Observability is a characteristic of an application that refers to how well a system’s state or status can be understood from its external outputs. Computer systems are measured by observing CPU time, memory, disk space, latency, errors, etc. The more observable a system is, the easier it is to understand how it’s doing by looking at it.

The observability of a system has a significant impact on its operating cost. Observable systems yield meaningful, actionable data to their operators, allowing them to achieve favorable outcomes and less downtime. Note that more information does not necessarily translate into a more observable system. In fact, sometimes the amount of information generated by a system can make it harder to identify valuable health signals from the noise generated by the application. Observability requires the right data to make the right decisions.