Failed to start PHP-FPM service: failed to open error_log

Symptoms

• Websites shows 503 Service Unavailable.

• Domain log /var/www/vhosts/system/example.com/logs/error_log might contain errors:

  [proxy:error] [pid 62521:tid 140498119395072] (111)Connection refused: AH02454: FCGI: attempt to connect to Unix domain socket /var/www/vhosts/system/example.com/php-fpm.sock (*) failed

• Unable to start PHP-FPM service. The following error “failed to open error_log” can be found when checking the status of PHP-FPM service:

  # systemctl status plesk-php55-fpm
  plesk-php55-fpm.service – The PHP 5.5.38 FastCGI Process Manager
  Loaded: loaded (/usr/lib/systemd/system/plesk-php55-fpm.service; enabled; vendor preset: disabled)
  Active: failed (Result: exit-code) since Thu 2017-07-27 17:06:38 UTC; 3min 34s ago
  Process: 6169 ExecStart=/opt/plesk/php/5.5/sbin/php-fpm –nodaemonize (code=exited, status=78)
  Main PID: 6169 (code=exited, status=78)
  example.com systemd[1]: Starting The PHP 5.5.38 FastCGI Process Manager…
  example.com php-fpm[6169]: [27-Jul-2017 17:06:38] NOTICE: PHP message: PHP Warning: PHP Startup: Unable to load dynamic library ‘/opt/plesk/ph… on line 0
  example.com php-fpm[6169]: [27-Jul-2017 17:06:38] ERROR: failed to open error_log (/var/log/plesk-php55-fpm/error.log): No such file or directory (2)
  example.com php-fpm[6169]: [27-Jul-2017 17:06:38] ERROR: failed to post process the configuration
  example.com php-fpm[6169]: [27-Jul-2017 17:06:38] ERROR: FPM initialization failed
  example.com systemd[1]: plesk-php55-fpm.service: main process exited, code=exited, status=78/n/a
  example.com systemd[1]: Failed to start The PHP 5.5.38 FastCGI Process Manager.
  example.com systemd[1]: Unit plesk-php55-fpm.service entered failed state
  example.com systemd[1]: plesk-php55-fpm.service failed.

• There is no such file or directory as the error above states:

  # ls -l /var/log/plesk-php55-fpm/error.log
  ls: cannot access /var/log/plesk-php55-fpm/error.log: No such file or directory

Cause

The error log file and/or directory for PHP-FPM service does not exist.

Resolution

1. Log in to the server via SSH .

2. If the directory is missing – create an empty directory for the corresponding handler with the command:

   # mkdir /var/log/plesk-php55-fpm/

   Note: The directory path should correspond to the affected PHP-FPM version. Change the directory path according to the one reported in errors. A few possible variants: /var/log/php-fpm/, /var/log/plesk-php56-fpm/, /var/log/plesk-php72-fpm/

3. Log into Plesk and start the corresponding service at Tools & Settings > Services Management, or directly on the server, for example, via command:

   # systemctl start plesk-php55-fpm