Unable to upload large files via PHP on Plesk server: HTTP request length exceeds MaxRequestLen

Nikita Zubovich

Updated September 28, 2023 22:40

Plesk for Linux kb: technical

Applicable to:

Trying to upload large files on a domain via PHP application results in 550 internal server error or 502 Bad Gateway errors
If nginx support is enabled on the server, the domain's Apache error log /var/www/vhosts/system/example.com/logs/error_logcontains the following record:

mod_fcgid: HTTP request length ... (so far) exceeds MaxRequestLen (1310720)
The domain's nginx error log /var/www/vhosts/system/example.com/logs/proxy_error_logcontains the following record:

upstream prematurely closed connection while reading response header from upstream

The FcgidMaxRequestLen and/or FcgidMaxRequestInMem directive values are insufficient.

Server-wide

This only works with FPM application served by Apache, otherwise use custom templates

Connect to the server via SSH.

Note: if direct SSH access to the server is not possible, contact server administrator for further assistance.
Edit fcgid.conf file which is located in /etc/httpd/conf.d/ (for RHEL based OS) or /etc/apache2/mods-available/ (for Debian based OS).
Set FcgidMaxRequestLen and FcgidMaxRequestInMem with the same values in bytes. For example, 1024 MB corresponds to 1073741824 B.
Restart Apache:

For RHEL-based OS

# service httpd restart

For Debian-based OS:

# service apache2 restart

Warning: restarting Apache would cause downtime for the hosted domains

For specific domains