实战MySQL主从数据库同步 增强系统安全性_MySQL

试验环境:
主服务器:CentOS 5.2 Mysql 5.1.35 源码 IP:192.168.1.22
从服务器:CentOS 5.2 Mysql 5.1.35 源码 IP:192.168.1.33

配置:

一、主服务器

1.1、创建一个复制用户，具有replication slave 权限。
 

<ol class="dp-xml"><li class="alt"><span><span>mysql</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>grant replication slave on *.* to ‘repl’@’192.168.1.22′ identified by ‘repl’; </span></span></li></ol>

1.2、编辑my.cnf文件
vi /etc/my.cnf
添加
server-id=1
并开启log-bin二进制日志文件
log-bin=mysql-bin
注:需要把默认的server-id=1去掉
1.3、启动mysql数据库
 

<ol class="dp-xml"><li class="alt"><span><span>mysqld_safe –</span><span class="attribute"><font color="#ff0000">user</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">mysql</font></span><span> & </span></span></li></ol>

1.4、设置读锁
 

<ol class="dp-xml"><li class="alt"><span><span>mysql</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>flush tables with read lock; </span></span></li></ol>

1.5、得到binlog日志文件名和偏移量
 

<ol class="dp-xml">
<li class="alt"><span><span>mysql</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>show master status;  </span></span></li>
<li><span>+——————+———-+————–+——————+  </span></li>
<li class="alt"><span>| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |  </span></li>
<li><span>+——————+———-+————–+——————+  </span></li>
<li class="alt"><span>| mysql-bin.0000010 | 106| | |  </span></li>
<li><span>+——————+———-+————–+——————+ </span></li>
</ol>

1.6、备份要同步的数据库
 

<ol class="dp-xml"><li class="alt"><span><span>mysqldump test </span><span class="tag"><strong><font color="#006699">></font></strong></span><span> test.sql </span></span></li></ol>

1.7、解锁
 

<ol class="dp-xml"><li class="alt"><span><span>mysql</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>unlock tables; </span></span></li></ol>

二、从服务器

2.1、编辑my.cnf文件
vi /etc/my.cnf
添加
server-id=2
注:需要把默认的server-id=1去掉
2.2、启动从数据库
 

<ol class="dp-xml"><li class="alt"><span><span>mysqld_safe –</span><span class="attribute"><font color="#ff0000">user</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">mysql</font></span><span> & </span></span></li></ol>

2.3、对从数据库进行相应设置
 

<ol class="dp-xml">
<li class="alt"><span><span>mysql</span><span class="tag"><strong><font color="#006699">></font></strong></span><span> change master to  </span></span></li>
<li>
<span>-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span> </span><span class="attribute"><font color="#ff0000">master_host</font></span><span>=’192.168.1.22′  </span>
</li>
<li class="alt">
<span>-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span> </span><span class="attribute"><font color="#ff0000">master_user</font></span><span>=’repl’  </span>
</li>
<li>
<span>-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span> </span><span class="attribute"><font color="#ff0000">master_password</font></span><span>=’repl’  </span>
</li>
<li class="alt">
<span>-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span> </span><span class="attribute"><font color="#ff0000">master_log_file</font></span><span>=’mysql-bin.0000010′  </span>
</li>
<li>
<span>-</span><span class="tag"><strong><font color="#006699">></font></strong></span><span> </span><span class="attribute"><font color="#ff0000">master_log_pos</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">106</font></span><span>; </span>
</li>
</ol>

2.4、启动从服务器slave线程
 

<ol class="dp-xml"><li class="alt"><span><span>mysql</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>start slave; </span></span></li></ol>

执行show processlist命令显示以下进程:
 

<ol class="dp-xml">
<li class="alt"><span><span>mysql</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>show processlist\G  </span></span></li>
<li><span> </span></li>
<li class="alt"><span>*************************** 2. row ***************************  </span></li>
<li><span>Id: 2  </span></li>
<li class="alt"><span>User: system user  </span></li>
<li><span>Host:  </span></li>
<li class="alt"><span>db: NULL  </span></li>
<li><span>Command: Connect  </span></li>
<li class="alt"><span>Time: 2579  </span></li>
<li><span>State: Has read all relay log; waiting for the slave I/O thread to update it </span></li>
</ol>

