2014/1/17 Richard Reina <gatorre...@gmail.com> > I have 3 relay MySQL database servers on my small office LAN backing up a > master and 3 more machines backing up each relay (1 each). They are all > replicating all databases and all tables. The master although running fine > is almost eight years old. I'm thinking it's probably time to make one of > the relays the master, but I've never done this before. > > I want the new master to have the IP address of the old master 192.168.0.1 > . To make the change I was going to take the master off the LAN and > shutdown mysql on all the machines, change the IP address on the chosen > relay to that of the master 192.168.0.1, then restart mysql on all the > machines. I always refer to the machines by their IP addresses and never by > their hostnames. Once I successfully make the change I was planning on > making the old master a relay since it is still working fine. > > Will this plan work ok? Is there a better or easier way? > > > If the three machines are sync'ed and have consistent data I don't see the need of stopping MySQL:
- Stop whatever writes to your current master - Once you are completely sure there are no writes in your current master, set it to read_only = ON - In the slave which will become the master, get the logfile and current position with: show master status; - Set the new IP in the new master Using the position taken in the new master go to the slaves machines and: stop slave; change master to master_host='IP', master_log_file='whatever_file_name_you_got', master_log_pos=whatever_number_you_got, master_user='replication_or_whatever_you_have', master_password='replication_or_whatever_you_have'; start slave; - Set read_only = OFF in your new master - Start your application so you can start getting writes again. As soon as you get writes if you do a "show master status;" in the new master you should see the position going forward. I see that faster than any other thing. Hope this helps Manuel.
