Skip to content
  • Solutions
    By Role
    • For Developers
    • For Content Managers
    • For Agencies
    • For IT Admins
    • For Web Hosters
    • For Developers
    • For Content Managers
    • For Agencies
    • For IT Admins
    • For Web Hosters
    By Infrastructure
    • Overview
    • AWS
    • Microsoft Azure
    • Alibaba Cloud
    • Google Cloud Platform
    • Vultr
    • Overview
    • AWS
    • Microsoft Azure
    • Alibaba Cloud
    • Google Cloud Platform
    • Vultr
    • Digital Ocean
    • Linode
    • Upcloud
    • Oracle
    • OVH
    • Digital Ocean
    • Linode
    • Upcloud
    • Oracle
    • OVH
  • Product
    • Plesk Features
    • Plesk Editions
    • What’s new
    • Pricing
    • Roadmap
    • Lifecycle Policy
    • Extensions Catalogue
  • Pricing
  • Extensions
    Featured Extensions
    • SocialBee
    • WP Toolkit
    • Sitejet Builder for Plesk
    • SEO Toolkit
    • Joomla! Toolkit
    • Premium Email
    • Email Security
    • SocialBee
    • WP Toolkit
    • Sitejet Builder for Plesk
    • SEO Toolkit
    • Joomla! Toolkit
    • Premium Email
    • Email Security
    Bundles and packs:
    • Business and Collaboration Edition
    • WP pack
    • Hosting pack
    • Power pack
    • Language pack
    • Business and Collaboration Edition
    • WP pack
    • Hosting pack
    • Power pack
    • Language pack

    See all Extensions

  • For Partners
    • Plesk Contributor Program
    • Plesk Partner Program
    • Affiliate program
    • Plesk University
  • Help Center
    • Documentation
    • Professional Services
    • Support
    • Contact Us
    • Wiki
    • Forum
  • Plesk 360 login
  • Free Trial
  • Pricing
  • Solutions
    • By Role
      • For Developers
      • For Content Managers
      • For Agencies
      • For IT Admins
      • For Web Hosters
    • By Infrastructure
      • Overview
      • Plesk on Amazon Web Services (AWS & Lightsail)
      • Microsoft Azure
      • Alibaba Cloud
      • Google Cloud Platform
      • Vultr
      • DigitalOcean
      • Linode
      • UpCloud
      • Oracle
      • OVH
  • Products
  • Pricing
  • Extensions
    • Featured Extensions
      • SocialBee
      • WP Toolkit
      • Sitejet Builder for Plesk
      • SEO Toolkit
      • Joomla! Toolkit
      • Premium Email
      • Email Security
    • Bundles and packs:
      • Business and Collaboration Edition
      • WP pack
      • Hosting pack
      • Power pack
      • Language pack
      • See all Extensions
  • For Partners
    • Plesk Contributor Program
    • Plesk Partner Program
    • Affiliate Program
    • Plesk University
  • Help Center
    • Documentation
    • Professional Services
    • Support
    • Contact Us
    • Wiki
    • Forum
  • Plesk 360 login
  • Free Trial
  • Pricing
  • Solutions
    • By Role
      • For Developers
      • For Content Managers
      • For Agencies
      • For IT Admins
      • For Web Hosters
    • By Infrastructure
      • Overview
      • Plesk on Amazon Web Services (AWS & Lightsail)
      • Microsoft Azure
      • Alibaba Cloud
      • Google Cloud Platform
      • Vultr
      • DigitalOcean
      • Linode
      • UpCloud
      • Oracle
      • OVH
  • Products
  • Pricing
  • Extensions
    • Featured Extensions
      • SocialBee
      • WP Toolkit
      • Sitejet Builder for Plesk
      • SEO Toolkit
      • Joomla! Toolkit
      • Premium Email
      • Email Security
    • Bundles and packs:
      • Business and Collaboration Edition
      • WP pack
      • Hosting pack
      • Power pack
      • Language pack
      • See all Extensions
  • For Partners
    • Plesk Contributor Program
    • Plesk Partner Program
    • Affiliate Program
    • Plesk University
  • Help Center
    • Documentation
    • Professional Services
    • Support
    • Contact Us
    • Wiki
    • Forum
  • Plesk 360 login
  • Free Trial
Plesk 360 login
Free Trial

Knowledge Base

A site that uses a specific PHP-FPM handler on a Plesk server does not open: 503 Service Unavailable

 
apachedomainsfastcgigohttp

Symptoms

  • The domain example.com that displays one of the following errors when opened in a browser:

