We've confirmed that all systems are back to normal with no customer impact as of 04/25, 17:10 UTC. Our logs show the incident started on 04/22, 16:00 UTC and that during the 73 hours and 10 minutes that it took to resolve the issue some of the customers experienced loss of Application Insights logs and metrics and incorrect alert activation. Application Insights customers using some new SDK versions with deprecated instrumentation key based configuration were unable to ingest data into Application Insights. Customers using connection strings were unaffected.
Root Cause: We determined that a recent code change from a recent deployment was responsible for the issues mentioned above.
Incident Timeline: 73 Hours & 10 minutes - 04/22, 16:00 UTC through 04/25, 17:10 UTC
We understand that customers rely on Application Insights as a critical service and apologize for any impact this incident caused.