Unable to download large files from a website in Plesk: ap_pass_brigade failed in handle_request_ipc function

Symptoms

• Unable to download a large file from a website hosted on Plesk.

• Downloading speed is not high.

• Proxy mode is enabled in Plesk > Domains > example.com > Apache & Nginx Settings.

• PHP handler set to FastCGI application server by Apache.

• Records like the following can be found in /var/www/vhosts/example.com/logs/error_log:

  [fcgid:warn] [pid 13949] (104)Connection reset by peer: [client 203.0.113.2:43210] mod_fcgid: error reading data from FastCGI server, referer: https://example.com/index.php
  [fcgid:warn] [pid 13949] (104)Connection reset by peer: [client 203.0.113.2:43210] mod_fcgid: ap_pass_brigade failed in handle_request_ipc function, referer: https://example.com/index.php

Cause

Insufficient FastCGI limits.

Resolution

1. Log into Plesk.

2. Go to Domains > example.com > PHP Settings.

3. Increase the max_execution_time value.

4. Go to Domains > example.com > Apache & Nginx Settings.

5. Add the following directives under Additional directives for HTTP & Additional directives for HTTPS:

   <IfModule mod_fcgid.c>
   FcgidMaxRequestsPerProcess 500
   FcgidBusyTimeout 3600
   FcgidMaxRequestLen 1073741824
   FcgidProcessLifeTime 7200
   </IfModule>