how to for mysql master master replication

Here  is a basic step by step tutorial, that will cover the mysql master and slave replication and also will describe the mysql master and master replication.

Notions: we will call system 1 as master1 and slave2 and system2 as master2 and slave 1
 Step 1:

Install mysql on master 1 and slave 1. configure network services on both system, like

Master 1/Slave 2 ip: 192.168.16.4
Master 2/Slave 1 ip : 192.168.16.5

Step 2:

On Master 1, make changes in my.cnf:
[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
old_passwords=1

log-bin
binlog-do-db=<database name>  # input the database which should be replicated
binlog-ignore-db=mysql            # input the database that should be ignored for replication
binlog-ignore-db=test

server-id=1

[mysql.server]
user=mysql
basedir=/var/lib


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

Step 3:

On master 1, create a replication slave account in mysql.

mysql> grant replication slave on *.* to 'replication'@192.168.16.5 \
identified by 'slave';

and restart the mysql master1.

Step 4:

Now edit my.cnf on Slave1 or Master2 :
[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
old_passwords=1

server-id=2

# for auto increment fields
replicate-same-server-id = 0
auto-increment-increment = 2
auto-increment-offset = 2
 
master-host = 192.168.16.4
master-user = replication
master-password = slave
master-port = 3306

[mysql.server]
user=mysql
basedir=/var/lib

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

Step 5:

Restart mysql slave 1 and at

mysql> start slave;
mysql> show slave status\G;

Step 6:

On master 1:
mysql> show master status;

Note:The above scenario is for master-slave, now we will create a slave master scenario for the same systems and it will work as master master. 

Step 7:

On Master2/Slave 1, edit my.cnf and master entries into it:
 [mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
# Default to using old password format for compatibility with mysql 3.x
# clients (those using the mysqlclient10 compatibility package).
old_passwords=1
server-id=2

master-host = 192.168.16.4
master-user = replication
master-password = slave
master-port = 3306

log-bin                     #information for becoming master added
binlog-do-db=adam

[mysql.server]
user=mysql
basedir=/var/lib
[mysqld_safe]
err-log=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid

Step 8:

Create a replication slave account on master2 for master1:

mysql> grant replication slave on *.* to 'replication'@192.168.16.4 identified by 'slave2';

Step 9:

Edit my.cnf on master1 for information of its master.
[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock

# Default to using old password format for compatibility with mysql 3.x
# clients (those using the mysqlclient10 compatibility package).
old_passwords=1


log-bin
binlog-do-db=adam
binlog-ignore-db=mysql
binlog-ignore-db=test

server-id=1
replicate-same-server-id = 0
auto-increment-increment = 2
auto-increment-offset = 1

#information for becoming slave.
master-host = 192.168.16.5
master-user = replication
master-password = slave2
master-port = 3306
[mysql.server]user=mysqlbasedir=/var/lib 

Step 10:

Restart both mysql master1 and master2.
On mysql master1:

mysql> start slave;

On mysql master2:

mysql > show master status;

On mysql master 1:

mysql> show slave status\G;

Reference url:Mysql master master replication