title: Do browsers limit AJAX polling rate? What is the limit?
body: <p>I just read that some browsers would prevent HTTP polling (I guess by limiting the rate of requests)...</p>
  
  <p>From <a href="https://github.com/sstrigler/JSJaC" rel="noreferrer">https://github.com/sstrigler/JSJaC</a>:</p>
  
  <blockquote>
    <p>Note: As security restrictions of most modern browsers prevent HTTP
    Polling from being usable anymore this module is disabled by default
    now. If you want to compile it in use 'make polling'.</p>
  </blockquote>
  
  <p>This could explain some misbehavior of some of my JavaScripts (sometimes requests are just not sent or retried, even if they were actually successful). But I couldn't find further information on details..</p>
  
  <h2>Questions</h2>
  
  <ul>
  <li>if it's "max. number of requests n per x seconds", what are the usual/default settings for x and n?</li>
  <li>Is there any way good resource for this?</li>
  <li>Any way to detect if a request has been "delayed" or "rejected" because of a rate limit?</li>
  </ul>
  
  <p>Thanks for your help...</p>
  
  <p>Stefan</p>