Solr 1.4 logging is based on the “SLF4J” API. To configure Solr to use Log4J as standard logging implementation deploy the Solr web application to your Tomcat. Once the Solr web application got started add the libraries “slf4j-log4j12-1.5.5.jar” and “log4j-1.2.15.jar” to $CATALINA_HOME/webapps/solr/WEB-INF/lib. Delete the library “slf4j-jdk14-1.5.5.jar” from $CATALINA_HOME/webapps/solr/WEB-INF/lib

