title: apache 2.2 to 2.4 sporadic performance drop
body: <p>I updated apache from 2.2 to 2.4 and php from 5.3 to 5.4.
  For some reason I am experiencing huge performance drops in around 5% of requests to the server. On average, sites load in less than 2 seconds but in this 5% of cases it takes anywhere between 30 to 60 seconds of spinning before the site finally loads. </p>
  
  <p>I copied my old prefork settings</p>
  
  <pre><code>StartServers       8
  MinSpareServers    5
  MaxSpareServers   10
  ServerLimit      512
  MaxClients       512
  MaxRequestsPerChild  4000:
  </code></pre>
  
  <p>Setup: 8 vCPU, 8gb ram, SSD
  CPU never goes over 30%, ram stays at around 1.8GB.</p>
  
  <p>DB is on a separate server and performs very fast. I already debugged it and never got a slow query (nothing over a minute).</p>
  
  <p>I already performed 2.2 to 2.4 update steps from here <a href="http://httpd.apache.org/docs/trunk/upgrading.html" rel="nofollow">http://httpd.apache.org/docs/trunk/upgrading.html</a>
  but it didnt help. Is there any other way to debug the server and why it slows down so badly? 
  I do not suspect the php to be the reason since the codebase did not change.</p>
  
  <p>EDIT</p>
  
  <p>I need to add that when the page is spnning, i can click on the link, press enter and there is a big chnage that it will load in under 2 seconds. Sometimes I have to hit enter or refresh this loading page 2 or 3 times and it loads immediately.</p>