loggingLevel

Logginglevel is a configuration parameter used to control the verbosity of a logging system. It defines a threshold for which messages are emitted. Each log message is assigned a severity level, such as TRACE, DEBUG, INFO, WARN, ERROR, or FATAL. The logger maintains a current logginglevel, and a message is written only if its level is at or above the threshold, depending on the framework’s convention.

In many systems, the relation is that lower-severity messages are more verbose, while higher-severity messages indicate more important events. When the logginglevel is set to INFO, DEBUG and TRACE messages are filtered out, while INFO, WARN, ERROR, and FATAL are logged. Some frameworks also support NONE or OFF to disable logging completely.

Configuration can be done programmatically, via configuration files, or environment variables. It may be global for the application or per-logger or component. Dynamic adjustment at runtime is common in modern systems, enabling operators to raise the level to diagnose issues without restarting services.

Common levels include TRACE or DEBUG for development details; INFO for regular operation; WARN for unusual or unexpected events that do not indicate failure; ERROR for failed operations; FATAL for unrecoverable conditions.

Best practices include starting with a sensible default (often INFO or WARN), using consistent naming, preferring per-component levels, and avoiding exposing sensitive information at lower levels in production. Consider using lazy evaluation of log messages to avoid unnecessary computation when the level is filtered. Caveats include potential performance impact from high log volume and the need to ensure thread-safe loggers and appropriate access to level settings.