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Internal logger

Klogging has an internal logger that emits string messages to the console.


The core function log(String, Level, String, Exception?) is called by utility functions for five levels:

  • trace("Sink", "Forwarding event ${} to sink $name")

  • debug("Emitter", "Starting events channel")

  • info("Configuration", "Setting configuration using the DSL with append=$append")

  • warn("JsonConfiguration", "Exception parsing JSON", ex)

  • error("Sink", "A serious error has occurred", ex)


Message templates are not currently supported by the internal logger.

Minimum logging level

The internal logger has a minimum level from which it will emit log messages, set by the ‘global’ variable kloggingMinLogLevel.

Under the hood

The code constructs log events, renders them as string messages using a specific renderer and sends them to the console.

  • If the logging level is INFO or lower, they are sent to the standard output stream.
  • If the logging level is WARN or higher, they are sent to the standard error stream. Some shells will show these messages in a different colour (e.g. red).