: the troubles comes when you integrate third-party stuff depending on : log4j (as I currently do). Having said this you have a strong point when : looking at http://www.qos.ch/logging/classloader.jsp
there have been several discussions baout changing the logger used by Solr ... the best summation i can give to these discussions is: * JDK logging is universal * using any other logging framework would add a dependency without adding functionality * there are too many differnet frameworks, each with their own pros/cons supporters/objectors that switching to any of them would be an uphill social battle as well as an code effort expenditure. * as a webapp, Solr runs ina Servlet Container - any third party logging framework we may pick to use could have bad interaction with some Servlet Containers (ie: classloader issues, etc...) but all servlet containers must be able to handle JDK logging. Some reading that should be considered mandatory before any futher discussion... http://www.nabble.com/logging---slf4j--tf3366438.html#a9366144 http://www.nabble.com/Changing-Logging-in-Solr-to-Apache-Commons-Logging-tf3484843.html#a9782039 Specificly with regard to commons-logging, note the last paragraph of this URL... http://wiki.apache.org/jakarta-commons/Commons_Logging_FUD "...In fact, there are very limited circumstances in which Commons Logging is useful. If you're building a stand-alone application, don't use commons-logging. ..." -Hoss