryItemsPerSecond" : 1
      }
    }
  }
}

并且如果您想使用TelemetryClient进行设置，则应遵循此article。在azure函数的构造函数中，使用如下代码：

        /// Using dependency injection will guarantee that you use the same configuration for telemetry collected automatically and manually.
        public HttpTrigger2(TelemetryConfiguration telemetryConfiguration)
        {
            this.telemetryClient = new TelemetryClient(telemetryConfiguration);
        }

但是到目前为止，使用遥测配置有issue。