mysql 实现数据同步
用于工作需要  今天研究了下mysql 的主从数据同步
master :
mysql: 5.0.26-community-nt-log
ip :192.168.4.100
slave:
mysql:5.5.19
ip:192.168.17.129


master
在my.cnf 中的

[mysqld]
log-bin =var/mysql/log/mysql-bin.log
server-id=1
binlog-do-db=test //需要同步的库
binlog-do-db=siteschool
binlog-ignore-db=mysql//不需要同步的库
//在master上设置binlog-ignore-db对减少网络带宽，减少replicate lag是有好处的。
执行sql
建立同步的账号
mysql> GRANT REPLICATION SLAVE ON *.* TO 'slave001'@'192.168.17.129' IDENTIFIED BY
'123456';

mysql>  show master status\G;
*************************** 1. row ***************************
            File: mysql-bin.000001
        Position: 6908
    Binlog_Do_DB: test,siteschool
Binlog_Ignore_DB: mysql
1 row in set (0.00 sec)
Query OK, 0 rows affected (0.13 sec)

mysql> flush tables with read lock;
dump  对应的表后 待slave 建好后执行下面的
mysql> unlock tables;

slave 中
修改 /etc/my.cnf

[mysqld]
server-id=2
replicate-do-db=test 要同步的库
read-only=1 
slave-net-timeout=10 
relay-log-index = /data/mysql/relaylog/relaylog
relay-log-info-file = /data/mysql/relaylog/relaylog
relay-log = /data/mysql/relaylog/relaylog

如果 /data/mysql/relaylog 目录不存在 则需要创建，并赋给 mysql 用户 读写权限 不然在
start slave 的时候 会报 error:13d的权限错误

[root@localhost relaylog]# /etc/init.d/mysql  restart

mysql 5.5 以后貌似不能支持直接在 my.cnf  里面修改master 相关的参数 
采用如下sql  执行 
mysql> change master  to  master_user='slave001';  
mysql> change master  to  master_password='123456'; 

此处需要和show master status\G; 对应
mysql> change master  to  master_log_file='mysql-bin.000001';
mysql> change master  to  master_log_pos='6908'; 
 mysql> start slave; 
mysql> show slave  status\G;                                 
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.4.100
                  Master_User: slave001
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000001
          Read_Master_Log_Pos: 6908
               Relay_Log_File: relaylog.000657
                Relay_Log_Pos: 244
        Relay_Master_Log_File: mysql-bin.000001
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
              Replicate_Do_DB: test
          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: 6908
              Relay_Log_Space: 530
              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 (0.03 sec)

正常 OK  

更新test 表中的数据时 二进制文件在变化有 6908-----7478
如果在建立slave 的时候 master Position 发送变化 
需要reset slave  后从新  按照上面的方法 重建 
[root@localhost relaylog]# cat  relaylog
/data/mysql/relaylog/relaylog.000679
814
mysql-bin.000001
7478




二进制的文件为的位置为 6908  一致