Final Update: Wednesday, 23 October 2019 03:52 UTC
We've confirmed that all systems are back to normal with no customer impact as of 10/23, 00:23 UTC. Our logs show the incident started on 10/22, 21:15 UTC and that during the 3 hours that it took to resolve the issue some customer customers may have experienced data latency and data access issues.
Root Cause: The failure was due to a failure with an Azure Storage stamp in West Europe.
Incident Timeline: 3 Hours & 8 minutes - 10/22, 21:15 UTC through 10/23, 00:23 UTC
We understand that customers rely on Azure Log Analytics as a critical service and apologize for any impact this incident caused.
Update: Tuesday, 22 October 2019 21:58 UTC
Root cause has been isolated to a problem with an Azure Storage stamp in West Europe which is impacting Log Analytics query, Log Search Alert, and Metric Alerts. The Azure Storage team is actively working on a mitigation for this issue. Some customers may experience data latency, alert latency and problems with data access.