- Plesk for Linux
Unable to create domain via WHMCS, which is installed on the same server with Plesk. The following error appears when pressing Accept Order button in WHMCS:
PLESK_INFO: Server Error 503 - Service Temporarily Unavailable
CONFIG_TEXT: [201631 2017] [proxy_fcgi:error] pid 25317:tid 140358851684096 Connection reset by peer: [client 203.0.113.2:55048] AH01075: Error dispatching request to : , referer: http://example.com/admin/test.php?userid=8&id=8&success=true
[proxy_fcgi:error] [pid 25588:tid 140358918825728] [client 203.0.113.2:55078] AH01067: Failed to read FastCGI header, referer: http://example.com/admin/test.php?userid=8&id=8&success=true
CONFIG_TEXT: [error] 18285#0: *1859 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: 203.0.113.2, server:example.com, request: "GET /cart.php?a=complete HTTP/1.1", upstream: "fastcgi://unix:///var/www/vhosts/system/example.com/php-fpm.sock:", host: "example.com", referrer: "http://example.com/cart.php?a=checkout"
Creation of a new domain in Plesk implies web server restart, what affects WHMCS functionality.
In case WHMCS domain is hosted on Plesk, change its PHP handler to FPM + Nginx:
Go to Domains > whmcs.example.com > PHP Settings > run PHP as FPM application served by nginx
Warning: Make sure that new domains are created with a different PHP FPM handler, otherwise WHMCS will not be able to handle the request because the PHP FPM will be restarted.
Note: It is not recommended to place WHMCS and Plesk on the same server, as they can use the same shared resources.