We've confirmed that all systems are back to normal as of 03/07, 22:00 UTC. Our logs show the incident started on 03/05, 18:00 UTC and during that timeline, customers in West US region may have missed results intermittently from Web tests that ran.
Root Cause: The failure was due to client side connections not getting reset when endpoint configurations changed.
Lessons Learned: Connection persistency between services needs to be evaluated and fixed.
Incident Timeline: 03/05, 18:00 UTC through 03/07, 22:00 UTC
We understand that customers rely on Application Insights as a critical service and apologize for any impact this incident caused.