Info: NULL表示slave已经连接上master，开始接受并执行日志
2.5、查看slave线程状态
 

<ol class="dp-xml">
<li class="alt"><span><span>mysql</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>show slave status;  </span></span></li>
<li><span>*************************** 1. row ***************************  </span></li>
<li class="alt"><span>Slave_IO_State: Waiting for master to send event  </span></li>
<li><span>Master_Host: 192.168.1.22  </span></li>
<li class="alt"><span>Master_User: repl  </span></li>
<li><span>Master_Port: 3306  </span></li>
<li class="alt"><span>Connect_Retry: 60  </span></li>
<li><span>Master_Log_File: mysql-bin.0000010  </span></li>
<li class="alt"><span>Read_Master_Log_Pos: 106  </span></li>
<li><span>Relay_Log_File: centos-relay-bin.000002  </span></li>
<li class="alt"><span>Relay_Log_Pos: 529  </span></li>
<li><span>Relay_Master_Log_File: mysql-bin.0000010  </span></li>
<li class="alt"><span>Slave_IO_Running: Yes  </span></li>
<li><span>Slave_SQL_Running: Yes  </span></li>
<li class="alt"><span>Replicate_Do_DB:  </span></li>
<li><span>Replicate_Ignore_DB:  </span></li>
<li class="alt"><span>Replicate_Do_Table:  </span></li>
<li><span>Replicate_Ignore_Table:  </span></li>
<li class="alt"><span>Replicate_Wild_Do_Table:  </span></li>
<li><span>Replicate_Wild_Ignore_Table:  </span></li>
<li class="alt"><span>Last_Errno: 0  </span></li>
<li><span>Last_Error:  </span></li>
<li class="alt"><span>Skip_Counter: 0  </span></li>
<li><span>Exec_Master_Log_Pos: 106  </span></li>
<li class="alt"><span>Relay_Log_Space: 830  </span></li>
<li><span>Until_Condition: None  </span></li>
<li class="alt"><span>Until_Log_File:  </span></li>
<li><span>Until_Log_Pos: 0  </span></li>
<li class="alt"><span>Master_SSL_Allowed: No  </span></li>
<li><span>Master_SSL_CA_File:  </span></li>
<li class="alt"><span>Master_SSL_CA_Path:  </span></li>
<li><span>Master_SSL_Cert:  </span></li>
<li class="alt"><span>Master_SSL_Cipher:  </span></li>
<li><span>Master_SSL_Key:  </span></li>
<li class="alt"><span>Seconds_Behind_Master: 0  </span></li>
<li><span>Master_SSL_Verify_Server_Cert: No  </span></li>
<li class="alt"><span>Last_IO_Errno: 0  </span></li>
<li><span>Last_IO_Error:  </span></li>
<li class="alt"><span>Last_SQL_Errno: 0  </span></li>
<li><span>Last_SQL_Error:  </span></li>
<li class="alt"><span>1 row in set (0.00 sec) </span></li>
</ol>

 

验证是否配置正确
在从服务器上执行
 

<ol class="dp-xml">
<li class="alt"><span><span>show slave status\G;  </span></span></li>
<li><span>Waiting for master to send event  </span></li>
<li class="alt"><span>Slave_IO_Running: Yes  </span></li>
<li><span>Slave_SQL_Running: Yes </span></li>
</ol>

如以上二行同时为Yes 说明配置成功

测试：

1、在主服务器test数据库中创建user表
 

<ol class="dp-xml">
<li class="alt"><span><span>mysql</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>use test;  </span></span></li>
<li>
<span>mysql</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>create table user(id int); </span>
</li>
</ol>

2、在从服务器中查看user表
 

<ol class="dp-xml">
<li class="alt"><span><span>mysql</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>use test;  </span></span></li>
<li>
<span>mysql</span><span class="tag"><strong><font color="#006699">></font></strong></span><span> show tables like ‘user’;  </span>
</li>
<li class="alt"><span>+———————-+  </span></li>
<li><span>| Tables_in_test(user) |  </span></li>
<li class="alt"><span>+———————-+  </span></li>
<li><span>| user |  </span></li>
<li class="alt"><span>+———————-+  </span></li>
<li><span>1 row in set (0.00 sec) </span></li>
</ol>

说明主从数据同步成功。

常见问题归纳：

1.在从数据库中查看slave状态时出现
The slave I/O thread stops because master and slave have equal MySQL server ids; these ids must be different for replication to work (or the –replicate-same-server-id option must be used on slave but this does not always make sense; please check the manual before using it)
说明方从服务器里my.cnf中的server-id有相同的。
解决办法:
修改my.cnf里的server-id，并重启数据库服务。my.cnf文件默认有server-id=1

