We've confirmed that all systems are back to normal with no customer impact as of 12/17, 14:00 UTC. Our logs show the incident started on 12/17, 05:20 UTC and that during the 8 hours & 40 minutes that it took to resolve the issue some customers using Azure Monitor and/or Sentinel may have experienced ingestion latency and data gaps and incorrect alert activation in Germany West Central region.
Root Cause: The failure was due to one of our dependent service, caused backend instances to become unhealthy.
Incident Timeline: 8 Hours & 40 minutes - 12/17, 5:20 UTC through 12/17, 14:00 UTC.
We understand that customers rely on Azure Monitor as a critical service and apologize for any impact this incident caused.
Initial Update: Thursday, 17 December 2021 07:25 UTC
We are aware of issues within Azure Monitor and are actively investigating. Some customers using Azure Monitor may experience ingestion latency and data gaps and incorrect alert activation in Germany West Central regions.
Work Around: None
Next Update: Before 12/17 10:30 UTC
We are working hard to resolve this issue and apologize for any inconvenience. -Anmol