Re: FYI Netflix is down

[Scott Howard <scott () doc net au>]

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