title: Slow Apache response
body: <p>I have a high performance softlayer server. I am only running a (php-based. It's not an IRC server) chat room on this server. It works all fine. On average server response (for chat room) is 100MS with 100+ concurrent users. Some days ago a user threat to ddos our server. Now the server is so slow. On average ping time is 1500-2000MS with just 50-60 users. There is no high resource usage or bandwidth usage. I did following things to protect my server:</p>
  
  <pre><code>1 - DDOS protection (softlayer providers it)
  2 - Install mod qos and evassive for appache
  3 - Disabled ping of death and Syn packets
  </code></pre>
  
  <p>I performed following analysis:</p>
  
  <pre><code>1 - Analyzed apache logs. There isn't any frequent request from same IP or CLRF packets.
  2 - Not many UDP packets 
  3 - Checked connections per IP and they are all normal.
  </code></pre>
  
  <p>However, nothing is working. That user threats and kills our time whenever he says/wants. Is there any other thing I should look into to protect my server? What kind of attack he could make to do this?</p>