How To Set Up Master-Slave Replication in MySQL

MySQL replication is a process that enables data from one MySQL database server (the master) to be copied automatically to one or more MySQL database servers (the slaves).

First, let’s set up 2 MySQL servers. (MySQL install)
Master Database: 10.0.0.11
Slave Database : 10.0.0.12

Change settings on Master Host

Change in /etc/my.cnf file settings and create a user for replication on MySQL

vi /etc/my.cnf

[mysqld]
log-bin=mysql-bin
server-id=11

Restart MySQL Service

#systemctl restart mysqld

create a user

#mysql -u root -p
Enter password:
mysql>grant replication slave on *.* to replica@’%’ identified by ‘password’;
Query OK, 0 rows affected (0.00 sec)
mysql>flush privileges;
Query OK, 0 rows affected (0.00 sec)
mysql> exit

Change settings on Slave Host

vi /etc/my.cnf

[mysqld]
log-bin=mysql-bin
server-id=12
read_only=1

Restart MySQL Service

#systemctl restart mysqld

Change settings on Master Host

We should lock all tables and learn show master status (remember File, Position value)

#mysql -u root -p
Enter password:
mysql>flush tables with read lock;
Query OK, 0 rows affected (0.00 sec)
mysql>show master status;
+------------------+----------+--------------+------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000005 |      212 |              |                  |                   |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)

Get Dump-Data on Master Host

#mysqldump -u root -p — all-databases — lock-all-tables — events > database_dump.sql

Copy the dump file to Slave Host

#scp database_dump.sql root@10.0.0.12:/tmp/

We should unlock all the tables

#mysql -u root -p
Enter password:
mysql>unlock tables;
Query OK, 0 rows affected (0.00 sec)
mysql>exit

Change settings on Slave Host

import dump MySQL database file

#mysql -u root -p < /tmp/database_dump.sql
Enter password:

replica settings and start replication

#mysql -u root -p
Enter password:
mysql>change master to 
->master_host='10.0.0.11',master_user='replica', 
->master_password='password', 
->master_log_file='mysql-bin.000005',
->master_log_pos=212;
Query OK, 0 rows affected (0.54 sec)
mysql>start slave;
Query OK, 0 rows affected (0.00 sec)
mysql>show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 10.0.0.11
                  Master_User: replica
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000005
          Read_Master_Log_Pos: 732
               Relay_Log_File: node01-relay-bin.000006
                Relay_Log_Pos: 460
        Relay_Master_Log_File: mysql-bin.000005
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
              Replicate_Do_DB:
          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: 632
              Relay_Log_Space: 568
              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: 0
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: 101
                  Master_UUID: 2222c042-dd31-12d6-7f68-5754505d05ae
             Master_Info_File: /var/lib/mysql/master.info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
           Master_Retry_Count: 86400
                  Master_Bind:
      Last_IO_Error_Timestamp:
     Last_SQL_Error_Timestamp:
               Master_SSL_Crl:
           Master_SSL_Crlpath:
           Retrieved_Gtid_Set:
            Executed_Gtid_Set:
                Auto_Position: 0
         Replicate_Rewrite_DB:
                 Channel_Name:
           Master_TLS_Version:
1 row in set (0.00 sec)