Database replication will synchronize databases between two different servers.
Should any record change on primary server, it will be automatically sent to secondary (slave) server.

Edit MySQL config file /etc/my.cnf


server-id=1
log_bin=/var/log/mysql/mysql-bin.log


log_bin – specifies the location of MySQL binary log, which is used for replication.

You can limit the binary logging to only one database by specifying parameter binlog_do_db=database .
However this is not recommended, see (dev.mysql.com )

Save changes and restart MySQL server.
service mysql restart

Now we should grant privileges on slave user which will be used for replcation.

mysql -u root -p
GRANT REPLICATION SLAVE ON *.* TO 'slave_user'@'%' IDENTIFIED BY 'pass';
FLUSH PRIVILEGES;


Now lock and dump DB to the file to transfer it to the second server.


FLUSH TABLES READ LOCK;
SHOW MASTER STATUS;

Save “Position” field.

If you do something in this window database will automatic unlock,
you should open new window and do it there:

mysqldump -u root -p -f db1 > db1.sql
db1 – name of database, that you want to dump

Unlock database.
UNLOCK TABLES;

Now it’s time to configure secondary server.

CREATE DATABASE db1;

Import dump from first server:

mysql -u root -p -f db1 < db1.sql

Edit MySQL config file /etc/my.cnf

server-id=2
relay-log=/var/log/mysql/mysql-relay-bin.log
log_bin=/var/log/mysql/mysql-bin.log


Restart MySQL:
service mysql restart

Server configured and ready for replication.
To activate replication on slave server execute following command in mysql console:

CHANGE MASTER TO
MASTER_HOST='IP-address or primary server',
MASTER_USER='slave_user',
MASTER_PASSWORD='pass',
MASTER_LOG_FILE='mysql-bin.000001',
MASTER_LOG_POS=XXX;

Remember “Position” field from “SHOW MASTER STATUS” command and write value in place of XXX.

And start replacation:
START SLAVE;

Look at status::
SHOW SLAVE STATUS\G

Slave_IO_State: Waiting for master to send event

To stop replication use:
STOP SLAVE

PS: MySQL uses TCP port 3306 for communication, so it should be open between them.