.htaccess GZIP Compression & Enable Keep-alive

To make faster webpage loading, use Gzip compress and Enable keep-alive in htaccess

<ifModule mod_deflate.c>
    AddOutputFilterByType DEFLATE text/text text/html text/plain text/xml text/css application/x-javascript application/javascript
</ifModule>

<ifModule mod_headers.c> 
	Header set Connection keep-alive 
</ifModule>

In Plesk Control Panel, follow below steps

1. Access SSH as root user
2. Go to /var/www/vhosts/{domain}/conf
3. Create or Modify vhosts.conf
4. Add following code

   #
   # KeepAlive: Whether or not to allow persistent connections (more than
   # one request per connection). Set to "Off" to deactivate.
   #
   KeepAlive On
   
   #
   # MaxKeepAliveRequests: The maximum number of requests to allow
   # during a persistent connection. Set to 0 to allow an unlimited amount.
   # We recommend you leave this number high, for maximum performance.
   #
   MaxKeepAliveRequests 30
   
   #
   # KeepAliveTimeout: Number of seconds to wait for the next request from the
   # same client on the same connection.
   #
   KeepAliveTimeout 2

    

5. Execute following command in shell

   /usr/local/psa/admin/sbin/httpdmng --reconfigure-domain <domain_name>