We've confirmed that all systems are back to normal with no customer impact as of 12/03, 13:30 UTC. Our logs show the incident started on 12/03, 09:30 UTC and that during the 4 hours that it took to resolve the issue some of the customers experienced data access issue in Azure and OMS Portal for Log Analytics..
Root Cause: The failure was due to the issues in one of our dependent service.
Incident Timeline: 4 Hours - 12/03, 09:30 UTC through 12/03, 13:30 UTC
We understand that customers rely on Azure Log Analytics as a critical service and apologize for any impact this incident caused.
Update: Monday, 03 December 2018 12:44 UTC
We continue to investigate issues within Log Analytics. Some customers in Europe region may experience data access issue in Azure and OMS Portal for Log Analytics.