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Application Insights for Web Server not getting Telemetry or Live Metrics Data
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chunk
1
Reputation point
I did some digging to find that there was a certificate issue, along the lines of
Error: System.Net.Http.HttpRequestException: An error occurred while sending the request. ---> System.Net.WebException: The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel. ---> System.Security.Authentication.AuthenticationException: The remote certificate is invalid according to the validation procedure.
My other service instances show up in Azure App Insights just fine, only the Web instance is not showing. They both have the same certificates and security settings (Firewall off, no hardening enabled for dev). I think it may be that the App Insights Web Nuget package being the differentiator.
I did some testing to find that disabling cert validation on the Web source code works. Then I went to find that the "Digicert Global Root G2" was the certificate I was missing for the Web instance to send App Insights data. None of the other instances needs this cert, and "Digicert Global Root CA" exists already.
Was this caused from the Azure TLS cert changes from https://learn.microsoft.com/en-us/azure/security/fundamentals/tls-certificate-changes? Is there a way to check the .NET Microsoft.ApplicationInsights.Web Nuget package's TLS/SSL needs?
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SwathiDhanwada-MSFT 18,996 Reputation points Moderator2021-02-08T12:44:26.263+00:00 @chunk Thanks for your comment. Can you please provide below details to understand your issue better ?
- When you mention Web server , is your app hosted on app service or on an Azure VM ?
- Instrumentation that you are using to enable Application Insights (codeless attach or Code based )
- When did the issue begin ?
- Is the application insights enabled recently for the web server ?
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chunk 1 Reputation point
2021-02-08T16:08:37.997+00:00 Hi Swathi, see answers below:
- When you mention Web server , is your app hosted on app service or on an Azure VM ?
It's a standalone Windows Server machine that uses IIS to host our web service. - Instrumentation that you are using to enable Application Insights (codeless attach or Code based )
Code based. It is using the C# packages for App Insights, including the Microsoft.ApplicationInsights.Web Nuget package. - When did the issue begin ?
Not exactly sure. But we do have records of it working when we first developed it. - Is the application insights enabled recently for the web server ?
No, we have had it for some time. We just recently noticed the Live Metrics for it was missing.
- When you mention Web server , is your app hosted on app service or on an Azure VM ?
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SwathiDhanwada-MSFT 18,996 Reputation points Moderator
2021-03-05T12:49:37.827+00:00 @chunk Apologies for late response. Checking if your issue is resolved, If not, we recommend engaging our technical support team to investigate further. Please file a support case using these steps.
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