Log

Definition

A log is traditionally one line of text output from an application, written to satisfy auditing or debugging requirements. Logs are unstructured when they are free-form text and structured when they adhere to a schema with well-defined fields (such as JSON). Log management solutions process large volumes of structured and unstructured logs and provide search and alerting capabilities.

In depth

Structured logging dramatically improves searchability: instead of parsing free-form strings with regex, engineers query specific fields like `service.name`, `http.status_code`, or `trace_id`. Log levels (DEBUG, INFO, WARN, ERROR) allow filtering by severity. In modern distributed systems, logs are one of three core telemetry signals alongside metrics and traces. Correlating logs with trace IDs allows engineers to jump from a failing trace span directly to the exact log lines emitted during that operation. obseria.io's log management supports both structured and unstructured logs at any ingestion rate, with full-text search and correlation to traces and metrics.

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