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--- mysql:changemasters [2015/06/24 16:13] – [First: make future-master to become an slave of master] rlunaro
+++ mysql:changemasters [2022/12/02 21:02] (current) – external edit 127.0.0.1
@@ Line 71: / Line 71: @@
 make sure all the changes were updated.
+===== Second: make the slave to change the master =====
+We have this:
-This explains how to change the master of a running mysql database by the mechanism of:
+{{ :mysql:20150623_mysql_step_1.png?200 |}}
-  - Create a new slave wihtout downtime
+And now we want this:
-  - Stop the current master and start a new master (the last slave)
+{{:mysql:20150623_mysql_step_3.png?200|}}
+For that, we have to:
+  - Stop the master
+  - Check that both slaves are up-to-date
+  - issue a [[https://dev.mysql.com/doc/refman/5.0/en/replication-solutions-switch.html|change master to]] command to the old slave
+==== Stop the master ====
+Nothing new under the sun:
+<code>
+/etc/rc.d/mysql stop
+</code>
+or:
+<code>
+net stop mysql
+</code>
+==== Check that both slaves are up-to-date ====
+Among the information that ''show slave status\G'' displays, I've chosen Read_Master_Log_Pos to make sure
+both database servers are in the same position.
+==== Create (if it does not exist) a replication user in future-master ====
+<code>
+grant replication slave, replication client on *.* to YOUR-REPLICATION-USERNAME identified by 'YOUR-REPLICATION-PASSWORD';
+</code>
+==== Check master status an take note of the master log file and master log position ====
+We have to issue a ''show master status'' command to get the file and log position of our new master:
+<code>
+mysql> show master status\G
+*************************** 1. row ***************************
+             File: YOUR-MASTER-LOG-FILE
+         Position: YOUR-MASTER-LOG-POS
+     Binlog_Do_DB:
+ Binlog_Ignore_DB:
+Executed_Gtid_Set:
+row in set (0.00 sec)
+</code>
+With this two values, YOUR-MASTER-LOG-FILE and YOUR-MASTER-LOG-POS, we can move to the
+slave and issue a change master to command.
+==== Issue a change master command ====
+In the slave server I've issued a ''change master to'' command:
+<code>
+stop slave;
+change master to master_host='future-master',
+master_port=3306,
+master_user='YOUR-REPLICATION-USERNAME',
+master_password='YOUR-REPLICATION-PASSWORD',
+master_log_file = 'YOUR-MASTER-LOG-FILE',
+master_log_pos = YOUR-MASTER-LOG-POSITION;
+start slave;
+</code>
+And I've stopped and started the slave.
+===== Final check =====
+You can double check that your slave is working with the new configuration just by the method of looking
+one change made in the new master.
-https://dev.mysql.com/doc/refman/5.0/en/replication-solutions-switch.html