You need to optimize some PHP settings in order to be  able to upload larger size files, have more connections at the same time, etc. , including:

• Increase PHP execution time (PHP param max_execution_time is 30 seconds by default)
• Increase Max Upload Size 

In this tutorial, I will guide you to how to update on both Nginx and Apache server.

Nginx server

Changes in php.ini

On CentOS: php.ini is saved in: /etc/php.ini

On Ubuntu: php.ini is saved in: /etc/php/7.0/fpm/php.ini (which 7.0 is php version that installed in your server)

max_execution_time = 3000

(Increase php execution time to 3000 seconds)

Changes in Nginx Config

On file nginx config for your site, add this line fastcgi_read_timeout 3000; like this:

location ~ \.php$ {
                try_files $uri =404;
                fastcgi_split_path_info ^(.+\.php)(/.+)$;
                fastcgi_pass 127.0.0.1:9000;
                fastcgi_index index.php;
                fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
                include fastcgi_params;
                fastcgi_read_timeout 3000;
        }

(Increase request time out to 3000 seconds). Just add this line fastcgi_read_timeout 3000; keep default other configurations. You can preference this tutorial Install phpFox on nginx server for more detail

By Default, the path of nginx config is saved in /etc/nginx/nginx.conf (CentOS) or /etc/nginx/sites-available/default (Ubuntu)

Reload nginx and php

Run these commands:

systemctl restart nginx
 
#CentOS
systemctl restart php-fpm
 
#Ubuntu (which 7.0 is php version)
systemctl restart php7.0-fpm

Check your result

Check on phpinfo

Apache Server

Changes in php.ini

On CentOS: php.ini is saved in: /etc/php.ini

On Ubuntu: php.ini is saved in: /etc/php/7.0/apache2/php.ini (which 7.0 is php version that installed in your server)

max_execution_time = 3000

Reload apache

Run these commands:

#CentOS
systemctl restart httpd
 
#Ubuntu
systemctl restart apache2