mysql-proxy实现读写分离：
一：mysql主从数据库的配置
要求：配置主
从复制： server2 主 172.25.28.2
server3 从 172.25.28.3
二：安装配置mysql-proxy
[root@server1 /]# tar zxf mysql-proxy-0.8.5-linux-el6-x86-64bit -C /usr/local/[root@server1 local]# ln -s mysql-proxy-0.8.5-linux-el6-x86-64bit/ mysql-proxy ##简化路径
[root@server1 local]# mkdir /usr/local/mysql-proxy/conf
[root@server1 local]# mkdir /usr/local/mysql-proxy/log[root@server1 local]# vim mysql-proxy/conf/mysql-proxy.conf ##编译配置文件
[mysql-proxy]
daemon=true #打入后台
user=root #
keepalive=true
plugins=proxy,admin
log-level=info #日志级别
log-file=/usr/local/mysql-proxy/log/mysql-proxy.log ##proxy日志地址
proxy-address=172.25.28.1:3306 #本机ip地址
proxy-backend-addresses=172.25.28.2:3306 ##backend主 注意addresses
proxy-read-only-backend-addresses=172.25.28.3:3306 ##backend从
proxy-lua-script=/usr/local/mysql-proxy/share/doc/mysql-proxy/rw-splitting.lua ##lua脚本地址
admin-address=172.25.28.1:4041 ##proxy的管理用户adminiphe端口
admin-username=admin
admin-password=westos
admin-lua-script=/usr/local/mysql-proxy/lib/mysql-proxy/lua/admin.lua #admin的lua脚本地址；
更改lua脚本
[root@server1 local]# vim /usr/local/mysql-proxy/share/doc/mysql-proxy/rw-splitting.lua
使其快速进入读写分离状态
-- connection pool
if not proxy.global.config.rwsplit then
proxy.global.config.rwsplit = {
min_idle_connections = 1, ##最小连接数
max_idle_connections = 2, ##最大连接数后实现读写分离
is_debug = false
}
开启proxy控制
[root@server1 local]# /usr/local/mysql-proxy/bin/mysql-proxy --defaults-file=/usr/local/mysql-proxy/conf/mysql-proxy.conf
查看日志状态：
[root@server1 mysql-proxy]# /usr/local/mysql-proxy/bin/mysql-proxy --defaults-file=/usr/local/mysql-proxy/conf/mysql-proxy.conf
[root@server1 mysql-proxy]#cat log/mysql-proxy.log
2017-10-21 13:15:54: (message) chassis-unix-daemon.c:136: [angel] we try to keep PID=1409 alive
2017-10-21 13:15:54: (critical) plugin proxy 0.8.5 started
2017-10-21 13:15:54: (critical) plugin admin 0.8.5 started
2017-10-21 13:15:54: (critical) network-socket.c:492: bind(172.25.28.1:3306) failed: Address already in use (98)
2017-10-21 13:15:54: (critical) chassis-mainloop.c:270: applying config of plugin proxy failed
2017-10-21 13:15:54: (critical) mysql-proxy-cli.c:599: Failure from chassis_mainloop. Shutting down.
2017-10-21 13:15:54: (message) Initiating shutdown, requested from mysql-proxy-cli.c:600
2017-10-21 13:15:54: (message) shutting down normally, exit code is: 1
2017-10-21 13:15:54: (critical) chassis-unix-daemon.c:189: [angel] PID=1380 died on signal=11 (it used 2 kBytes max) ... waiting 3min before restart
2017-10-21 13:15:54: (message) chassis-unix-daemon.c:176: [angel] PID=1409 exited normally with exit-code = 1 (it used 1 kBytes max)
2017-10-21 13:15:54: (message) Initiating shutdown, requested from mysql-proxy-cli.c:273
2017-10-21 13:15:54: (message) shutting down normally, exit code is: 1
2017-10-21 13:15:56: (message) chassis-unix-daemon.c:136: [angel] we try to keep PID=1410 alive
2017-10-21 13:15:56: (critical) plugin proxy 0.8.5 started
2017-10-21 13:15:56: (critical) plugin admin 0.8.5 started
2017-10-21 13:15:56: (message) proxy listening on port 172.25.28.1:3306
2017-10-21 13:15:56: (message) added read/write backend: 172.25.28.2:3306
2017-10-21 13:15:56: (message) added read-only backend: 172.25.28.3:3306
2017-10-21 13:15:56: (message) admin-server listening on port 172.25.28.1:4041
[root@server1 mysql-proxy]#
根据日志可以查看已经控制到mysql
过滤端口：
[root@server1 mysql-proxy]# netstat -anltp
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 936/sshd
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 1012/master
tcp 0 0 172.25.28.1:4041 0.0.0.0:* LISTEN 1410/mysql-proxy
tcp 0 0 172.25.28.1:3306 0.0.0.0:* LISTEN 1410/mysql-proxy
tcp 0 0 172.25.28.1:53135 172.25.28.2:3306 TIME_WAIT -
tcp 0 0 172.25.28.1:22 172.25.28.250:55476 ESTABLISHED 1072/sshd
tcp 0 0 172.25.28.1:53137 172.25.28.2:3306 TIME_WAIT -
tcp 0 0 :::22 :::* LISTEN 936/sshd
tcp 0 0 ::1:25 :::* LISTEN 1012/master
z在master（server1）端给zpy用户权限：
mysql> grant all on test.* to zpy@'%' identified by 'zpy';
Query OK, 0 rows affected (0.00 sec)
下来我们开始检测：
在mysql安装lsof：
[root@server2 ~]# yum install -y lsof
重新开一台设备：
[root@foundation28 mysql10.21]# mysql -h 172.25.28.1 -u zpy -p ##通过访问proxy，直接转到mysql
Enter password:
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 5.1.71-log Source distribution
Copyright (c) 2000, 2016, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
如上每登陆一次，使用lsof观察3306 端口，连接一次
[root@server2 ~]# lsof -i :3306
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
mysqld 1411 mysql 11u IPv4 9514 0t0 TCP *:mysql (LISTEN)
mysqld 1411 mysql 31u IPv4 10201 0t0 TCP 172.25.28.2:mysql->172.25.28.1:53132 (ESTABLISHED)
当连接数大于2（lua脚本中设置的时）；即启动了读写分离机制：
我们可以登陆admin p’roxy管理用户查看：
[root@foundation28 mysql10.21]# mysql -h 172.25.28.1 -u admin -pwestos -P 4041;
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.0.99-agent-admin
Copyright (c) 2000, 2016, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
MySQL [(none)]> select * from backends;
+-------------+------------------+---------+------+------+-------------------+
| backend_ndx | address | state | type | uuid | connected_clients |
+-------------+------------------+---------+------+------+-------------------+
| 1 | 172.25.28.2:3306 | up | rw | NULL | 0 |
| 2 | 172.25.28.3:3306 | unknown | ro | NULL | 0 |
+-------------+------------------+---------+------+------+-------------------+
2 rows in set (0.00 sec)
MySQL [(none)]> Bye
[root@foundation28 mysql10.21]#
当然我们也可以使用上一篇所用的关闭I/O线程，然后写入数据最后在两端查看不同；；