We've confirmed that all systems are back to normal with no customer impact as of 01/06, 15:50 UTC. Our logs show the incident started on 01/06, 14:49 UTC and that during the 1 hour that it took to resolve the issue some customers in West Europe experienced issues with data access in the Azure portal, query failures for Log Analytics and alerting failures for Log Search Alerts.
Root Cause: The failure was due to one of the backend services being impacted.
Incident Timeline: 1 hour - 01/06, 14:49 UTC through 01/06, 15:50 UTC
We understand that customers rely on Azure Log Analytics as a critical service and apologize for any impact this incident caused.
Initial Update: Monday, 06 January 2020 15:28 UTC
We are aware of issues within Log Analytics and are actively investigating. Some customers in West Europe may experience data access issue in the Azure portal and failures when queried through API.
Next Update: Before 01/06 18:30 UTC
We are working hard to resolve this issue and apologize for any inconvenience. -Monish