Let\'s say I want to use Google GWT on the client side and Google AppEngine Python on the server side. Furthermore, I want to be able to use RPC calls to the server as well
One year later, the new Channel API available in GAE allows this kind of persistent connections to avoid polling both in Java and Python.
"The Channel API creates a persistent connection between your application and Google servers, allowing your application to send messages to JavaScript clients in real time without the use of polling. This is useful for applications that are designed to update the user about new information immediately or where user input is immediately broadcast to other users. Some examples include collaborative applications, multi-player games, and chat rooms. In general, using Channel API is a better choice than polling in situations where updates can't be predicted or scripted, such as when relaying information between human users or from events not generated systematically."