Experiencing Data latency Issue in Azure portal for Log Analytics EUS2 - 02/16 - Resolved

[Azure-Monitor-Team]

Final Update: Wednesday, 17 February 2021 00:40 UTC

We've confirmed that all systems are back to normal with no customer impact as of 2/17, 00:20 UTC. Our logs show the incident started on 2/16, 19:45 UTC and that during the ~4 hours 25 min hours that it took to resolve the issue, customers in East US2 experienced data gaps and incorrect alert activation.

• Root Cause: The failure was due to one of the backend services becoming unhealthy due to incorrect configuration which was impacting telemetry ingestion into Log analytics workspaces.
• Incident Timeline: 4 Hours & 25 minutes - 2/16, 19:45 UTC through 2/17, 00:20 UTC

We understand that customers rely on Azure Log Analytics as a critical service and apologize for any impact this incident caused.

-Anupama

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Update: Tuesday, 16 February 2021 23:39 UTC

Root cause has been isolated to one of the backend services becoming unhealthy due to incorrect configuration which was impacting telemetry ingestion into Log analytics workspaces. To address this issue backend service was upgraded to use correct configuration. Some customers may experience data gaps and incorrect alert activation. Currently the latent data is being recovered.

• Work Around:  None
• Next Update: Before 02/17 02:00 UTC

-Anupama

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Update: Tuesday, 16 February 2021 22:13 UTC

We continue to investigate issues within Log Analytics in East US2 region. Root cause is not fully understood at this time. Some customers ingesting telemetry in their Log Analytics workspaces in East US 2 may experience intermittent data latency, data gaps and incorrect alert activation. We are working to establish the start time for the issue, initial findings indicate that the problem began at 2020-02-16 19:45 UTC. We currently have no estimate for resolution.

• Work Around: None
• Next Update: Before 02/17 00:30 UTC

-Anupama

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