Major Microsoft 365 blackout raises tough questions for software giant

A “physical fiber networking event” has caused a major outage to Microsoft 365 – including its Office software – that has raised concerns among cloud users.

According to the company’s “Preliminary Post Incident Report (opens in new tab),” the outage lasted around 45 minutes between the hours of 11:05 AM and 11:50 AM UTC. The report reads: “This may have affected any user in Southern India trying to connect to Microsoft 365 services if they used a specific ISP provider.”

In an effort to reduce latency – and increase performance – Microsoft has been using its Edge computing architecture which involves local Edge data centers, many of which managed by ISP third-party partners. The affected Edge site, in Chennai, is one such example that is managed by a third party.

Microsoft 365 outage

The outage occurred when a “physical fiber networking event” meant that any requests routed to the Chennai Edge site were unable to communicate with the broader Microsoft network. The company suspects that there was a fiber cut which caused a loss in connection.

A tweet on the official Microsoft 365 Status account says: “We’re investigating an issue where users from the India region are unable to connect to some Microsoft 365 services. More details are available in your admin center under the SI MO400684.”

It seems similar problems were experienced elsewhere, with one user posting “Cannot log into Outlook and Teams in Uganda for the last 30 to 45 min,” and another reading “our side in malaysia under e3 not able to login since yesterday, has the issue resolved yet?”. Neither of which have been confirmed to be linked to this event.

In its reports, Microsoft details that it’s working with this specific third party to “build better resiliencies against this type of fiber event to stop this issue reoccurring.” It’s also “investigating [its] existing automated failover process,” and “reviewing options to optimize Edge site failovers to reduce potential impact times.” 

Nonetheless, an undisclosed number of Microsoft 365 users were left stranded as access to their productivity tools ground to a halt, which will have a lasting impact on the services in the Southern India region – and beyond.

Via The Register (opens in new tab)