Prevent nginx 504 Gateway timeout using PHP set_time_limit()

Question

There are several ways in which you can set the timeout for php-fpm. In /etc/php5/fpm/pool.d/www.conf I added this line:

request_terminate_timeout = 180

Also, in /etc/nginx/sites-available/default I added the following line to the location block of the server in question:

fastcgi_read_timeout 180;

The entire location block looks like this:

location ~ \.php$ {
    fastcgi_pass unix:/var/run/php5-fpm.sock;
    fastcgi_index index.php;
    fastcgi_param   SCRIPT_FILENAME $document_root$fastcgi_script_name;
    fastcgi_read_timeout 180;
    include fastcgi_params;
} 

Now just restart php-fpm and nginx and there should be no more timeouts for requests taking less than 180 seconds.

Try this link, it has a better solution on how to fix this. So the steps are:

1. Open your nginx.conf file located in /etc/nginx directory.

2. Add this below piece of code under http { section:

   client_header_timeout 3000;
   client_body_timeout 3000;
   fastcgi_read_timeout 3000;
   client_max_body_size 32m;
   fastcgi_buffers 8 128k;
   fastcgi_buffer_size 128k;
   

   Note: If its already present , change the values according.

3. Reload Nginx and php5-fpm.

   $ service nginx reload
   $ service php5-fpm reload
   

   If the error persists, consider increasing the values.

You can't use PHP to prevent a timeout issued by nginx.

To configure nginx to allow more time see the proxy_read_timeout directive.

 sudo nano /etc/nginx/nginx.conf

Add these variables to nginx.conf file:

http {  
  # .....
  proxy_connect_timeout       600;
  proxy_send_timeout          600;
  proxy_read_timeout          600;
  send_timeout                600;
}

And then restart:

service nginx reload

The correct answer is increasing fastcgi_read_timeout in your Nginx configuration.
Simple as that!

There are three kinds of timeouts which can occur in such a case. It can be seen that each answer is focused on only one aspect of these possibilities. So, I thought to write it down so someone visiting here in future does not need to randomly check each answer and get success without knowing which worked.

1. Timeout the request from requester - Need to set timeout header ( see the header configuration in requesting library)
2. Timeout from nginx while making the request ( before forwarding to the proxied server) eg: Huge file being uploaded
3. Timeout after forwarding to the proxied server, server does not reply back nginx in time. eg: Time consuming scripts running at server

So the fixes for each issue are as follows.

1. set timeout header eg: in ajax

   $.ajax({
       url: "test.html",
       error: function(){
           // will fire when timeout is reached
       },
       success: function(){
           //do something
       },
       timeout: 3000 // sets timeout to 3 seconds
   });
   

2. nginx Client timeout

   http{
        #in seconds
       fastcgi_read_timeout 600;
       client_header_timeout 600;
       client_body_timeout 600;
    }
   

3. nginx proxied server timeout

   http{
     #Time to wait for the replying server
      proxy_read_timeout 600s;
   
   }
   

So use the one that you need. Maybe in some cases, you need all these configurations. I needed.