（本文参考地址：http://blog.chinaunix.net/u/8111/showart.php?id=451420）
一、必备软件：
1、LUA
可以去LUA的官方下载：www.lua.org
2、MySQL Proxy
这里有好多二进制版本。
http://mysql.cdpa.nsysu.edu.tw/Downloads/MySQL-Proxy/
或者去MYSQL官方下载源代码。
3、测试过程中取消了B和C的REPLICATION。这样SQL语句一下子就看出来从哪里来的。
如果是M-S（可以先在SLAVE上进行STOP SLAVE）
二、测试主机地址：
1、MySQL Proxy 安装地址：192.168.0.234(简称A)
2、MySQL 服务器地址：192.168.0.235(简称B)/236(简称C)
三、安装体验
如果是按照二进制包安装的，跳过这一步。
1、 LUA的安装
[root@localhost ~]#tar zxvf lua-5.1.2.tar.gz -C /usr/local
[root@localhost ~]# cd /usr/local/
[root@localhost local]# mv lua-5.1 lua
[root@localhost lua]# cd lua
[root@localhost lua]#make local;make install;
导出环境变量：
[root@localhost lua]#export LUA_CFLAGS="-I/usr/local/include" LUA_LIBS="-L/usr/local/lib -llua -ldl" LDFLAGS="-lm"
2、MySQL Proxy 安装
[root@localhost ~]#tar -zxvf mysql-proxy-0.6.1-linux-rhel4-x86-32bit.tar.gz -C /usr/local/mysql/
[root@localhost ~]#cd /usr/local/mysql
[root@localhost mysql]#mv mysql-proxy-0.6.1-linux-rhel4-x86-32bit/ mysql-proxy
[root@localhost sbin]# export PATH=$PATH:/usr/local/mysql/mysql-proxy/sbin/
四、使用MySQL Proxy
1、查看帮助选项
[root@localhost ~]# mysql-proxy --help-all
2、对MySQL 操作
MySQL服务器假设已经安装。(安装步骤这里就不写了)
两台机器上的表初始结构和数据都是一样的，而且都有t_girl_user这个用户。
mysql> desc t;
+-------+----------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------+----------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| c_str | char(64) | NO | | | |
+-------+----------+------+-----+---------+----------------+
2 rows in set (0.00 sec)
2 rows in set (0.00 sec)
我在B上插入一条记录
mysql> insert into t(c_str) values('B');
Query OK, 1 row affected (0.00 sec)
在C上同样插入一条记录
mysql> insert into t(c_str) value('C');
Query OK, 1 row affected (0.00 sec)
mysql>
3、启动MySQL-Proxy（测试读写分离）
[root@localhostsbin]# mysql-proxy--proxy-read-only-backend-addresses=192.168.0.236:3306--proxy-backend-addresses=192.168.0.235:3306 --proxy-lua-script=/usr/local/mysql/mysql-proxy/share/mysql-proxy/rw-splitting.lua&
[1] 32554
让MYSQL PROXY自动启动的简单脚本
#!/bin/sh
# export PATH=$PATH:/usr/local/mysql-proxy
cd /usr/local/mysql-proxy
./mysql-proxy--proxy-read-only-backend-addresses=192.168.0.236:3306--proxy-backend-addresses=192.168.0.235:3306--proxy-lua-script=rw-splitting.lua >> /tmp/log
~
这个例子中限制192.168.0.236为只读,192.168.0.235为可写。
4、下来我们来看试验结果。
我们用几台客户端开启4个连接。
[root@localhost ~]# /usr/local/mysql/bin/mysql -ut_girl_user -p123456 -P4040 -h192.168.0.234 -Dt_girl
我这边已经启动了好几个客户端，这里就不贴了，命令和上面的一样。
写数据。
mysql> insert into t(c_str) values ('wangwang');
Query OK, 1 row affected (0.01 sec)
mysql> show processlist;
+----+-------------+---------------------+--------+---------+------+-------+------------------+
| Id | User | Host | db | Command | Time | State | Info |
+----+-------------+---------------------+--------+---------+------+-------+------------------+
| 12 | t_girl_user | 192.168.0.234:44975 | t_girl | Sleep | 28 | | NULL |
| 13 | t_girl_user | 192.168.0.234:44976 | t_girl | Sleep | 15 | | NULL |
| 14 | t_girl_user | 192.168.0.234:44977 | t_girl | Sleep | 19 | | NULL |
| 15 | t_girl_user | 192.168.0.234:44978 | t_girl | Query | 0 | NULL | show processlist |
+----+-------------+---------------------+--------+---------+------+-------+------------------+
4 rows in set (0.00 sec)
4 rows in set (0.00 sec)
读数据（现在还是写和读都在B上）
mysql> select * from t;
+----+----------+
| id | c_str |
+----+----------+
| 1 | B |
| 2 | wangwang |
