Security News > 2021 > December > Amazon explains the cause behind Tuesday’s massive AWS outage
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.
"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."
Our Support Contact Center also relies on the internal AWS network, so the ability to create support cases was impacted from 7:33 AM until 2:25 PM PST. We expect to release a new version of our Service Health Dashboard early next year that will make it easier to understand service impact and a new support system architecture that actively runs across multiple AWS regions to ensure we do not have delays in communicating with customers.
The Tuesday AWS outage is definitely not unique as it follows multiple other similar events since 2011, including a large-scale incident that affected the same region in November 2020.
One year prior, during September 2019, a power outage that hit the AWS US-EAST-1 data center in North Virginia caused data loss for all Amazon customers lacking working backups to restore their files.