This article is contributed. See the original author and article here.

Final Update: Tuesday, 18 May 2021 20:15 UTC

We’ve confirmed that all systems are back to normal with no customer impact as of 05/18, 16:00 UTC. Our logs show the incident started on 05/18, 12:00 UTC and that during the 4 hours that it took to resolve the issue customers using Log Analytics in UK South  may have experienced intermittent data latency and incorrect alert activation for resources in this region.
  • Root Cause: After our investigation, we found that a backend scale unit become unhealthy due to an ingestion error. This ingestion is to process logging data for Log Analytics and caused alert systems to fail.
  • Incident Timeline: 4 Hours  – 05/18, 12:00  UTC through 05/18, 16:00 UTC
We understand that customers rely on Azure Log Analytics as a critical service and apologize for any impact this incident caused.

-Vincent

Brought to you by Dr. Ware, Microsoft Office 365 Silver Partner, Charleston SC.