哈，原来手里有一份教程， 每次做同步都照做，一直很顺利。这次很久没做同步了，竟然不会了。折腾了好久，特地做个笔记。

Mysql 同步笔记
1.a为主，b为从.
a的ip:10.62.240.128
b的ip:10.62.240.126

a,b 两台机器均装好Mysql,同时确保配置文件中
character_set_server = utf8
collation_server = utf8_unicode_ci
两台机器的设置相同。

2.在主(a)上配置:
[/etc/my.cnf]中mysqld域新增:
log-bin
server-id = 1
sql-bin-update-same
binlog-do-db = database_name
3.在从机器中配置:
master-host=10.62.240.128 #a的ip
master-user=replication
master-password=replication
master-port=3306
server-id=2
master-connect-retry=60
replicate-do-db=database_name
log-slave-updates
4.授权:在a上面进入mysql:
GRANT REPLICATION SLAVE ON *.* TO ‘replication’@'10.62.240.126′ IDENTIFIED BY ‘replication’;
flush privileges;
5.锁定a:
mysql> use database_name;
mysql>FLUSH TABLES WITH READ LOCK; #锁定要同步的test表，然后导出数据结构
mysql>show master status;#记录这里的结果。记录如下:
mysqld-bin.000003 | 1399444 | reping |
mysqldump database_name > dump.sql
mysql> UNLOCK TABLES; #已做好同步数据库结构导出后，解锁这个表

6.在b(从)中载入sql:
mysql -uroot < dump.sql
7:在b中对replication位置进行设定:
mysql>change master to master_host=’10.62.240.128′, master_port=3306, master_user=’replication’,master_password=’replication’,master_log_file=’mysqld-bin.000003′, MASTER_LOG_POS=1399444;

mysql>start slave;#启动复制服务
8:检查主和从之间的同步是否已经跟上:
在a中运行mysql>show master status;
mysql> show master status;
+——————-+———-+————–+——————+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+——————-+———-+————–+——————+
| mysqld-bin.000003 | 5614301 | reping |
再在从中运行msyql> show slave status;
show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 10.62.240.128
Master_User: replication
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysqld-bin.000003
Read_Master_Log_Pos: 5614301
Relay_Log_File: mysqld-relay-bin.000001
Relay_Log_Pos: 4214905
Relay_Master_Log_File: mysqld-bin.000003
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: 5614301
Relay_Log_Space: 4214905
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
1 row in set (0.01 sec)

注意read_master_log_pos也是5614301,说明复制成功。
以后复制出问题时，也是用这种方式查看和修改。那种查入一条记录然后看从库中是不是也执行了的办法，不可取。