title: How to debug a "pending" HTTP request to a PHP web app?
body: <p>I'm maintaining an old CodeIgniter web app.</p>
  
  <p>Lately, when certain forms are saved, the browser shows a permanent "Pending" for the status of the request. The request never completes (unless I reboot the web server in which case it errors out immediately).</p>
  
  <p>There aren't any client-side errors in Dev Tools.</p>
  
  <p>There aren't any server-side errors in the logs.</p>
  
  <p>This happens in different browsers.</p>
  
  <p>It happens in a Chrome incognito window with no extensions loaded.</p>
  
  <p>All I have to go on is, the submit button it hit, the browser says "waiting for <code>&lt;servername&gt;</code>" and nothing else happens.</p>
  
  <p>Does this look like a network problem? There was no problem loading any of the application's other pages, all of which came out of the same database and web server.</p>
  
  <p>How do I debug a "pending" HTTP request in a browser, when neither the client or the server shows an error?</p>
  
  <p>TIA</p>