3 replication servers but act as different master/slave to each other (3 replies)

Hi,

Says I have three database servers (machine):
DBServer1 (Machine A)
DBServer2 (Machine B)
DBServer3 (Machine C)

DBServer1 has database ABC and database DEF.
DBServer2 has database ABC only.
DBServer3 has database DEF only.

I want to:
DBServer1 replicates data with DBServer2.
DBServer1 replicates data with DBServer3.

I found some constraints when I want to do the configuration.
As I know I can only configure one master host in my.cnf file. Besides, if I add replicate-do-db=ABC in DBServer1, my DBserver3 will find there's no such db=ABC to be replicated.

I google, it says I need to install two mysql server in order to have two my.cnf and locate in different location.

I wish to know is there any other ways to solve this problem?
Appreciate your help.

P/S:
DBServer1 is master of DBServer2
DBServer2 is master of DBServer1
DBServer1 is master of DBServer3
DBServer3 is master of DBServer1


Thanks!