Apps on AKS don't send anything to Application Insights

Hi @Jörg Lang
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ensure that the Application Insights connection string (or instrumentation key) is properly configured in your AKS deployment. The communication string you use locally may not pass properly when sent to AKS. Double check that APPLICATIONINSIGHTS_CONNECTION_STRING is correctly defined in your AKS deployment YAML file, e.g. 

env: 

  - name: APPLICATIONINSIGHTS_CONNECTION_STRING 

    value: "InstrumentationKey=<your-instrumentation-key>" 

Verify that it matches the communication string running locally. 

Next, the application should be able to access Application Insights on the Internet. Sometimes network settings or firewalls can block a connection. You can verify this by running a quick test in one of your AKS pods. Example: 

curl -v https://dc.services.visualstudio.com 

If this command fails, it may indicate that there are network restrictions that need to be resolved. 

 If you use a managed identity for your AKS cluster, verify that the identity has the appropriate permissions to send telemetry to Application Insights. The monitoring contributor role for the managed identity must be assigned to the Application Insights object in the Azure portal. 

 In addition, Application Insights uses telemetry sampling by default, which limits the amount of data sent. If the sampling rate is set too low, you will not see any telemetry data. You can temporarily disable sampling in your application startup code to see if that is the problem. Example: 

services.AddApplicationInsightsTelemetry(Configuration["ApplicationInsights:ConnectionString"]); TelemetryConfiguration.Active.DefaultTelemetrySink.TelemetryProcessorChainBuilder. Use((next) => new MyTelemetryProcessor(next)); 

If your AKS environment is outside of a proxy, you must ensure that the proxy does not block telemetry traffic to Application Insights. This step can be skipped if no proxy is involved. 

 It’s also worth checking if you’re using the latest version of the Application Insights SDK. Sometimes an older SDK can cause problems. If you are not on the latest version, try updating the Application Insights SDK for ASP.NET Core. 

 Finally, make sure your AKS cluster has sufficient CPU and memory resources. If the cluster runs out of resources, it may affect the app's ability to send telemetry. 

 If none of these steps resolve the issue, you can enable the advanced telemetry feature in your application to capture additional information about diagnostic tests, which can help identify any issues with data a collected or shipped inside.

If you have any further queries, do let us know.

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