Final Update: Friday, 20 September 2019 10:04 UTC
We've confirmed that all systems are back to normal with no customer impact as of 09/20, 09:30 UTC. Our logs show the incident started on 09/19 05:30 UTC and that during the 28 hours that it took to resolve the issue some customers experienced would have experienced issues while accessing their data in the Azure Portal in West Central US and Australia South East regions. Query performance may also be degraded. Customers who have created Log Search Alerts in those regions could also have experienced alerting failures..
- Root Cause: The failure was due to an issue in one of our back-end components.
- Incident Timeline for West Central US: 28 Hours - 09/19, 05:30 UTC through 09/20, 09:30 UTC
- Incident Timeline for South East Australia: 3 Hours - 09/20, 06:00 UTC through 09/20, 09:00 UTC
We understand that customers rely on Azure Log Analytics as a critical service and apologize for any impact this incident caused.
-Varun