Debug with Tomcat
From OpenKM Documentation
You can debug your OpenKM installation using the Tomcat logging facility. This is an useful thing when you have problems with your configuration. Default OpenKM installation tries to log important events like errors and warnings. Is possible to change this configuration editing the file $TOMCAT_HOME/conf/logging.properties.
Default Tomcat log configuration can generate a lot of messages. These files are stored at $TOMCAT_HOME/logs.