Observability for Beginners: Logs, Metrics, Traces, and Everything Around Them

A running service generates events constantly.

Requests arrive, functions run, errors appear, and each one is a thing that happened at a specific time with a specific context and a specific outcome.

Logs, metrics, and traces are three ways of looking at this same stream. A log captures one event as a line of text, a metric counts or aggregates many events, and a trace links related events as they move across services. Most of the concepts in observability, including cardinality, sampling, and correlation, are consequences of this structure.

In this article, we will look at the basics of observability in detail with concepts like logs, metrics, and traces explained in detail.