I have a master mysql server (M1) with two replicating slaves behind it. I also have another master mysql server (M2) with it's two slave servers. The slave servers currently replicate everything from it's respective master.
I would need to change one master server (M1) so that it replicates some tables from M2. The tables it (M1) will replicate will be set as read-only (user privilege will be changed).
This is a production set up. I would like to know whether it is possible? If so, how?