In my opinion, it doesn't count unless its in production.
Why? Your customers use your production environment, not your test environment. Something will cause loss of an instance for you:
* Mistaken termination
* AWS retirement (and you missed the email)
* Cable trip in the data center
* <Something else we can come up with>
* <This list goes on>
So, vaccinate against the loss of an instance cratering your service. Give your prod environment a booster shot (with Chaos Monkey or something like it) every hour of every day. Then, when anything from the above list happens you're infrastructure handles it gracefully and without intervention. Continued booster shots ensure that this stability continues through config changes, software version changes, OS changes, tooling changes, etc.
I think the better question is "Why wouldn't you do this?"
Why? Your customers use your production environment, not your test environment. Something will cause loss of an instance for you: * Mistaken termination * AWS retirement (and you missed the email) * Cable trip in the data center * <Something else we can come up with> * <This list goes on>
So, vaccinate against the loss of an instance cratering your service. Give your prod environment a booster shot (with Chaos Monkey or something like it) every hour of every day. Then, when anything from the above list happens you're infrastructure handles it gracefully and without intervention. Continued booster shots ensure that this stability continues through config changes, software version changes, OS changes, tooling changes, etc.
I think the better question is "Why wouldn't you do this?"