We've confirmed that all systems are back to normal with no customer impact as of 03/03, 16:35 UTC. Our logs show the incident started on 03/03, 07:34 UTC and that during the 9 hours that it took to resolve the issue some customers using Azure Log Analytics who may have experienced intermittent data access issues and/or queries returning no data when accessing application data. Customers may also experience missing or delayed alerts
Root Cause: The root cause to be a configuration issue which was created due to a recent system upgrade designed to improve performance and resiliency. The system was introduced in parallel to our current system and created a configuration mismatch between the data query and metadata layers which service Log Analytics.
Incident Timeline: 9 Hours - 03/03, 07:34 UTC through 03/03, 16:35 UTC
We understand that customers rely on Azure Log Analytics as a critical service and apologize for any impact this incident caused.
Update: Wednesday, 03 March 2021 12:46 UTC
Root cause has been isolated to issues with one of the backend dependency. Engineers are currently working hard to resolve this. The data latency issue is already resolved. Some customers may continue to experience data gaps and incorrect alert activation in multiple regions.
Work Around: None
Next Update: Before 03/03 17:00 UTC
Initial Update: Wednesday, 03 March 2021 09:41 UTC
We are aware of issues within Log Analytics and are actively investigating. Some customers may have been experiencing intermittent data latency, data gaps and incorrect alert activation in Central India, Korea Central, East Asia, Southeast Asia and Australia East 2.
Next Update: Before 03/03 13:00 UTC
We are working hard to resolve this issue and apologize for any inconvenience. -Vyom