3 Jump Steps to Configure Master Slave Replication in Mysql

Master slave replication in mysql offload some queries from one server to other. The best advantage of master slave is to use master for all inserts and send some select queries to slave. This practice may increase speed of your application without going into optimization of all queries or buying more RAM.

This master slave configuration can be done in 3 follow steps like:

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First connet to your server via putty or open terminal directly

Step 1: Setup Master configuration file properties

Open my.cnf file

	vi /etc/my.cnf

.

And comment lines like below

	#skip-networking
	#bind-address = 127.0.0.1

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we have to tell MySQL for which database it should write logs (these logs are used by the slave to see what has changed on the master)

	log-bin = /var/lib/mysql/mysql-bin.log
	binlog-do-db=database_name_to_replication
	server-id=1

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restart mysql

	service mysqld restart

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Step 2: Setup Master configuration for replication user

logon to mysql server

mysql

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create an user with “replication slave on” privileges

GRANT REPLICATION SLAVE ON *.* to 'replication_user'@'%' IDENTIFIED BY 'password';
FLUSH PRIVILEGES;
GRANT RELOAD ON *.* TO 'replication_user'@'%'
GRANT SUPER ON *.* TO 'replication_user'@'%'
FLUSH PRIVILEGES;

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Flush tables in our database:

USE database_name_to_replication;
FLUSH TABLES WITH READ LOCK;

SHOW MASTER STATUS;

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you will see like this:-

+------------------+----------+--------------+------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000010 |      106 | db to replicate| mysql            | 
+------------------+----------+--------------+------------------+
1 row in set (0.01 sec)
==============================================

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Step 3: Setup Slave configuration file

Open my.cnf file

	vi /etc/my.cnf

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And commands lines like below

	server-id=2
	master-host = host_to_master_server
	master-user = replication_user
	master-password = password
	master-port = 3306
	master-connect-retry=60
	replicate-do-db=database_name_to_replication

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Connect to MySql

mysql

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CREATE DATABASE database_name_to_replication;

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Restart mysql

	service mysqld restart

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Run below commands:-

STOP SLAVE;
RESET SLAVE;
START SLAVE;
SHOW SLAVE STATUS;

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the output will be somthing like this:-

Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.16.4
Master_User: replication_user
Master_Port: 3306
Connect_Retry: 60
.............

.

now we should load data from our master…

LOAD DATA FROM MASTER;

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or… you can always use below command to load the initial data from master

mysql -usome_user_name -psome_password -Ddatabase_name_to_replication < dump_from_master_db.sql

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after our data is moved to slave server… we can unlock our tables.
Log in to MySQL sever (master) and:

USE database_name_to_replication;
UNLOCK TABLES;

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Now just browse your database on master and slave servers. Put some new data on master database, browse the slave database.

Hey you have new data on your slave system.

All Done!
Cheers!!