Is there a way in HTML5 (websocket perhaps?) to set up some kind of push mechanism for ajax requests? For instance, I would like my logged in user to be notified he has a new message without sending a periodic ajax request to the server checking if there actually is a new message.
Right now, I do a check every couple seconds and change the UI accordingly if I get a number back, but for 10000 users this tends to get quite demanding on the server with frequent updates.
If HTML5 does not have a native ability to handle this, is Comet (http://www.zeitoun.net/articles/comet_and_php/start) a better approach than periodic ajax calls?