Once Nginx web server is up and running in a production environment, you will want to monitor its activity in real time. In fact, general network monitoring software such as Nagios, Zabbix, Munin provide support for real-time Nginx monitoring. However, if you do not need comprehensive reporting capabilities or long-term statistics offered by such tools, but instead, just want a quick and easy way to monitor the requests coming to an Nginx web server, I would recommend a command line tool called ngxtop.