Reasons for october 4th outage #facebook

To all the people and businesses around the world who depend on us, we are sorry for the inconvenience caused by today’s outage across our platforms. We’ve been working as hard as we can to restore access, and our systems are now back up and running. The underlying cause of this outage also impacted many of the internal tools and systems we use in our day-to-day operations, complicating our attempts to quickly diagnose and resolve the problem.

Our engineering teams have learned that configuration changes on the backbone routers that coordinate network traffic between our data centers caused issues that interrupted this communication. This disruption to network traffic had a cascading effect on the way our data centers communicate, bringing our services to a halt.

Our services are now back online and we’re actively working to fully return them to regular operations. We want to make clear that there was no malicious activity behind this outage — its root cause was a faulty configuration change on our end. We also have no evidence that user data was compromised as a result of this downtime. (Updated on Oct. 5, 2021, to reflect the latest information)

People and businesses around the world rely on us every day to stay connected. We understand the impact that outages like these have on people’s lives, as well as our responsibility to keep people informed about disruptions to our services. We apologize to all those affected, and we’re working to understand more about what happened today so we can continue to make our infrastructure more resilient.