http://simonwillison.net/2008-05-15T07:55:36+00:00Simon Willison2008-05-15T07:55:36+00:002008-05-15T07:55:36+00:00https://simonwillison.net/2008/May/15/engineering/#atom-tag

<p><strong><a href="http://www.facebook.com/note.php?note_id=14218138919&amp;id=9445547199&amp;index=0">Engineering @ Facebook: Facebook Chat</a></strong></p> The new Facebook Chat uses Comet (long polling with a hidden iframe) against a custom web / chat server written in Erlang, designed to handle a launch to all 70 million users at once. It was tested using a “dark launch” period where live pages simulated chat request traffic without showing any visible UI. <p>Tags: <a href="https://simonwillison.net/tags/comet">comet</a>, <a href="https://simonwillison.net/tags/darklaunch">darklaunch</a>, <a href="https://simonwillison.net/tags/erlang">erlang</a>, <a href="https://simonwillison.net/tags/facebook">facebook</a>, <a href="https://simonwillison.net/tags/javascript">javascript</a>, <a href="https://simonwillison.net/tags/scaling">scaling</a></p>