We've confirmed that all systems are back to normal with no customer impact as of 01/09, 19:18 UTC. Our logs show the incident started on 01/09, 18:30 UTC and that during the 48 minutes that it took to resolve the issue some customers in West Europe may experienced issues with data access in Azure portal, Query failures for Log Analytics and delayed or missed alerts in Log Search Alerts.
Root Cause: The failure was due to issue in one of the backend services.
Incident Timeline: 46 minutes - 01/09, 18:30 UTC through 01/09, 19:18 UTC
We understand that customers rely on Azure Log Analytics as a critical service and apologize for any impact this incident caused.
Initial Update: Thursday, 09 January 2020 19:14 UTC
We are aware of issues within Log Analytics and are actively investigating. Some customers in West Europe may experience issues with data access from portal or query failures in Azure Log Analytics.
Next Update: Before 01/09 23:30 UTC
We are working hard to resolve this issue and apologize for any inconvenience. -Jayadev