On July 30, 2012, Netflix open sourced the Simian Army, which includes the now world famous Chaos Monkey. That was 3 years ago. For those not familiar, Chaos Monkey is a little service that runs in the background and goes around killing EC2 instances. Yes, that's right:

Chaos Monkey terminates live servers with real users in production.

The question is...

Why is this scary?

Why would I, running a mission critical system, not want to be continuously testing the resiliency of my service? Why would I want to be woken up in the middle of the night by PagerDuty just …

The term "blue/green deployment" is so misunderstood, we can't even decide on what to call it. Netflix call it Red/Black Deployment, while others call it A/B Deployment. Personally, I don't even know which color represents which thing, but this is only the beginning of the confusion.

So, I thought it might help to get some thoughts out there, have others weigh in, and see if we can't reach some consensus. After all, it's been 5 years since the oracle spoke. :-)

Here goes...

First off, blue/green deployment is the process of having 2 sets of machines, and …

What is cheaper than a reserved instance on AWS? How about not running an instance in the first place?

AWS announced a new reserved instance model, designed to save you up to 63% per instance. Most small and mid-sized companies aren’t going to commit for 3 years, so we are looking at something closer to 40% savings. That’s a good start.

However, chances are you are over provisioning - running more and/or larger EC2 instances than you actually need. Let me illustrate this with a few charts. Suppose the traffic to your site follows the usual wave.