If you want to disable http access logs in WSO2 products then go to catalina-server.xml which is located {CARBON_HOME}/repository/conf/tomcat directory, and remove the following property
<Valve className="org.apache.catalina.valves.AccessLogValve" directory="${carbon.home}/repository/logs"
prefix="http_access_" suffix=".log"
pattern="combined" />
Please refer this for more details