It depends on your service as to whether you can even make them multi-master. For example, a single Oracle database can only be a fail-over service. There is no way it can be made multi-master, unless I suppose it was some very strange read-only database.
However, services such as directory servers (DS) or web servers can be architected to be multi-master. IIRC, the usual DS configuration is to have two replicated, multi-master DS fronting the back-end DS 'database'.
Regards,
Tim