We've confirmed that all systems are back to normal with no customer impact as of 05/05, 06:00 UTC. Our logs show the incident started on 05/05, 04:00 UTC and that during the 2 hours that it took to resolve the issue some of the customers in South Central US and East US experienced failure in Proactive Detection.
Root Cause: The failure was due to the issues in one of our dependent services.
Incident Timeline: 2 Hours - 05/05, 04:00 UTC through 05/05, 06:00 UTC
We understand that customers rely on Application Insights as a critical service and apologize for any impact this incident caused.