Amazon has published a post-event summary to shed some light on the root cause behind this week’s massive AWS outage that took down a long list of high-profile sites and online services, including Ring, Netflix, Amazon Prime Video, and Roku.
The outage started at roughly 10:30 AM EST on Tuesday. It affected the US-EAST-1 AWS region, which ensures connectivity for people and companies in the northeastern part of the United States.
As a result, streaming through Netflix, Amazon Prime, and Roku was immediately impacted together with Ring devices, brought down and unreachable, according to users reporting that they couldn’t connect to their cameras.
Around the same time, Amazon delivery employees began sharing on Reddit that they could no longer access internal apps required to scan packages, access delivery routes, or see upcoming schedules.
“At 7:30 AM PST, an automated activity to scale capacity of one of the AWS services hosted in the main AWS network triggered an unexpected behavior from a large number of clients inside the internal network,” Amazon explained in a summary of this incident.
“This resulted in a large surge of connection activity that overwhelmed the networking devices between the internal network and the main AWS network, resulting in delays for communication between these networks.