Maximum Number of users can Openfire support

We are intended to use openfire for a chatting application. How many users openfire server can support if we use it in clusting mode.

can we serve Milions of users ?

and what are the recommended configrations for the hardware servers for 1 million users?

In theory if your local server, per room, you can create: 10,20,30,40,50, ilimited (clients)

but if you have about 10,000 rooms, with 5 or 6 users, within them, thinks your pc go slower, because you need to listen to all requests in theory

See

http://community.igniterealtime.org/docs/DOC-1543