[Increased Error Rates] Service impact: Increased Error Rates

Between 3:49 PM and 5:06 PM PDT, we experienced increased error rates affecting new instance launches in the US-EAST-1 Region. During this time, customers may have experienced elevated error rates when attempting to launch new EC2 instances through RunInstances, CreateFleet, and related EC2 launch workflows. AWS services that launch EC2 instances on behalf of customers, including Amazon ECS, AWS Fargate, Amazon EMR, amongst others were also impacted during this period. We identified the root cause as a recent deployment to a subsystem within the EC2 service responsible for processing instance launch requests. We initiated a rollback of the problematic deployment and began observing initial signs of recovery at 4:44 PM. Existing instances remain unaffected. The issue has been resolved and the service is operating normally.