We've confirmed that all systems are back to normal for Log Search Alerts, Application Insights and Azure Log Analytics in South Central US with no customer impact as of 1/18, 22:35 UTC. Our logs show the incident started on 1/18, 19:10 UTC and that during the 3 hours, 25 minutes that it took to resolve the issue 22% of customers experienced query failures or timeouts as well as possible misfired alerts or expected alerts not firing.
Root Cause: The failure was due to a maintenance process exceeding expected timelines.
Incident Timeline: 3 hours ,25 minutes - 1/18, 19:10 UTC through 1/18, 22:35 UTC
We understand that customers rely on Azure Log Analytics as a critical service and apologize for any impact this incident caused.
Initial Update: Saturday, 18 January 2020 19:41 UTC
We are aware of issues within Application Insights and Log Analytics in South Central US region and are actively investigating. Some customers may experience delayed ingestion, failures or timeouts for queries, and misfired or not fired expected alerts.
Work Around: None
Next Update: Before 01/18 22:00 UTC
We are working hard to resolve this issue and apologize for any inconvenience. -Jeff