• http://nginx.org/

ln -s /etc/nginx/sites-available/aaa.example.com /etc/nginx/sites-enabled/aaa.example.com
ln -s /etc/nginx/sites-available/aaa.example.com /etc/nginx/sites-enabled/bbb.example.com

• Installing Nginx from Sources
• Installing NGINX package for Red Hat/CentOS

• Nginx : Default nginx.conf of CentOS7

You can set it to the same number cpu cores.

#grep processor /proc/cpuinfo | wc -l 
worker_processes 2;

It specifies the maximum number of connections that one of the worker process can be processed at the same time

#ulimit -n
events {
    worker_connections  1024;
}

http {
        server_tokens off;

    ##
    # Virtual Host Configs
    ##

    include /etc/nginx/conf.d/*.conf;
    include /etc/nginx/sites-enabled/*;

ln -s /etc/nginx/sites-available/aaa.example.com /etc/nginx/sites-enabled/aaa.example.com
ln -s /etc/nginx/sites-available/aaa.example.com /etc/nginx/sites-enabled/bbb.example.com

root   /usr/share/nginx/html;

server {
    server_name example.com;

}

server {
    server_name example.com www.example.com;
}

server {
    server_name *.example.com;

}

server {
    listen *:80 default_server;
    server_name example.com;
}

server {
    listen 443 ssl;

   (abbr)

    ssl on;
    ssl_certificate /etc/nginx/ssl/xxx.crt;
    ssl_certificate_key /etc/nginx/ssl/xxx.key;
    ssl_session_timeout 5m;
    ssl_ciphers 'AES128+EECDH:AES128+EDH:!aNULL';
    ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
    ssl_prefer_server_ciphers on;

   (abbr)
}

• Nginx Sample Configuration of php-fpm (Use TCP or Socket)
• Nginx Sample Configuration of DokuWiki
• Nginx Sample Configuration of Codeigniter
• Nginx Sample Configuration of Rewrite and return
• How to use CGI in NGINX