Beginner’s Guide to Observability

Simply defined, observability is instrumenting systems and applications to collect metrics and logs. It’s building apps with the idea that someone is going to watch them. It comes from system control theory, the foundation of feedback systems, where observability is a measure of how well the internal states of a system can be inferred from knowledge of its external outputs1 — a kind of digital exhaust. Think of it as a property of a system — another attribute, like functionality, performance or testability.