例如PHP负载均衡不需要反向代理，直接fastcgi_pass到多个php-fpm也可以做负载均衡。

具体配置：

upstream myapp {
    server 192.168.20.1:9000; # PHP-FPM 1
    server 192.168.20.2:9000; # PHP-FPM 2
    ......
}
server {
    listen 80;
    location ~ \.php$ {
        include fastcgi_params;
        fastcgi_param SCRIPT_FILENAME /phpfiles$fastcgi_script_name;
        fastcgi_pass myapp;
    }
}