Major Microsoft outage: “Widespread recovery and stabilization have been observed”

U.S.-based Microsoft announced a major outage affecting its cloud services for businesses on the 12th, U.S. time. Issues including the inability to send email occurred around the world, and the scope of the impact was expected to expand. On the 13th, Japan time, reports of recovery from many users came in one after another, and by the morning of the 14th, it was indicated that widespread recovery and stabilization had been observed.

The outage is attributed to multiple servers unexpectedly becoming unavailable, concentrating the load on the remaining servers. Multiple health-check failures occurred, and the problem may have expanded as overall communications became unevenly distributed. No physical damage has been confirmed at this time.

Recovery efforts are proceeding through measures including restarting the affected servers and eliminating the concentration of traffic on specific servers. Microsoft ruled out the possibility of a cyberattack and indicated that it would continue its investigation and work to publish a detailed report.

In the United States, issues with email and calendar functions have been reported at government agencies and universities, among other organizations, and numerous reports of Outlook problems have emerged around the world. In Japan, some users have been confirmed to have been unable to access email since the morning of the 13th, raising concerns about the impact on business operations.