mysql database replication : How To Step by Step: master -slave replication
Here we will help you to setup master-slave replication between MySQL servers.
Setup Details:
Master Server: 10.0.10.12
Slave Server: 10.0.10.18
Database: empmaster
1. Setup MySQL Master Server
- Create an mysql account on Master server with REPLICATION SLAVE privileges to which replication client will connect to master.
- Block write statement on all the tables, so not changes made after taking backup.
- Edit MySQL configuration file and add the following lines under [mysqld] section.
- Restart master mysql server to changes take effect.
- Check the current binary log file name (File) and current offset (Position) value using following command.
mysql> GRANT REPLICATION SLAVE ON *.* TO 'repl_user'@'10.0.10.18' IDENTIFIED BY 'secretpassword';
mysql> FLUSH PRIVILEGES;
mysql> use empmaster;
mysql> FLUSH TABLES WITH READ LOCK;
mysql> exit;
# vim /etc/my.cnf
[mysqld]
log-bin=mysql-bin
binlog-do-db=empmaster
server-id=1
innodb_flush_log_at_trx_commit=1
sync_binlog=1
# service mysqld restart
mysql > SHOW MASTER STATUS;
+------------------+----------+--------------+------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000002 | 107 | empmaster | |
+------------------+----------+--------------+------------------+
The above output is showing that the current binary file is using mysql-bin.000002 and offset value is107. Note down these values to use on slave server.
- Take a backup of database and copy it to slave mysql server.
- After completing backup remove the READ LOCK from tables, So that changes can be made.
- Edit salve mysql configuration file and add following values under [mysqld] section.
# mysqldump -u root -p empmaster > empmaster.sql
# scp empmaster.sql 10.0.10.18:/opt/
mysql> UNLOCK TABLES;
2. Setup MySQL Slave Server
# vim /etc/my.cnf
[mysqld]
server-id=2
replicate-do-db=empmaster
server-id always be an non zero numeric value. These value will never be similar with other master and slave servers.
- Restart mysql slave server, If you had already configured replication use –skip-slave-start in start to not to immediate connect to master server.
- Restore database backup taken from master server.
- Setup option values on slave server using following command.
- Finally start the slave thread
- Check the status of slave server.
# /etc/init.d/mysqld restart
# mysql -u root -p empmaster < empmaster.sql
mysql> CHANGE MASTER TO MASTER_HOST='10.0.10.12',
-> MASTER_USER='repl_user',
-> MASTER_PASSWORD='secretpassword',
-> MASTER_LOG_FILE='mysql-bin.000002',
-> MASTER_LOG_POS=107;
mysql> SLAVE START;
mysql> show slave status \G
*************************** 1. row ***************************
Slave_IO_State:
Master_Host: 192.168.1.15
Master_User: repl_user
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000002
Read_Master_Log_Pos: 107
Relay_Log_File: mysqld-relay-bin.000001
Relay_Log_Pos: 4
Relay_Master_Log_File: mysql-bin.000002
Slave_IO_Running: No
Slave_SQL_Running: No
Replicate_Do_DB: empmaster
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 107
Relay_Log_Space: 107
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: NULL
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 1
1 row in set (0.00 sec)
mysql>
MySQL Master-slave Replication has been configured successfully on your system and in working mode.
