Development-oriented logging configuration

Our docs are on GitHub, and all contributions are welcome. Suggest an edit or report a problem.

A complete logging environment for dev.

Log output

Log messages at WARN or ERROR will be printed to STDOUT. All application log messages will go to log/app.log. All log messages will go to log/all.log.

Your application log messages are detected by looking at, which will look like

Log messages are limited to a maximum size of 512MB for each file (for a total of 1GB), when this happens the oldest files are deleted. Logs older than 15 days are deleted automatically.

Log input

Logs are collected from

  • SLF4J

  • Log4j 1

  • Log4j 2

  • Commons Logging

  • OSGI LogService

  • java.util.logging (only when used in conjunction with dev-extras from


Make sure your production logback.xml is not activated at the same time as this library (usually the :dev alias). This will commonly happen if you place your logback.xml in src or resources. You should instead create a prod folder for production-only assets like your production logback.xml.


This would not have been possible without Stuart Sierra’s foundation in

Last updated 2019-06-06 18:48:45 +0100