title: Debugging a 404 error for an existing page
body: <p>I have a PHP script on server which, generally...</p>
  
  <ol>
  <li>Receives url-encoded data via POST from Service A</li>
  <li>Makes adjustments to the data for Service B</li>
  <li>Submits to Service B</li>
  </ol>
  
  <p>This works great except that every so often, Service A reports that the script 404'd (was not found).</p>
  
  <p>I am trying to figure out two things:</p>
  
  <ol>
  <li>Why would a 404 error occur if the script exists and is accessible?</li>
  <li>I believe the issue is related to a timeout somewhere in the script. Is there a way that I can avoid the 404 error and perhaps log some helpful messages, <a href="https://stackoverflow.com/questions/8797911/debugging-php-script-timeout">like in this post</a>?</li>
  </ol>
  
  <p>Thank you!</p>