Which connection is suitable for my case?

Hi,

I’m new to openfire and xmpp.

I want to divide openfire into two servers, one for instant message, another for user management. The later, named core-server, provides user-auth,roster-management, even presence-service, not only for instant message ,but also for other (web) applications. The two servers still communicate with XMPP. Which connection is suitable for it? And the same question between core-server and applications. The AuthProvider is not enough for my use case.

Thanks for any opinion.