Missing app service logs

Question

Missing app service logs

Pavel Orlov 0

Hello, App service is connected to AppInsights, Logs workspace shows logs being collected but when trying to query and retrieve the logs for App service/insights there's no data available for any query types or directly in App insights.

Thanks

Pavel

Sai Prabhu Naveen Parimi 3,965 Reputation points Microsoft External Staff Moderator

2025-02-11T23:14:31.95+00:00
Pavel Orlov

Welcome to the Microsoft Q&A Platform!

Thank you for reaching out.

If logs are not appearing in Application Insights, please follow these troubleshooting steps:

Check Diagnostic Settings to ensure logs are correctly routed to Application Insights and/or Log Analytics.

Verify the instrumentation key/configuration to confirm proper integration.

Ensure that the application is actively generating telemetry.

Check if sampling or filtering is affecting data collection.

For detailed guidance, please refer to this Microsoft documentation: https://learn.microsoft.com/en-us/troubleshoot/azure/azure-monitor/app-insights/telemetry/investigate-missing-telemetry

Let us know if you need further assistance.
Sai Prabhu Naveen Parimi 3,965 Reputation points Microsoft External Staff Moderator

2025-02-11T23:15:53.0266667+00:00

Duplicate comment has been deleted.
Harshitha Veeramalla 1,306 Reputation points Microsoft External Staff Moderator

2025-02-12T05:46:44.2233333+00:00

@Pavel Orlov What is the query you are trying to retrieve the data from ? Did you configure Application Insights for the app through code or manually?
Harshitha Veeramalla 1,306 Reputation points Microsoft External Staff Moderator

2025-02-12T05:48:13.6033333+00:00

@Pavel Orlov To confirm that you are getting the logs, check the Transaction search in Application Insights for the traces.

2 answers

Your answer

Sai Prabhu Naveen Parimi 3,965 Reputation points Microsoft External Staff Moderator

2025-02-11T23:14:31.95+00:00

Pavel Orlov

Welcome to the Microsoft Q&A Platform!

Thank you for reaching out.

If logs are not appearing in Application Insights, please follow these troubleshooting steps:

Check Diagnostic Settings to ensure logs are correctly routed to Application Insights and/or Log Analytics.

Verify the instrumentation key/configuration to confirm proper integration.

Ensure that the application is actively generating telemetry.

Check if sampling or filtering is affecting data collection.

For detailed guidance, please refer to this Microsoft documentation: https://learn.microsoft.com/en-us/troubleshoot/azure/azure-monitor/app-insights/telemetry/investigate-missing-telemetry

Let us know if you need further assistance.
Sai Prabhu Naveen Parimi 3,965 Reputation points Microsoft External Staff Moderator

2025-02-11T23:15:53.0266667+00:00

Duplicate comment has been deleted.
Harshitha Veeramalla 1,306 Reputation points Microsoft External Staff Moderator

2025-02-12T05:46:44.2233333+00:00

@Pavel Orlov What is the query you are trying to retrieve the data from ? Did you configure Application Insights for the app through code or manually?
Harshitha Veeramalla 1,306 Reputation points Microsoft External Staff Moderator

2025-02-12T05:48:13.6033333+00:00

@Pavel Orlov To confirm that you are getting the logs, check the Transaction search in Application Insights for the traces.

Answer 1

Pavel Orlov 0

Thanks for all the suggestions. But it's all been tried and there is simply no data returned when querying the logs or checking appinsights. The logging is on, logs workspace show graphs with data being ingested, appinsights connected etc. I'll do all the screenshots shortly so you can see.

I'm thinking if ASE v2 moving to v3 has anything to do with it though. The app service is in ASE behind app gateway.

Bhargavi Naragani 7,940 Reputation points Moderator

2025-02-12T08:47:29.8333333+00:00
If your App Service (ASE v3) behind App Gateway is not displaying logs in Application Insights,

From within your App Service, check if telemetry can reach App Insights

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

If access is blocked, set up Private Link Access or Service Endpoints for outbound access.

Check Diagnostic Settings in Azure Portal

App Service → Monitoring → Diagnostic Settings

Make sure logs are going to:

Log Analytics Workspace

Application Insights

If they're already on, try turning diagnostics off and on again.

Even if App Insights UI shows no data, check the Log Analytics Workspace:

AppTraces | where TimeGenerated > ago(1h)

If logs appear here but not in App Insights, adjust query scope in App Insights.

ASE v3 is isolated by default—verify outbound access to

dc.services.visualstudio.com live.applicationinsights.azure.com

Use NSG Flow Logs to see if egress traffic is being blocked.

Enable App Gateway Access Logs via: App Gateway → Monitoring → Diagnostic settings → Log Analytics

Look for dropped requests or failures that might prevent logs from reaching App Insights.

Deploy the same App Service outside ASE and check log collection.

If logs show up only outside ASE, then the issue is likely network restrictions or ASE-specific settings.

If logs are ingested but not queryable, it could indicate an ASE v3 → App Insights integration issue.

Share screenshots of your Log Analytics queries, App Insights settings, and ASE networking rules for further analysis.

Monitor Azure App Service

If you have any further assistance let me know.
Bhargavi Naragani 7,940 Reputation points Moderator

2025-02-13T08:48:36.6133333+00:00

Hi @Pavel Orlov,
We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. In case if you have any resolution, please do share that same with the community as it can be helpful to others. Otherwise, will respond with more details and we will try to help.
Bhargavi Naragani 7,940 Reputation points Moderator

2025-02-14T06:38:33.52+00:00

Hi @Pavel Orlov,
We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. In case if you have any resolution, please do share that same with the community as it can be helpful to others. Otherwise, will respond with more details and we will try to help.

Answer 2

Hi @Pavel Orlov,
Thanks for the question and using MS Q&A platform.
If your App Service is hooked up to Application Insights and you see logs in the Log workspace, but nothing shows up when you query,

Make sure the time range for your queries is correct. Logs might not show up if the selected time range doesn't cover the log generation time.

Ensure the connection strings in your Application Insights configuration match those in the Azure portal. Mismatched strings can block log visibility. Run your app in debug mode in Visual Studio to generate telemetry.

Check the Visual Studio output window for logged events. Data might take a bit to appear. Refresh the Application Insights portal to see if logs show up after a short delay. In the Azure portal, check Service Health for any alerts that might be affecting log availability.

Reference:

https://learn.microsoft.com/en-us/answers/questions/1348145/azure-application-insights-not-showing-logs

Troubleshoot no data: Application Insights for .NET and .NET Core

Monitor Azure App Service

If you have any further assistance let me know.

If the answer is helpful, please click Accept Answer and kindly upvote it so that other people who faces similar issue may get benefitted from it.

Pavel Orlov 0 Reputation points

2025-02-12T07:46:00.8+00:00

Thanks for all the suggestions. But it's all been tried and there is simply no data returned when querying the logs or checking appinsights. The logging is on, logs workspace show graphs with data being ingested, appinsights connected etc. I'll do all…

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Missing app service logs

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