We've confirmed that all systems are back to normal with no customer impact as of 04/01, 02:30 UTC. Our logs show the incident started on 03/31, 23:00 UTC and that during the 3 hours and 30 minutes that it took to resolve the issue some customers using Azure metric alerts may not have received or experienced delays in receiving some metric alerts and additionally some alerts would have misfired.
Root Cause: The failure was due to issues with one of the backend services.
Incident Timeline: 3 Hours & 30 minutes - 03/31, 23:00 UTC through 04/01, 02:30 UTC
We understand that customers rely on Metric Alerts as a critical service and apologize for any impact this incident caused.