浏览一下5.5官档上关于replication的章节：
http://dev.mysql.com/doc/refman/5.5/en/replication-howto.html
总结了一下关于AB复制的步骤：
(1)设置主服务器的my.cnf 开启二进制日志记录设置serverid
[mysqld]
log-bin=mysql-bin
server-id=1
innodb_flush_log_at_trx_commit=1
sync_binlog=1
(2)设置从服务器的serverid
[mysqld]
server-id=2
(3)设置复制帐户，并授权
create user 'gabriel'@'%.richinfo.cn' identified by 'gabriel0814';
grant replication slave on *.* to 'gabriel'@'%.richinfo.cn ';
(4)锁定数据库状态，读取主服务器二进制日志的状态
flush tables with read lock;
show master status；
(5)使用mysqldump创建数据库快照,释放锁
mysqldump --all-database --lock-all-tables > dbdump.db
unlock tables;
(6)在从服务器上准备复制：
stop slave;
mysql < fulldb.dump
change master to
master_host='applinux002.richinfo.cn',
master_user='gabriel',
master_password='gabriel0814',
master_log_file='',
master_log_pos= ;
start slave;
以上步骤在自己的虚拟机上测试是通过的，在复制搭建完毕后，由于权限的问题，去掉通配符%改为实际的主机名，AB复制成功。
在生产线上具体实施步骤如下：
(1) 更改master数据库my.cnf参数：
[root@applinux002 data]# cat /etc/mysql/my.cnf | grep -v ^# | grep -v ^$
[client]
port = 3306
socket = /etc/mysql/mysqld.sock
[mysqld]
datadir = /md3200i/data1/mysql/data
port = 8808
socket = /etc/mysql/mysqld.sock
skip-external-locking
key_buffer_size = 384M
max_allowed_packet = 1M
table_open_cache = 512
sort_buffer_size = 2M
read_buffer_size = 2M
read_rnd_buffer_size = 8M
myisam_sort_buffer_size = 64M
thread_cache_size = 8
query_cache_size = 32M
thread_concurrency = 24
log-bin=mysql-bin
server-id = 1
innodb_data_home_dir = /md3200i/data1/mysql/data
innodb_data_file_path = ibdata1:2000M;ibdata2:10M:autoextend
innodb_log_group_home_dir = /md3200i/data1/mysql/data
innodb_buffer_pool_size = 2048M
innodb_additional_mem_pool_size = 20M
innodb_log_file_size = 512M
innodb_log_buffer_size = 8M
innodb_flush_log_at_trx_commit = 1
innodb_lock_wait_timeout = 50
[mysqldump]
quick
max_allowed_packet = 16M
[mysql]
no-auto-rehash
[myisamchk]
key_buffer_size = 256M
sort_buffer_size = 256M
read_buffer = 2M
write_buffer = 2M
[mysqlhotcopy]
interactive-timeout
(2) 更改slave数据库my.cnf参数：
[root@applinux003 mysql]# cat /etc/mysql/my.cnf | grep -v ^# | grep -v ^$
[client]
port = 3306
socket = /etc/mysql/mysqld.sock
[mysqld]
port = 8808
socket = /etc/mysql/mysqld.sock
skip-external-locking
key_buffer_size = 384M
max_allowed_packet = 1M
table_open_cache = 512
sort_buffer_size = 2M
read_buffer_size = 2M
read_rnd_buffer_size = 8M
myisam_sort_buffer_size = 64M
thread_cache_size = 8
query_cache_size = 32M
thread_concurrency = 8
server-id = 2
innodb_data_home_dir = /md3200i/data1/mysql/data
innodb_data_file_path = ibdata1:2000M;ibdata2:10M:autoextend
innodb_log_group_home_dir = /md3200i/data1/mysql/data
innodb_buffer_pool_size = 2048M
innodb_additional_mem_pool_size = 20M
innodb_log_file_size = 512M
innodb_log_buffer_size = 8M
innodb_flush_log_at_trx_commit = 1
innodb_lock_wait_timeout = 50
[mysqldump]
quick
max_allowed_packet = 16M
[mysql]
no-auto-rehash
[myisamchk]
key_buffer_size = 256M
sort_buffer_size = 256M
read_buffer = 2M
write_buffer = 2M
[mysqlhotcopy]
interactive-timeout
(3) 创建复制用户，并授权由于在测试环境中运用通配符%发生了错误，在生产环境
中直接对真实主机名进行授权。
mysql> create user 'replica'@'applinux003.richinfo.cn' identified by 'replica';
Query OK, 0 rows affected (0.00 sec)
mysql> grant replication slave on *.* to 'replica'@'applinux003.richinfo.cn';
Query OK, 0 rows affected (0.00 sec)
