AWS outage, 20 October 2025

AWS us-east-1 DynamoDB DNS outage (20 October 2025). The disruption lasted about 14 hours 32 minutes, according to AWS’s own timeline.

What happened. A latent race condition between two DNS Enactors in DynamoDB’s automated DNS management system let a stale plan overwrite a newer one, and cleanup then deleted it. That left an empty DNS record for dynamodb.us-east-1.amazonaws.com, which automation could not repair; EC2 launches and NLB health checks then failed in follow-on stages.

What changes. AWS disabled DynamoDB DNS Planner/Enactor automation worldwide pending a race-condition fix, and is adding NLB velocity controls and new EC2 recovery tests and throttling.

Questions

What caused the AWS outage in October 2025?

A latent race condition between two DNS Enactors in DynamoDB’s automated DNS management system let a stale plan overwrite a newer one, and cleanup then deleted it.

Which services were affected?

DynamoDB, EC2 instance launches, Network Load Balancer, and AWS services depending on DynamoDB.

Read how shared dependencies spread a failure in why one cloud outage can break unrelated apps, or browse the outage archive.