Understanding observability
The concept of observability was originally introduced as part of control theory, which deals with the control of self-regulated dynamic systems. Control theory is an abstract concept and has interdisciplinary applications; it basically provides a model governing the application of system inputs to drive a system to a desired state while maximizing its stability and performance.
Figure 7.1 – Observability in control theory
The observability of a system is a measure of how well we can understand the internal state of that system, based on the signals and observation of its external outputs. It is then used by controllers to apply compensating control to the system to drive it to the desired state. A system is considered observable if it emits signals, which the controller can use to determine the system’s status.
In the world of IT, systems are software systems, and controllers are operators who are other software...