What is Facebook's new Tornado framework?

Question

Facebook just open-sourced a framework called Tornado.

What is it? What does it help a site do?

I believe Facebook uses a LAMP structure. Is it useful for s

Answer 1

It has 'database' module with blocking queries. Maybe they run multiple instances of this server to minimize blocking problems and maybe it is not used for whole friendfeed, only in some parts related to real-time behavior (i heard that HTTP connections persist open to check for updates, and threading behavior would be bad for this).

I don't think it is usable as general-purpose framework for any web applications.