We've confirmed that all systems are back to normal with no customer impact as of 01/17, 11:00 UTC. Our logs show the incident started on 01/17, 10:00 UTC and that during the 1 hour that it took to resolve some of customers may experience missing of misfired alerts when using Azure Metric Alert Rules.
Root Cause: The failure was due to a recent deployment task .
Incident Timeline: 1 Hour - 01/17, 10:00 UTC through 01/17, 11:00 UTC
We understand that customers rely on Alerts as a critical service and apologize for any impact this incident caused.