MySQL Replication

*** TESTED FOR CENTOS 7 ***

NEED TO HAVE PORT 3306 OPENED! -- MASTER = 10.1.2.117, SLAVE = 10.1.2.118

Master:

vi /etc/my.cnf
[mysqld]
bind-address = 10.1.2.117
server-id = 1
log_bin = /var/lib/mysql/mysql-bin.log
binlog-do-db=mydb
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
symbolic-links=0
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES

[mysqld_safe]
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
systemctl restart mysql

If new server without db create before you grant permissions, if you already have a db running keep reading to see how you can move your db to slave.

GRANT REPLICATION SLAVE ON *.* TO 'slave_user'@'%' IDENTIFIED BY 'password';
FLUSH PRIVILEGES;
USE mydb;
FLUSH TABLES WITH READ LOCK;

Note down the position number you will need it on a future command.

SHOW MASTER STATUS;

+------------------+----------+--------------+------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000001 |      665 | newdatabase  |                  |
+------------------+----------+--------------+------------------+
1 row in set (0.00 sec)
mysqldump -u root -p --opt mysql > mysql.sql
UNLOCK TABLES;

Slave:

CREATE DATABASE mydb;

Now import the DB from the MASTER

mysql -u root -p mydb < /path/to/mydb.sql

vi /etc/my.cnf

[mysqld]
server-id = 2
relay-log = /var/lib/mysql/mysql-relay-bin.log
log_bin = /var/lib/mysql/mysql-bin.log
binlog-do-db=mydb
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
symbolic-links=0
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES

[mysqld_safe]
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid

To add more DB's create another line with the db name: binlog-do-db=mydb2 in my.cnf

systemctl restart mysql
CHANGE MASTER TO MASTER_HOST='10.1.2.117',MASTER_USER='slave_user', MASTER_PASSWORD='password', MASTER_LOG_FILE='mysql-bin.000001', MASTER_LOG_POS=665;
START SLAVE;
SHOW SLAVE STATUS\G

Look at  Slave_IO_State & Slave_IO_Running & Slave_SQL_Running & make sure Master_LOG and Read_Master_Log_Pos matches the master.

Screenshot-20170723195816-798x255.png

If there is an issue in connecting, you can try starting slave with a command to skip over it:

SET GLOBAL SQL_SLAVE_SKIP_COUNTER = 1; 
SLAVE START;