Error log: upstream timed out (110: Connection timed out) on Nginx

Question

Hello, I use Nginx on Ubuntu 14.04

And my php script is just loading and won’t open! After a long time just loading the page, I come across this message:

---

An error occurred.

Sorry, the page you are looking for is currently unavailable.
Please try again later.

If you are the system administrator of this resource then you should check the error log for details.

Faithfully yours, nginx.

---

I went to see the.log error on that way:

/var/log/Nginx/nginx_error.log

and show me the following message:

---

[error] 2019#0: *1 upstream timed out (110: Connection timed out) 
    while reading response header from upstream, 
    client: x.x.x.x, server: localhost, request: "GET /sistema-10-reais/ HTTP/1.1", 
    upstream: "fastcgi://unix:/var/run/php5-fpm.sock", 
    host: "x.x.x.x.x"
root@meusistema:/var/log/nginx#

---

Where is x.x.x.x is my IP.