Overview
On October 4, 2021, Facebook and its platforms — Instagram, WhatsApp, and Messenger — suffered a global outage that lasted approximately six hours. The outage was caused by a faulty configuration change in the backbone routers responsible for coordinating network traffic between Facebook’s data centers.
Technical Details
The root cause of the outage was a BGP (Border Gateway Protocol) configuration error. When the BGP routes were withdrawn, Facebook’s internal systems were cut off from the internet, including its DNS servers, which rendered its services unreachable. The interconnected nature of the systems resulted in cascading failures across all its platforms.
Impact
- User Disruption: Billions of users worldwide were unable to access Facebook, Instagram, and WhatsApp.
- Business Impact: Businesses that rely on these platforms for sales and communication were critically affected, resulting in an estimated loss of millions of dollars in revenue.
- Technical Community Response: The event showcased the critical role of BGP in internet routing and how a misconfiguration can lead to widespread outages.
Lessons Learned
This outage underscored the risks of centralized infrastructure and the need for redundancy. It serves as a wake-up call for companies to decentralize critical services and ensure system resilience in the event of failures.
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