We've confirmed that all systems are back to normal with no customer impact as of 03/08, 06:10 UTC. Our logs show the incident started on 03/07, 12:10 UTC and that during the 6 hours that it took to resolve the issue all customers experienced might have experienced data issues Azure and OMS portal.
Root Cause: The failure was due to an issue with one of the internal service in Log analytics.
Incident Timeline: 6 Hours & 0 minutes - 03/07, 12:10 UTC through 03/08, 06:10 UTC
We understand that customers rely on Log analytics as a critical service and apologize for any impact this incident caused.
Update: Thursday, 08 March 2018 06:18 UTC
Root cause has been isolated to an issue related to an internal service in Log Analytics which was impacting multiple regions. To address this issue we have taken the necessary mitigation steps and subsequently we can see that the issue is resolved in all regions except for West Europe and South UK. Some customers in West Europe and South UK regions may experience data access issues and we estimate around 2 hours before the issue gets mitigated in all the regions.