其它说明
主服务器my.cnf
#binlog-do-db=需要备份的数据库名，可写多行
#binlog-ignore-db=不需要备份的数据库名，可写多行
从服务器my.cnf
# replicate-do-db=test 需要备份的数据库名
# replicate-ignore-db=mysql 忽略的数据库
# master-connect-retry=60 如果从服务器发现主服务器断掉，重新连接的时间差(秒)
以下设置也可直接修改my.cnf配置文件
 

<ol class="dp-xml">
<li class="alt"><span><span class="attribute"><font color="#ff0000">log-bin</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">mysql</font></span><span>-bin  </span></span></li>
<li>
<span class="attribute"><font color="#ff0000">master-host</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">192</font></span><span>.168.1.22  </span>
</li>
<li class="alt">
<span class="attribute"><font color="#ff0000">master-user</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">repl</font></span><span> </span>
</li>
<li>
<span class="attribute"><font color="#ff0000">master-password</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">repl</font></span><span> </span>
</li>
<li class="alt">
<span class="attribute"><font color="#ff0000">master-port</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">3306</font></span><span> </span>
</li>
</ol>

主从服务器同步维护
由于各种原因，导致主从数据不一致，在负载低的时候，进行手动同步.
在主服务器上执行

<ol class="dp-xml">
<li class="alt"><span><span>mysql</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>flush tables with read lock;  </span></span></li>
<li><span>Query OK,rows affected (0.01 sec)  </span></li>
<li class="alt">
<span>mysql</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>show master status;  </span>
</li>
<li><span>+——————+———-+————–+——————+  </span></li>
<li class="alt"><span>| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |  </span></li>
<li><span>+——————+———-+————–+——————+  </span></li>
<li class="alt"><span>| mysql-bin.0000011 | 260| | |  </span></li>
<li><span>+——————+———-+————–+——————+ </span></li>
</ol>

在从服务器上执行
先得到当前主服务器的二进制文件名和偏移量,执行命令使从服务器与主服务器同步
 

<ol class="dp-xml">
<li class="alt"><span><span>mysql</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>select master_pos_wait(‘mysql-bin.0000011′,’260′);  </span></span></li>
<li><span>+————————————————–+  </span></li>
<li class="alt"><span>| master_pos_wait(‘mysql-bin.0000011′,’260′) |  </span></li>
<li><span>+————————————————–+  </span></li>
<li class="alt"><span>| 0 |  </span></li>
<li><span>+————————————————–+  </span></li>
<li class="alt"><span>1 row in set (0.01 sec) </span></li>
</ol>

同步完成后，在主服务器上执行解锁
 

<ol class="dp-xml"><li class="alt"><span><span>mysql</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>unlock tables; </span></span></li></ol>

切换主从服务器

当主服务器出现故障时，可将从服务器当主服务器来使用.步骤如下:
1、保证所有从数据库都已经执行了relay log中的全部更新，在从服务器中执行
stop slave io_thread,用show processlist检查，查看状态是否是Has read all relay log,表示更新完成.
 

<ol class="dp-xml">
<li class="alt"><span><span>mysql</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>stop slave io_thread;  </span></span></li>
<li><span>Query OK,0 affected (0.00 sec)  </span></li>
<li class="alt">
<span>mysql</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>show processlist\G;  </span>
</li>
<li><span>*************************** 2. row ***************************  </span></li>
<li class="alt"><span>Id: 2  </span></li>
<li><span>User: system user  </span></li>
<li class="alt"><span>Host:  </span></li>
<li><span>db: NULL  </span></li>
<li class="alt"><span>Command: Connect  </span></li>
<li><span>Time: 4757  </span></li>
<li class="alt"><span>State: Has read all relay log; waiting for the slave I/O thread to update it  </span></li>
<li><span>Info: NULL </span></li>
</ol>

2、在从服务器上执行stop slave，reset master命令，重置成主数据库
 

<ol class="dp-xml">
<li class="alt"><span><span>mysql</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>stop slave;  </span></span></li>
<li><span>Query OK,0 affected (0.00 sec)  </span></li>
<li class="alt">
<span>mysql</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>reset master;  </span>
</li>
<li><span>Query OK,0 affected (0.00 sec) </span></li>
</ol>

3、删除新的主服务器数据库目录中的master.info和relay-log.info文件，否则下次重启时还会按照从服务器来启动.