We've confirmed that all systems are back to normal with no customer impact as of 04/28, 16:30 UTC. Our logs show the incident started on 04/27, 19:30 UTC and that during the 21 hours that it took to resolve the issue all the customers who are receiving custom logs, network monitoring logs, onprem IIS logs may have experienced delay on ingesting the data into customer workspaces.
Root Cause: The failure was due to an issue in one of our dependent services.
Incident Timeline: 21 Hours - 04/27, 19:30 UTC through 04/28, 16:30 UTC
We understand that customers rely on Azure Log Analytics as a critical service and apologize for any impact this incident caused.