title: PHP: Default /tmp sessions VS session_set_save_handler() performance
body: <p>During my research I have found opinions pointing in both directions on this issue. A discussion would be appreciated to clarify this issue.</p>
  
  <p>We are aware of the obvious advantageous security aspects on storing the session data in the database.</p>
  
  <p><strong>Option 1:</strong></p>
  
  <blockquote>
    <p>Using the default session storage on the filesystem (defaults to /tmp)</p>
  </blockquote>
  
  <p><strong>Option 2:</strong></p>
  
  <blockquote>
    <p>Using <a href="http://www.php.net/manual/en/function.session-set-save-handler.php" rel="nofollow">session_set_save_handler()</a> to
    store the session data in the/a
    database.</p>
  </blockquote>
  
  <hr>
  
  <p><strong>My questions are:</strong></p>
  
  <ol>
  <li>On a high traffic site, what example would give the best performance?</li>
  <li>Is this a matter of system hardware and where the current bottlenecks on this specific site are? In this case, the site is heavily pointed toward displaying specific user data from the database. Possibly this would be a question in need of serverfault input.</li>
  <li>The site will probably have to propagate on to multiple servers soon, to deal with load and accessibility from other parts of the world. Think CDN. Does this affect my decision? I'm thinking it would be much easier to manage session information between the different computers if it is stored in the database.</li>
  </ol>