We've confirmed that all systems are back to normal with no customer impact as of 10/22, 08:30 UTC. Our logs show the incident started on 10/22, 01:30 UTC and that during the 7 hours that it took to resolve the issue some customers may have experienced failure notifications when accessing or performing service management operations for Azure Activity Log Alert Rules.
Root Cause: The failure was due to issues with one of our dependent services.
Incident Timeline: 7 Hours - 10/22, 01:30 UTC through 10/22, 08:30 UTC
We understand that customers rely on Activity Log Alerts as a critical service and apologize for any impact this incident caused.