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--- mysql:changemasters [2015/06/24 18:08] – [First: make future-master to become an slave of master] rlunaro
+++ mysql:changemasters [2015/06/24 18:59] – rlunaro
@@ Line 62: / Line 62: @@
 </WRAP>
+The synchronization will be finished when --for instance-- this value shows this:
+<code>
+Slave_SQL_Running_State: Slave has read all relay log; waiting for the slave I/O thread to update it
+</code>
-This explains how to change the master of a running mysql database by the mechanism of:
+I've compared the value ''Read_Master_Log_Pos'' with other slave just to
+make sure all the changes were updated.
-  - Create a new slave wihtout downtime
+===== Second: make the slave to change the master =====
-  - Stop the current master and start a new master (the last slave)
+We have this:
+{{ :mysql:20150623_mysql_step_1.png?200 |}}
+And now we want this:
+{{: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>
+==== 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';
+</code>
+And I've stopped and started the slave.
-https://dev.mysql.com/doc/refman/5.0/en/replication-solutions-switch.html