Application Insights TrackEvent only fires from constructor. Does not work in function

Question

In the following Azure function, TrackEvent only fires events from the constructor. TrackEvent calls from TestTelemetryFunc function are never fired.

The TestTelemetryFunc function is using a cached telemetry client received in the constructor.

public class TestApi
{
    private readonly TelemetryConfiguration telemetryConfiguration;
    private readonly TelemetryClient telemetryClient;
    private readonly TelemetryClient telemetryClientFromConfig;

    public TestApi(TelemetryConfiguration telemetryConfiguration, TelemetryClient telemetryClient)
    {
        this.telemetryConfiguration = telemetryConfiguration;
        this.telemetryClient = telemetryClient;

        this.telemetryClient.TrackEvent(new EventTelemetry("Constructor.telemetryClient"));

        this.telemetryClientFromConfig = new TelemetryClient(telemetryConfiguration);
        this.telemetryClientFromConfig.TrackEvent(new EventTelemetry("Constructor.telemetryClientFromConfig"));
    }

    [FunctionName("TestTelemetryFunc")]
    public async Task TestTelemetryFunc([HttpTrigger(AuthorizationLevel.Anonymous, "get", Route = "test-telemetry/site/{siteId}")] HttpRequest req, string siteId)
    {
        this.telemetryClient.TrackEvent(new EventTelemetry("TestTelemetryFunc.telemetryClient"));
        this.telemetryClientFromConfig.TrackEvent(new EventTelemetry("TestTelemetryFunc.telemetryClientFromConfig"));
    }
}

Application Insights Results

6/4/2021, 3:08:04 PM | IngestionApi.TestTelemetry.Constructor | customEvent | TestTelemetryFunc
6/4/2021, 3:08:04 PM | Constructor.telemetryClientFromConfig | customEvent | TestTelemetryFunc
6/4/2021, 3:08:04 PM | Constructor.telemetryClient | customEvent | TestTelemetryFunc
6/4/2021, 3:08:03 PM | IngestionApi.TestTelemetry.Constructor | customEvent | TestTelemetryFunc
6/4/2021, 3:08:03 PM | Constructor.telemetryClientFromConfig | customEvent | TestTelemetryFunc
6/4/2021, 3:08:03 PM | Constructor.telemetryClient | customEvent | TestTelemetryFunc
6/4/2021, 3:08:02 PM | IngestionApi.TestTelemetry.Constructor | customEvent | TestTelemetryFunc
6/4/2021, 3:08:02 PM | Constructor.telemetryClientFromConfig | customEvent | TestTelemetryFunc
6/4/2021, 3:08:02 PM | Constructor.telemetryClient | customEvent | TestTelemetryFunc
6/4/2021, 3:05:21 PM | IngestionApi.TestTelemetry.Constructor | customEvent | TestTelemetryFunc
6/4/2021, 3:05:21 PM | Constructor.telemetryClientFromConfig | customEvent | TestTelemetryFunc
6/4/2021, 3:05:21 PM | Constructor.telemetryClient | customEvent | TestTelemetryFunc
6/4/2021, 2:49:19 PM | IngestionApi telemetry client | customEvent | TestTelemetryFunc
6/4/2021, 2:49:19 PM | Constructor.telemetryClientFromConfig | customEvent | TestTelemetryFunc
6/4/2021, 2:49:19 PM | Constructor.telemetryClient | customEvent | TestTelemetryFunc

Answer 1

Got it to work.

Turned out the host.json settings were affecting the telemetry. Removed the entries with values of Warning below.

"logLevel": {
  "default": "Information",
  "Function": "Warning",
  "Host": "Warning",
  "Host.Results": "Warning",
  "Host.Aggregator": "Warning",
  "Host.Executor": "Warning",
  "Microsoft.EntityFrameworkCore": "Warning"
}

Answer 2

Hello @Carlos , glad that the issue is resolved now. For reference , https://learn.microsoft.com/en-us/azure/azure-functions/configure-monitoring?tabs=v2#configure-log-levels
you may configure the log level for customized result.