We've confirmed that all systems are back to normal with no customer impact as of 3/25, 11:45 UTC. Our logs show the incident started on 3/35, 10:15 UTC and that during ~2 hours duration of incident that it took to resolve the issue some customers in East US experienced misfiring alerts.
Root Cause: None
Incident Timeline:1 Hour & 30 minutes - 3/25, 10:15 UTC through 3/25, 11:45 UTC
We understand that customers rely on Application Insights as a critical service and apologize for any impact this incident caused.
Initial Update: Monday, 25 March 2019 23:10 UTC
We are aware of issues within Application Insights and are actively investigating. Some customers may experience Alerting failure.
Work Around: none
Next Update: Before 03/26 01:30 UTC
We are working hard to resolve this issue and apologize for any inconvenience. -Anupama