We've confirmed that all systems are running as expected since issue has been mitigated. Our logs show the issue started on 05/02 19:30 UTC and ended by 05/15 01:08 UTC. During the duration of the issue up to 10% of alert notifications for Classic Alerts for Application Insights customers might not have delivered. We understand the issue completely and additional steps have been taken to assure that we do not see similar occurrence in future.
Root Cause: The root cause has been isolated to a single service instance which was not serving the traffic as expected.
Incident Timeline: 05/02 19:30 UTC through 05/15 01:08 UTC
We understand that customers rely on Application Insights as a critical service and apologize for any impact this incident caused.
Initial Update: Wednesday, 15 May 2019 00:01 UTC
We are aware of issues within Application Insights and are actively investigating. Some customers may experience issues with notifications not being delivered.
We are working hard to resolve this issue and apologize for any inconvenience.