AWS outage, 13 June 2023

AWS Lambda us-east-1 cell scaling outage (13 June 2023). The disruption lasted about 3 hours 48 minutes, according to AWS’s own timeline.

What happened. While scaling up for normal daily traffic, the Lambda Frontend fleet in one cell crossed a capacity threshold never reached before. This triggered a latent software defect: execution environments were allocated but never used, so invocations failed and other services that depend on Lambda degraded.

What changes. AWS disabled the triggering scaling, fixed the bug in all regions, and is bounding all Lambda cells to a well-tested size.

Questions

What caused the AWS outage in June 2023?

While scaling up for normal daily traffic, the Lambda Frontend fleet in one cell crossed a capacity threshold never reached before.

Which services were affected?

AWS Lambda, STS, AWS Management Console, EKS, Amazon Connect, EventBridge, AWS Sign-in (SAML).

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