title: 502 bad gateway and codeigniter/nginx/apache. Code or server issue?
body: <p>My codeigniter application is running against a 502 bad gateway error. I know there are other threads on this subject, but I am no server wizard, the symptoms are different and my server config is slightly different as well, or so I think.</p>
  
  <p>This is my situation.</p>
  
  <ul>
  <li>The application works fine, until I post a form for the nth time (n being anywhere between 2 and n times). This nth time is exactly the same as the earlier postings. I just change one field and then press the submit button.</li>
  <li>The form uses the validation class, and I customized the error message setter in such a way that these messages are also set as flashdata in the session (I want the messages to be available after a redirect).</li>
  <li>My server uses Nginx and apache (Plesk, apache service daemon is called httpd). If I do "service httpd stop" or "service nginx stop" all my websites stop working immediately. </li>
  <li>There are no errors in the error log. </li>
  </ul>
  
  <p>My question is this: Could this be a coding issue, or is it most definately (or most likely) a misconfiguration of the server? If it is the latter, all advice is welcome of course, but remember it is a plesk/apache/nginx environment.</p>
  
  <p>Hope you guys can help! </p>