What could be causing intermittent connection timeouts in my Azure .NET API?

Below are a few suggestions to investigate:

1. Diagnostics and Telemetry
   • Ensure that your API is using a supported Application Insights SDK so that the telemetry is properly correlated.
   • Verify that Application Insights is collecting dependency information (and that any missing dependencies are manually tracked if necessary).
   • Double-check that the cloud role name is correctly configured so that the telemetry properly associates requests with your API.

2. Connection Behavior and Keep-Alive
   • When you run a curl script continuously, the failure every 30–60 seconds might indicate that idle connections are timing out. Consider checking your API’s keep-alive settings and any container networking idle timeout configurations.
   • In rapid 5000 call bursts, connection reuse or pooling might not be a factor; but in continuous sequential calls, stale connections could be getting dropped. Testing with curl’s --keepalive-time parameter or disabling keep-alive may help isolate the behavior.

3. Networking and Load Balancing
   • Review any networking configurations around your container app. For instance, if your app is behind a load balancer or using NAT, intermittent connection drops (when idle connections are closed) could be expected.
   • Check whether the issue coincides with any resource scaling events or transient networking issues that might not immediately show up in the application logs.

4. Enhanced Logging and Application Map
   • Enable more verbose logging (if not already done) to capture transient exceptions.
   • Use Application Map in Azure Monitor to verify if there are any hidden dependency or connectivity issues that might not show up in standard logs.

By systematically checking these areas, you should be able to identify whether the issue is due to configuration (such as idle connection timeouts or misconfigured telemetry) or transient networking glitches that occur under continuous test scenarios. Let me know if you need further details on any of these steps.