Azure Function - Internal server error

Question

We have an Azure Function (Runtime V3) running a .NET Core 3.1 application.
On several occasions, we receive HTTP Status code 500 Internal Server Error when executing HTTP Functions.
I've looked in several logs (AppInsights Exceptions, Log System, Kudu => Host Logfiles) but have not been able to find the root cause of the error. It's running on the Consumption plan so it could potentially be a 'noisy neighbor'. The local debugging works fine. But running on Azure (both via API call or test/Run in Function app blade) fails.

Is there some other log where I could find the actual root cause of the error?

Answer 1

@Anshul_7275 Welcome to Microsoft Q&A Forum, Thank you for posting your query here!

I understand that you are encountering HTTP Status code 500 Internal Server Error when executing HTTP Functions. You have already looked in several logs (AppInsights Exceptions, Log System, Kudu => Host Logfiles) but have not been able to find the root cause of the error.

Please follow the below action plan:

1. Please check Functions metrics for the HTTP Server Errors at the time of the issue.

1. Please check the Function App detectors by navigating to the Diagnose and Solve Problems section in the Azure Portal for the Functions as shown below: You can rely on the Function App Down or Reporting Errors option and the Function App Health Check option as shown below:

More Info here.

3. You can also query the FunctionLogs as shown below:

More Info here.

Note: If none of the above steps help, Please share the below details over an email at AzCommunity@microsoft.com ( with subject "Attn: Naveen") and include the below details:

• Your Azure Function Name
• You Azure Function App resource URI in below format: /subscriptions/XXXXXXXXXX/resourceGroups/XXXXXX/providers/Microsoft.Web/sites/XXXXXX
• Most recent UTC time of the actual issue where you received HTTP 500 error

I will look at the backend logs to identify the root cause.

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