I'm not sure I can agree.

> Are they using the formal definition of chaos, or just a colloquialism?

Is it a colloquialism to use a word in its normal English sense? Chaos as a word precedes Chaos Theory by some thousands of years. If I write a theory and take over an existing word in everyday use, it seems a bit much to accuse every one else of colloquiallism when they use an existing but less strict definition?

> If I write a theory and take over an existing word in everyday use, it seems a bit much to accuse every one else of colloquialism when they use an existing but less strict definition?

It does, but engineering is a technical profession and it's practitioners are likely familiar with the mathematical concept.

I've read about applications of chaos theory in system design, and I expected 'Principals of Chaos Engineering' to be about that topic.

The problem I have with the name is that it feels like their audience is people not familiar with the mathematical concept. In other words, not engineers; in other words, non-technical managers. And that marks it as the latest marketing fluff being pitched by management consultants.

People familiar with the mathematical concept will almost always be talking about something like "nonlinear dynamics" instead, anyway.

Funny you say that. I had to restrain myself from using that term. Technically, chaotic systems are only a subset of nonlinear systems. For example, solitons are nonlinear, but neither are they chaotic.

They are using a dictionary definition, I believe. It is “Engineering of Chaos”, which is to describe how computer systems, especially when distributed, can have near random failure states, resulting in what appears to be a chaotic system. Network partitioning, hard drives failing, bits randomly flipping because of physics would all be examples of such failure states.

The engineering comes in when we try to simulate such situations and create processes for hardening applications against those types of failure.

It has nothing to do with chaos theory.

They’re just trying to co-opt “chaos” as a buzzword for fault-tolerant systems.

Yes. The chaos part is where management fails to appreciate the time and resources to make things fault-tolerant. :)

I agree. The article is not clear and I think it uses the term “chaos” where the word “error” might be better suited.

In this context, "chaos" means roughly "injecting failures/latency"

Resilient Engineering, then, would be a less buzz-wordy alternative that expresses what they mean.

I would call that "noise" rather than chaos.