All of the telemetry for last 9 hours missing on our appinsights log instance

Question

All of the telemetry for last 9 hours missing on our appinsights log instance

Smriti Panwar 20 Microsoft Employee

No telemetry has been recorded on our Appinsights log for last 9 hours. No configuration changes have been made; we are using the correct instrumentation ids. It has not crossed the 100GB/day usage limit. For last day it's showing 2GB. What is wrong?

Bharath Y P 9,815 Reputation points Microsoft External Staff Moderator

2026-05-29T17:09:26.27+00:00

Hello Smriti, thank you for posting your query on Microsoft Q&A platform.

We are looking into your issue and will keep you posted updates.

Thanks
Bharath Y P 9,815 Reputation points Microsoft External Staff Moderator

2026-05-29T17:43:49.0066667+00:00
Hello Smriti, you’re seeing no telemetry in Application Insights for ~9 hours, despite of No config changes, Correct instrumentation key and not hitting daily cap (only ~2 GB used vs 100 GB limit).

Based on our internal checks, this behavior aligns with an ongoing platform-side issue affecting Application Insights ingestion.

We have identified active incidents in Azure where:

Telemetry ingestion into Application Insights and Log Analytics has been delayed or temporarily halted

Customers observed zero data in Logs despite applications continuing to run normally

Backend ingestion services are experiencing processing errors and delays affecting telemetry availability

Due to this issue:

Telemetry may not appear in Application Insights during the affected time window

Data ingestion may be delayed or appear after a backlog is processed, once the platform stabilizes.

The issue is currently under investigation by the Azure engineering team. This is a service-side (platform) issue, and no changes are required from your side at this time.

Please continue to monitor your Application Insights resource. You may check Azure Service Health for any related updates. Once the issue is mitigated, telemetry is expected to gradually resume and backfill (if applicable).

Reference: https://azure.status.microsoft/en-us/status
Smriti Panwar 20 Reputation points Microsoft Employee

2026-06-03T20:05:01.1766667+00:00

Yes but we had none of the above issue, It was a problem for us due to an outage in West2 region. It automatically resolved in few hours
Bharath Y P 9,815 Reputation points Microsoft External Staff Moderator

2026-06-04T02:06:10.44+00:00

Hello Smriti, Thanks for the update, hope your issue is resolved now, If the information was useful, please consider accepting the answer and upvoting. Please let us know if you need any assistance on this, Thanks

Answer accepted by question author

AI answer

Use a step-by-step check along the telemetry pipeline to find where data stopped flowing.

Verify ingestion endpoint and authentication

If the Application Insights data collection endpoint is configured to use Microsoft Entra ID, and the application is still sending with only an instrumentation key/connection string, telemetry will be rejected and not appear in the portal even though the app is running.
Confirm whether Microsoft Entra ID authentication was enabled on the Application Insights resource. If so, configure the app to authenticate accordingly as described in Enable Microsoft Entra ID (formerly Azure AD) authentication.

Check for SDK/agent misconfiguration

Missing telemetry can be caused by misconfigured SDK or agent, even if no intentional changes were made (for example, a deployment that changed environment variables or connection strings).
Validate that the Application Insights SDK/agent is still enabled and using the correct connection string/ikey, and that the host is configured according to the language-specific guidance.

Test connectivity from the host

From the application host, send test telemetry to the ingestion endpoint using PowerShell or curl as described in the troubleshooting guidance.
If these tests fail, investigate:
- DNS resolution of the ingestion endpoint.
- Firewalls or gateways blocking TCP connections to the ingestion endpoint.
- TLS version mismatch (endpoint requires TLS 1.2 while the app uses TLS 1.0/1.1).
- Azure Monitor Private Link or DNS overrides that may be resolving the ingestion endpoint to the wrong private IP.

Check for backend rejection or throttling

Even if usage is below the daily 100 GB limit, telemetry can still be dropped or throttled per-minute or due to service health issues.
Use an HTTP inspection tool (for example, Fiddler) or SDK logs to confirm that telemetry uploads are returning HTTP 200 from the backend. If not, data may be rejected due to missing required fields, oversized fields, or other validation issues.

Consider service health and query issues

Telemetry can be delayed or missing in the portal if:
- The ingestion pipeline is degraded due to service health issues.
- Log Analytics has problems saving records (uncommon).
- The query API (api.applicationinsights.io) is failing when retrieving data (uncommon).
Check Azure Service Health for any incidents affecting Application Insights or Log Analytics in the region.

If using App Service integration

For App Service with codeless monitoring, confirm:
- ApplicationInsightsAgent_EXTENSION_VERSION is correctly set (~2 or ~3 depending on OS/runtime).
- The Application Insights extension status page shows the extension running and IKeyExists = True.
- The status file path exists and indicates the app is running.
If the app also references Application Insights SDK packages, ensure Interop with Application Insights SDK is configured as required; otherwise, telemetry may be disabled.

If telemetry tests from the host succeed but nothing appears in the portal, and there are no service health issues, open a support case specifying Application Insights and include correlation IDs from failed or delayed requests so the ingestion pipeline can be investigated.

References:

AI-generated content may be incorrect. Read our transparency notes for more information.

1 additional answer

Your answer

Bharath Y P 9,815 Reputation points Microsoft External Staff Moderator

2026-05-29T17:09:26.27+00:00

Hello Smriti, thank you for posting your query on Microsoft Q&A platform.

We are looking into your issue and will keep you posted updates.

Thanks
Bharath Y P 9,815 Reputation points Microsoft External Staff Moderator

2026-05-29T17:43:49.0066667+00:00

Hello Smriti, you’re seeing no telemetry in Application Insights for ~9 hours, despite of No config changes, Correct instrumentation key and not hitting daily cap (only ~2 GB used vs 100 GB limit).

Based on our internal checks, this behavior aligns with an ongoing platform-side issue affecting Application Insights ingestion.

We have identified active incidents in Azure where:

Telemetry ingestion into Application Insights and Log Analytics has been delayed or temporarily halted

Customers observed zero data in Logs despite applications continuing to run normally

Backend ingestion services are experiencing processing errors and delays affecting telemetry availability

Due to this issue:

Telemetry may not appear in Application Insights during the affected time window

Data ingestion may be delayed or appear after a backlog is processed, once the platform stabilizes.

The issue is currently under investigation by the Azure engineering team. This is a service-side (platform) issue, and no changes are required from your side at this time.

Please continue to monitor your Application Insights resource. You may check Azure Service Health for any related updates. Once the issue is mitigated, telemetry is expected to gradually resume and backfill (if applicable).

Reference: https://azure.status.microsoft/en-us/status
Smriti Panwar 20 Reputation points Microsoft Employee

2026-06-03T20:05:01.1766667+00:00

Yes but we had none of the above issue, It was a problem for us due to an outage in West2 region. It automatically resolved in few hours
Bharath Y P 9,815 Reputation points Microsoft External Staff Moderator

2026-06-04T02:06:10.44+00:00

Hello Smriti, Thanks for the update, hope your issue is resolved now, If the information was useful, please consider accepting the answer and upvoting. Please let us know if you need any assistance on this, Thanks

Answer 1

Bharath Y P 9,815 Microsoft External Staff Moderator

Hello Smriti, Just checking to see, If the information shared was helpful, please accept the answer and upvote. Please feel free to reach out if you have any additional questions or need further clarification. Thanks

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All of the telemetry for last 9 hours missing on our appinsights log instance

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