If you are looking for a fast way for live monitoring your server http(s) traffics here's a tool that is easy to install : ngxtop
All you need is to have python and pip installed on your system :
apt-get install python python-pip
And then use
pip to install the tool
pip install ngxtop
If the installation fails, there is a big chance that you need to update the setup tools as well and try again :
pip install --upgrade setuptools pip install ngxtop
After the tool is installed you can type
ngxtop. The tool assumes you didn't modify the access log in your nginx configuration (/var/log/nginx/access.log) and run successfully.
Next you can visit one page of your server and you should see live update in the terminal.
More details on the github
If you search for a more advanced tool you should also consider checking goaccess.
goaccess is more like a log analyzer, it is also real-time but the stats is made from all the data in the log versus
ngxtop that starts making stats from the moment you run the command.