[users@httpd] Forward ssl requests to non-ssl page using proxy

[YungWei.Chen]

Hi,
    I am trying to set up a reverse proxy server, which accepts only ssl
requests. 
    If the proxy server forwards requests to an ssl page, it will work. 
    But if the proxy server forwards requests to a non-ssl page, I will
get 503 Service Temporarily Unavailable error. 
    Does it have to be ssl-to-ssl and http-to-http? If so, why? Thanks.
 
<VirtualHost *:443>
    ....
    ....
   
   SSLProxyEngine On
   <Location / >
       Order Deny,Allow
       Deny from all
       Allow from 192.168.12
       ProxyPass        http://192.168.12.31:8888/  
       ProxyPassReverse http://192.168.12.31:8888/
       ProxyPassReverseCookieDomain 192.168.12.31:8888 192.168.12.21
   </Location>
</VirtualHost>