Observability
可观测性（observability） 是一种系统设计目标，让系统可以被观测，让不熟悉的人也能发现系统问题。最重要的是，可观测系统能够辅助我们发现、解决新问题，也就是我们不知的未知（Unknown unknowns）。
Unknown unknowns
“…there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns — the ones we don’t know we don’t know.”[1]
- Donald Rumsfeld
一种目前广泛采用的 可观测性 标准是 OpenTelemetry。
Observability Primer
Observability lets us understand a system from the outside, by letting us ask questions about that system without knowing its inner workings. Furthermore, it allows us to easily troubleshoot and handle novel problems (i.e. “unknown unknowns”), and helps us answer the question, “Why is this happening?”[2]