mysql> grant super on *.* to 'replica'@'applinux00linux003.richinfo.cn';
Query OK, 0 rows affected (0.00 sec)
mysql> create user 'replica'@'applinux002.richinfo.cn' identified by 'replica';
Query OK, 0 rows affected (0.00 sec)
mysql> grant replication slave on *.* to 'replica'@'applinux002.richinfo.cn';
Query OK, 0 rows affected (0.00 sec)
mysql> grant super on *.* to 'replica'@'applinux00linux002.richinfo.cn';
Query OK, 0 rows affected (0.00 sec)
(4)锁定数据库状态，读取主服务器二进制日志的状态
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 |
+------------------+----------+--------------+------------------+
| mysql-bin.000025 | 1213 | | |
+------------------+----------+--------------+------------------+
1 row in set (0.00 sec)
(5)使用mysqldump创建数据库快照,释放锁
mysql> quit
Bye
[root@applinux002 data]# mysqldump -u root -p --all-database --lock-all-tables > dbdump.db
Enter password:
mysql> unlock tables;
Query OK, 0 rows affected (0.00 sec)
(6)在从服务器上恢复数据：
[root@applinux003 data]# service mysql status
MySQL running (25059) [ OK ]
[root@applinux003 data]# pwd
/md3200i/data1/mysql/data
[root@applinux003 data]# /usr/local/mysql/bin/mysqladmin -u root -p123456 password 'T4GRUkwMtqIpVzgXA3o6'
[root@applinux003 data]# mysql -u root –p < dbdump.db
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 5
………….
(7)用replica用户做互连测试：
Slave库上
[root@applinux003 data]# mysql -h applinux002.richinfo.cn -ureplica -preplica -P8808
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 134
Server version: 5.5.15-log Source distribution
Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql>
(8) slave配置
mysql> stop slave;
Query OK, 0 rows affected, 1 warning (0.00 sec)
mysql> change master to
-> master_host='applinux002.richinfo.cn',
-> master_user='replica',
-> master_password='replica',
-> master_port=8808,
-> master_log_file='mysql-bin.000025',
-> master_log_pos=589 ;
Query OK, 0 rows affected (0.02 sec)
--在配置过程中此处多了一个空格导致无法找到log-bin的索引文件，因此一定要仔细，认真…….
mysql> start slave;
mysql> use itao;
Database changed
mysql> select * from test;
+------+
| id |
+------+
| 1 |
| 2 |
| 810 |
+------+
3 rows in set (0.00 sec)
mysql> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: applinux002.richinfo.cn
Master_User: replica
Master_Port: 8808
Connect_Retry: 60
Master_Log_File: mysql-bin.000025
Read_Master_Log_Pos: 1403
Relay_Log_File: applinux003-relay-bin.000002
Relay_Log_Pos: 443
Relay_Master_Log_File: mysql-bin.000025
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: 1403
Relay_Log_Space: 605
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: 1
1 row in set (0.00 sec)
ERROR:
No query specified
---整个复制过程搭建完毕，
(9)进行mysql AB复制测试
Master：
mysql> use itao;
Database changed
mysql> insert into test(id) values (100);
Query OK, 1 row affected (0.01 sec)
mysql> insert into test(id) values (200);
Query OK, 1 row affected (0.00 sec)
mysql>
Slave：
mysql> use itao;
Database changed
mysql> select * from test;
+------+
| id |
+------+
| 1 |
| 2 |
| 810 |
| 100 |
+------+
4 rows in set (0.00 sec)
mysql> select * from test;
+------+
| id |
+------+
| 1 |
| 2 |
| 810 |
| 100 |
| 200 |
+------+
5 rows in set (0.00 sec)
保持同步，真正实现了读写分离，master库上可以进行读写操作，slave库上用于读操作，可以用于报表，备份，减少了master的压力。
本文出自
http://space.itpub.net/8117479/viewspace-705529