Common Used Command // check module status httpd -M // test apache config apachectl configtest // restart apache service sudo apachectl restart sudo apachectl graceful Troubleshooting // make sure there is no program occupid the 80 port sudo lsof -i :80 | egrep "PID|LISTEN" Common Used File and Directory // startup script /System/Library/LaunchDaemons/org.apache.httpd.plist // default configration /etc/apache2/httpd.conf // user sites /etc/apache2/users/jay.lin.conf Proxy Setting https://www.digitalocean.com/community/tutorials/how-to-use-apache-as-a-reverse-proxy-with-mod_proxy-on-centos-7