I’m a tech expert. This is the likely cause of the global Microsoft outage - The Independent

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Microsoft has suffered a major global outage, bringing many of its widely used tools, including email and cloud storage, to a standstill.

According to outage tracking site DownDetector, some 130,000 people reported issues accessing Microsoft Outlook as of early Thursday afternoon US Eastern time (early Friday morning in Sydney). In a statement on X, the tech giant said it was “aggressively pursuing all pathways to reduce impact” and “restarting affected servers to return them to service”.

In an article for The Conversation last month, I explained how the whole internet is unlikely to go down but several services can become unavailable together when they rely on shared systems.

This outage shows precisely what happens when that shared infrastructure fails – and why we must prepare for digital outages in a similar way we do for natural disasters.

The list of services Microsoft says are “potentially impacted” by the outage is long. It includes services used for email, document sharing, meetings and managing tasks, such as Outlook, Microsoft Teams, SharePoint Online, Microsoft Copilot 365, Microsoft Planner and Microsoft Exchange Online. It also includes Microsoft Defender, a cloud-based cybersecurity service.

With so many digital services affected, the real-world impacts of the outage have been widespread, and go far beyond missed emails or workplace meetings.

For example, family violence workers reportedly can’t access databases which contain client details. Schools can’t provide online lessons for remote students. Psychologists can’t provide telehealth consultations. Businesses are unable to process orders. Job hunters are unable to make it to planned interviews. Some government service centres have been forced to closed.

The disruption also reached services outside Microsoft. OpenAI and Anthropic reported problems with the tools that connect their artificial intelligence (AI) services to Microsoft 365.

This shows how a problem in one part of the digital world can affect tools that appear separate, and even services provided by other companies.

The outage comes after other disruptions to Microsoft services earlier this year. For example, in January, Outlook, Teams and other Microsoft 365 services were down for hours. Then in August, Microsoft Outlook and Exchange Online were disrupted by a code update which took several days to fix.

As of early Friday afternoon Sydney time, Microsoft has not yet named a root cause of the outage, and its account of the failure has shifted since it was first reported.

Initially the company said elevated load across multiple regions was reported first. It then clarified the load was not driven by an increase in traffic, but a large number of servers becoming unexpectedly unavailable.

Attention then moved to the automated “health checks” Microsoft uses to judge whether a server is fit to carry traffic, and to the component that processes them.

The company described a core process on the affected servers as becoming “overwhelmed”. Software deployments and configuration changes were paused while recent changes were reviewed, although none was found to correlate with the start of the disruption.

The evidence does not suggest a cyberattack.

Mahmoud Elkhodr is a Senior Lecturer in Information and Communication Technologies at CQUniversity Australia.

This article is republished from The Conversation under a Creative Commons licence. Read the original article.