The doc https://httpd.apache.org/docs/trunk/mod/mod_buffer.html says that BufferSize Directive of mod_buffer module can be used within server config, virtual host, directory, .htaccess but when I try using it inside below Virtualhost Config, <VirtualHost *:8080> ProxyRequests On ProxyVia On BufferSize 131072 ErrorLog /home/juice/fp_error.log CustomLog /home/juice/fp_access.log combined <Proxy *> Order deny,allow Allow from all </Proxy> </VirtualHost> I'm getting the below error AH00526: Syntax error on line 64 of /etc/apache2/sites-enabled/mlw.conf: BufferSize not allowed in <VirtualHost> context Action 'configtest' failed. how to use this module and set both InputFilter and OutputFilter? there is no enough documentation and example snippets on how to use this module.