How To Set Up Database Replication In MySQL - Page 2

2 Configure The Slave

On the slave we first have to create the database exampledb:

mysql -u root -p
Enter password:
CREATE DATABASE exampledb;
quit;

If you have made an SQL dump of exampledb on the master and have transferred it to the slave, then it is time now to import the SQL dump into our newly created exampledb on the slave:

mysql -u root -p<password> exampledb < /path/to/exampledb.sql (Replace <password> with the real password for the MySQL user root! Important: There is no space between -p and <password>!)

If you want to go the LOAD DATA FROM MASTER; way then there is nothing you must do right now.

Now we have to tell MySQL on the slave that it is the slave, that the master is 192.168.0.100, and that the master database to watch is exampledb. Therefore we add the following lines to /etc/mysql/my.cnf:

server-id=2
master-host=192.168.0.100
master-user=slave_user
master-password=secret
master-connect-retry=60
replicate-do-db=exampledb

Then we restart MySQL:

/etc/init.d/mysql restart

If you have not imported the master exampledb with the help of an SQL dump, but want to go the LOAD DATA FROM MASTER; way, then it is time for you now to get the data from the master exampledb:

mysql -u root -p
Enter password:
LOAD DATA FROM MASTER;
quit;

If you have phpMyAdmin installed on the slave you can now check if all tables/data from the master exampledb is also available on the slave exampledb.

Finally, we must do this:

mysql -u root -p
Enter password:
SLAVE STOP;

In the next command (still on the MySQL shell) you have to replace the values appropriately:

CHANGE MASTER TO MASTER_HOST='192.168.0.100', MASTER_USER='slave_user', MASTER_PASSWORD='<some_password>', MASTER_LOG_FILE='mysql-bin.006', MASTER_LOG_POS=183;

  • MASTER_HOST is the IP address or hostname of the master (in this example it is 192.168.0.100).
  • MASTER_USER is the user we granted replication privileges on the master.
  • MASTER_PASSWORD is the password of MASTER_USER on the master.
  • MASTER_LOG_FILE is the file MySQL gave back when you ran SHOW MASTER STATUS; on the master.
  • MASTER_LOG_POS is the position MySQL gave back when you ran SHOW MASTER STATUS; on the master.

Now all that is left to do is start the slave. Still on the MySQL shell we run

START SLAVE;
quit;

That's it! Now whenever exampledb is updated on the master, all changes will be replicated to exampledb on the slave. Test it!


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