2016/11/22 10:01:01 [error] 18314#0: *1 connect() failed (111: Connection refused) while connecting to upstream, client:XX.XX.X.XXX, server: www.domain.com, request: "GET / HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "www.domain.com"

Lets edit /etc/php-fpm.d/www.conf and uncomment the line of 127.0.0.1:9000 and comment listen = /var/run/php-fpm/php-fpm.sock.

; Note: This value is mandatory.
listen = 127.0.0.1:9000
#listen = /var/run/php-fpm/php-fpm.sock

And restart PHP-FPM & nginx

/bin/systemctl restart  php-fpm.service

/bin/systemctl restart  nginx.service