We've confirmed that all systems are back to normal with no customer impact as of 03/30, 17:00 UTC. Our logs show the incident started on 03/22, 10:00 UTC and that during the 8 days and 7 hours that it took to resolve the issue some of the customers who have tried to register their subscriptions to microsoft.insights would have experienced a message stuck in the registering state. If the problem is still being experienced re-registering from portal will fix the issue.
Root Cause: The failure was due to a deployment that happened for one of the backend services.
Incident Timeline: 8 Days & 7 Hours - 03/22, 10:00 UTC through 03/30, 17:00 UTC
We understand that customers rely on Application Insights as a critical service and apologize for any impact this incident caused.