On Sat, Jun 30, 2012 at 12:04 PM, Todd Underwood <toddunder@gmail.com>wrote:
This was not a cascading failure. It was a simple power outage
Cascading failures involve interdependencies among components.
Not always. Cascading failures can also occur when there is zero dependency between components. The simplest form of this is where one environment fails over to another, but the target environment is not capable of handling the additional load and then "fails" itself as a result (in some form or other, but frequently different to the mode of the original failure). Whilst the Amazon outage might have been a "simple" power outage, it's likely that at least some of the website outages caused were a combination of not just the direct Amazon outage, but also the flow-on effect of their redundancy attempting (but failing) to kick in - potentially making the problem worse than just the Amazon outage caused. Scott