    503 Service Unavailable

    502 Bad Gateway
    Nginx

  • Errors that are similar to the following appear in the domain's Apache error log /var/www/vhosts/system/example.com/logs/error_log:

    CONFIG_TEXT: [proxy:error] [pid 15065:tid 139826443527936] (111)Connection refused: AH02454: FCGI: attempt to connect to Unix domain socket /data/vhosts/system/example.com/php-fpm.sock (*) failed
    [proxy_fcgi:error] [pid 15065:tid 139826443527936] [client 203.0.113.2:50232] AH01079: failed to make connection to backend: httpd-UDS

  • Errors that are similar to the following appear in the domain's nginx error log:

    2024/02/12 10:31:43 [error] 26259#0: *595 connect() to unix:/var/www/vhosts/system/example.com/php-fpm.sock failed (111: Connection refused) while connecting to upstream, client: 2001:db8:f61:a1ff:0:0:0:80, server: example.com, request: "GET / HTTP/2.0", upstream: "fastcgi://unix:/var/www/vhosts/system/example.com/php-fpm.sock:", host: "example.com"

Cause

The PHP configuration file that should exist for the PHP version that the affected domain is set to use is missing from the /opt/plesk/php/X.X/etc/php-fpm.d/ directory.

Note: This can often occur if a PHP handler was removed entirely from Plesk, as explained in this article.

Resolution

Regenerate the PHP configuration files for the domains on your server by executing the following steps:

For a single domain
For all domains

  1. Log into Plesk
  2. Go to Domains > example.com > Dashboard > PHP, change the used PHP handler to any different one and press Apply

  3. Change the PHP handler version back to the original one and press Apply

  1. Log into the server via SSH

    Note: If direct SSH access to the server is not possible, contact server administrator for further assistance.

  2. Execute the following command to update settings on all domains:

    # /usr/local/psa/bin/php_settings -u

  3. Execute the command to get a list of all installed PHP handlers:

    # plesk bin php_handler --list | grep -E plesk.*fpm | awk -F" " '{ print $1 }'

    plesk-php74-fpm
    plesk-php81-fpm
    plesk-php82-fpm
    plesk-php83-fpm

  4. Restart the PHP handler service for all of the used PHP handlers, for example:

    # systemctl restart plesk-php74-fpm

    # systemctl restart plesk-php81-fpm

    # systemctl restart plesk-php82-fpm

    # systemctl restart plesk-php83-fpm

Tweet
Share
Share
Email
0 Shares
Read the full article
Related Posts

How to Host a Go App on Plesk

Read More »

Your Complete .htaccess Guide: Including .htaccess Basics and More

Read More »

NGINX vs Apache – Which Is the Best Web Server in 2024?

Read More »
Knowledge Base

Websites hosted on Plesk server are unavailable with 502 Bad Gateway: upstream sent too big header while reading response header

Read More »

Websites on PHP-FPM are unavailable or loading slowly: server reached max_children setting (*), consider raising it

Read More »

 Website pages based on WordPress show “404 Not Found” when PHP-FPM by Apache is used

Read More »

How to configure Apache to process PHP code inside an .html file on a Plesk server

Read More »

Hosting Wiki

  • Django
  • Server Redundancy
  • Google Cloud CDN
  • CGI
  • Bare Metal Server
  • PhpMyAdmin
  • phpPgAdmin
  • Oracle VM Server
  • Server Virtualization Software
  • Windows Server
  • Linux
  • PHP
  • MongoDB
  • HTTP/3
  • HTTP/2
  • Domain
  • Plesk
  • Lighttpd
  • Apache Tomcat
  • NGINX
  • Apache
  • Web Server
  • DNS Server
  • SSH
  • HTTP
X-twitter Linkedin Youtube Reddit Github
  • Product
  • Login
  • Pricing
  • Editions
  • For Partners
  • Partner Program
  • Contributor Program
  • Affiliate Program
  • Plesk University
  • Company
  • Blog
  • Careers
  • Events
  • About Plesk
  • Our Brand
  • Resources
  • User and Admin guides
  • Help Center
  • Migrate to Plesk
  • Contact Us
  • Hosting Wiki
  • Forum
  • Legal
  • Legal
  • Privacy Policy
  • Imprint

© 2025 WebPros International GmbH

Part of the WebPros®  Family