PHP timeouts not being logged

Applicable to:

• Plesk Onyx for Linux

Symptoms

• A domain in Plesk configured with Apache + with Proxy Nginx + PHP-FPM
• nginx error 504 is shown when the PHP script exceeds configured timeout
• PHP error log file does not contain a corresponding entry regarding script execution timeout

Cause

nginx proxy_read_timeout has the same value as PHP max_execution_time, as a result the connection being terminated before PHP has any time to log any PHP error.

Nginx proxy_read_timeout directive limits the only interval between successive reads and operates with real (clock) time.
PHP max_execution_time is about time consumed by the CPU, details here. PHP process can spend a lot of time waiting for database response or response from a query to some external service.

Workaround

Increase proxy_read_timeout by creating a custom hosting confiuration template:

1. Connect to the server via SSH

2. Copy the required template from default/ to custom/ preserving the directory structure:

   # mkdir -p /usr/local/psa/admin/conf/templates/custom/domain
   # cp /usr/local/psa/admin/conf/templates/default/domain/nginxDomainVirtualHost.php /usr/local/psa/admin/conf/templates/custom/domain/nginxDomainVirtualHost.php

3. Modify the templates as follows by adding +20 seconds to the predefined timeout:

   # proxy_read_timeout <?php echo min($VAR->domain->physicalHosting->scriptTimeout, 2147483) + 20 ?>;

4. Check that the modified template is a valid PHP files:

   # plesk php -l /usr/local/psa/admin/conf/templates/custom/domain/nginxDomainVirtualHost.php

5. Generate new configuration files:

   • For the particular domain:

     # plesk sbin httpdmng --reconfigure-domain example.com

   • For all domains:

     # plesk sbin httpdmng --reconfigure-all