Final Update: Thursday, 13 December 2018 22:18 UTC. This is a retroactive notification for an incident in Application Insights.
We've confirmed that all systems are back to normal as of 12/13, 10:54 UTC. Our logs show the incident started on 12/13, 08:50 UTC and that during the 2 hours and 4 minutes that it took to resolve the issue, some customers in East US region would have experienced data access issues in Azure Portal.
Root Cause: The failure was due to one of the dependent services.
Incident Timeline: 2 Hours & 4 minutes - 12/13, 08:50 UTC through 12/13, 10:54 UTC
We understand that customers rely on Application Insights as a critical service and apologize for any impact this incident caused.