Log files are written by the Tomcat valve AccessLogValve. A valve, Tomcat only, is a Java class that preprocesses access requests. You can associate valves in server.xml to the containers engine, host and context.
Search TOMCAT_HOME/conf/server.xml for “AccessLogValve”. Specify the attribute directory as shown in this example:
<Valve className="org.apache.catalina.valves.AccessLogValve" directory="c:\tomcat\logs" prefix="localhost_access_log." suffix=".txt" pattern="common"/>
This will cause all the access logs of the hosting container to be written to c:\tomcat\logs.