Site shows: ERR_CONNECTION_TIMED_OUT

Symptoms

• Apache 2.4 without nginx is used.
• Site shows Server Connection Timeout:

  ERR_CONNECTION_TIMED_OUT

• In /var/www/vhosts/system/example.com/logs/error_log below error can be found:

  [Wed Jan 31 05:50:47.216137 2018] [proxy_fcgi:error] [pid 22487:tid 139703407867648] (70007)The timeout specified has expired: [client 203.0.113.2:55437] AH01075: Error dispatching request to :, referer: http://example.com

• Domain access log contains a lot of entries that IP/IP's tried to access site or particular page:

  # cat /var/www/vhosts/system/example.com/logs/access_log |cut -f 1 -d ' '|sort|uniq -c|sort -nr
  5319 203.0.113.3
  3815 203.0.113.4

Cause

Site or page is being abused.

Resolution

Block IP's that are trying to abuse site.
Plesk > Domains > example.com >  Apache & nginx Settings > Additional directives for HTTP:

<Directory "/var/www/vhosts/example.com">
Options All
AllowOverride None
<RequireAll>
Require all granted
Require not ip 203.0.113.3 203.0.113.4
</RequireAll>
</Directory>

Additional information

Website on Plesk server is not accessible: 504 Gateway Time-out: The timeout specified has expired: [client 203.0.113.2:54693] AH01075: Error dispatching request to