Amazon Outage Cause Released

It appears as though the service outage Amazon AWS provided us with recently was the result of planned network infrastructure upgrades that weren’t executed properly. The result was a loss of connectivity between EBS nodes on both the primary and secondary networks concurrently exposing a design flaw that resulted in an onslaught of re-mirroring activity that saturated the infrastructure. Oops.

You can read more of the details here.