Azure Application Insights - No Such Host Is Known

Glenn Escarayan 141

Hi MS/Azure Team,

Anyone encounter this error " No Such Host Is Known" before when using Azure Application insights transactional search?

User's image

Any thoughts?

Thanks,

GCE

AnuragSingh-MSFT 21,551 Reputation points Moderator

2023-02-21T08:30:30.6033333+00:00
@Glenn Escarayan It looks like the error is coming from one of the methods in application, where an attempt is made to connect to a remote server. Based on the details of Socket Excption here, A SocketException is thrown by the Socket and Dns classes when an error occurs with the network.

I would suggest looking at the stack trace of exceptions to locate the method from where it originates. It should give you an idea of the remote host which it is not able to find or connect to. Adding additional logging to that method to log details of the remote server address (or taking network trace if you know the frequency of error) should help you understand if there is an issue

in the code

or the remote host is permanently or temporarily unavailable.

Hope this helps. Please let me know if you have any questions.
Glenn Escarayan 141 Reputation points

2023-02-23T06:35:13.3433333+00:00

Hello Anurag,

Thanks for the information. I will continue to investigate and let you know.

Regards,

GCE

1 answer

Glenn Escarayan 141 Reputation points

2023-02-24T01:53:29.42+00:00

Hello Anurag,

Upon further investigation, the error occurs between two web App service with VNET integration. I run the following steps to check:

Network Troubleshooting> Connection Issues> Both are resolving to its public IP addresses

Network Navigator: No network dependencies

Failed Request Tracing - No issue Found

WebApp1

WebApp2

Any advise?

Thanks,

GCE
Please sign in to rate this answer.

0 comments No comments
Sign in to comment

Use comments to ask for clarification, additional information, or improvements to the question.

Your answer