From approximately 9:40 PM UTC until 10:40 PM UTC, Azure's global DNS service experienced a service availability issue caused by an anomalous surge in DNS queries from across the globe. Azure's edge DNS servers failed to handle the increased volume due to a code defect, and the result was that during this time many users were unable to reach the AchieveIt web application in both our Commercial and US Government environments. Azure has since resolve the defect in its DNS service to prevent a recurrence of the same type of service interruption.