We've confirmed that all systems are back to normal with no customer impact as of 11/05, 09:15 UTC. Our logs show the incident started on 11/05, 8:00 UTC and that during the 1 hour and 15 minutes that it took to resolve the issue. Customer using Azure Log Analytics, Log Search and/or Sentinel in West Central US who may have experienced intermittent query failures and delayed or missed alerts.
Root Cause: The failure was due to some instances of a backend service became unhealthy, causing the aforementioned delays and preventing requests from completing.
Incident Timeline: 1 Hour & 15 minutes - 11/05, 08:00 UTC through 11/05, 09:15 UTC
We understand that customers rely on Azure Log Analytics, Log Search and/or Sentinel as a critical service and apologize for any impact this incident caused.