+----+----------+
2 rows in set (0.00 sec)
再增加一个客户端连接。
1 row in set (0.00 sec)
mysql> show processlist;
+----+-------------+---------------------+--------+---------+------+-----------------------------------------------------------------------+------------------+
|Id | User | Host | db | Command | Time |State |Info |
+----+-------------+---------------------+--------+---------+------+-----------------------------------------------------------------------+------------------+
| 2 | system user | | NULL | Connect | 1842 | Hasread all relay log; waiting for the slave I/O thread to update it |NULL |
| 5 | root | localhost |t_girl | Query | 0 |NULL |show processlist |
| 12 | t_girl_user | 192.168.0.234:44975 |t_girl | Sleep | 446| | NULL |
| 13 | t_girl_user | 192.168.0.234:44976 |t_girl | Sleep | 188| | NULL |
| 14 | t_girl_user | 192.168.0.234:44977 |t_girl | Sleep | 206| | NULL |
| 15 | t_girl_user | 192.168.0.234:44978 |t_girl | Sleep | 203| | NULL |
| 16 | t_girl_user | 192.168.0.234:44979 |t_girl | Sleep | 164| | NULL |
| 17 | t_girl_user | 192.168.0.234:44980 |t_girl | Sleep | 210| | NULL |
+----+-------------+---------------------+--------+---------+------+-----------------------------------------------------------------------+------------------+
8 rows in set (0.00 sec)
现在我们来读数据。
mysql> select * from t;
+----+-------+
| id | c_str |
+----+-------+
| 1 | C |
+----+-------+
1 row in set (0.00 sec)
这个数据很明显是来自C的。
再插入一条记录
mysql> insert into t(c_str) values ('wangwei');
Query OK, 1 row affected (0.00 sec)
mysql> select * from t;
+----+-------+
| id | c_str |
+----+-------+
| 1 | C |
+----+-------+
1 row in set (0.00 sec)
C上的数据没有变。
还是没有数据。
现在跑到B上看看。
mysql> show processlist;
+----+-------------+---------------------+--------+---------+------+-----------------------------------------------------------------------+------------------+
|Id | User | Host | db | Command | Time |State |Info |
+----+-------------+---------------------+--------+---------+------+-----------------------------------------------------------------------+------------------+
| 2 | system user | | NULL | Connect | 1842 | Hasread all relay log; waiting for the slave I/O thread to update it |NULL |
| 5 | root | localhost | t_girl | Query | 0 |NULL |show processlist |
|12 | t_girl_user | 192.168.0.234:44975 | t_girl | Sleep | 446| | NULL |
|13 | t_girl_user | 192.168.0.234:44976 | t_girl | Sleep | 188| | NULL |
|14 | t_girl_user | 192.168.0.234:44977 | t_girl | Sleep | 206| | NULL |
|15 | t_girl_user | 192.168.0.234:44978 | t_girl | Sleep | 203| | NULL |
|16 | t_girl_user | 192.168.0.234:44979 | t_girl | Sleep | 164| | NULL |
|17 | t_girl_user | 192.168.0.234:44980 | t_girl | Sleep | 210| | NULL |
+----+-------------+---------------------+--------+---------+------+-----------------------------------------------------------------------+------------------+
8 rows in set (0.00 sec)
mysql> select * from t;
+----+----------+
| id | c_str |
+----+----------+
| 1 | B |
| 2 | wangwang |
| 3 | wangwei |
+----+----------+
3 rows in set (0.00 sec)
数据被成功插入到B这个读写分离应该看得很清楚。其他的功能等我测试了再总结吧。
如果要知道为什么连接多了才会进行分离的话，看看
手册
论坛里面的讨论
还有其他我以前收藏的地址，可以参考以下。
http://www.infoq.com/news/2007/10/mysqlproxyrwsplitting;jsessionid=F9E0B91935E82033BAFAC067A326DC4B
http://blogs.mysql.com/kaj/2007/12/10/combining-mysql-proxy-with-mysql-cluster/