Question

My website is very dynamic and its collecting data from the database. while I was testing I pressed the refresh key and hold it for some time, the server went down. (This is a simple DoS attack). How can I stop user to keep hitting the refresh button.
Can anyone tell me the solution for that. Like gmail does, go to gmail account and press F5 and hold it for some time. Gmail will display this message

“We’re sorry, but your Gmail account is temporarily unavailable. We apologize for the inconvenience and suggest trying again in a few minutes. You can view the Apps Status Dashboard for the current status of the service.”

Thanks

Answer 1

Why not use the counter approach. Increase it till a threshold is reached within a small interval and if so then block access.

The JSP for it would be something like this

 <% 
        int refresh;
        if(session.getAttribute("pageRefresh")==null)
             refresh=0;
        else
            refresh = (Integer)session.getAttribute("pageRefresh") + 1;


       session.setAttribute("pageRefresh", refresh); 

       session.setMaxInactiveInterval(10000);

       if (refresh>100)
       {
           //error message or black list client
       }
%>