Summary of the Amazon EC2 and Amazon RDS Service Disruption

"The issues affecting EC2 customers last week primarily involved a subset of the Amazon Elastic Block Store (“EBS”) volumes in a single Availability Zone within the US East Region that became unable to service read and write operations," Amazon says.

This caused instances trying to use these affected volumes to also get “stuck” when they attempted to read or write to them. In order to restore these volumes and stabilize the EBS cluster in that Availability Zone, Amazon disabled all control APIs (e.g. Create Volume, Attach Volume, Detach Volume, and Create Snapshot) for EBS in the affected Availability Zone for much of the duration of the event.

For two periods during the first day of the issue, the degraded EBS cluster affected the EBS APIs and caused high error rates and latencies for EBS calls to these APIs across the entire US East Region, Amazon says.

Summary of the Amazon EC2 and Amazon RDS Service Disruption