django中的反向Ajax模块构建通知系统。

I am using python and django to build an application. I want to build notification system as in facebook notification. What I want is as soon as the database gets updated, a user gets notified about the changes. For that I don't want to use ajax and make asynchronous request every time-interval instead what I want is the server to push the changes to the client. Is that possible? If yes how can I do that? I am using python and django to build an applic