MySQL（十六）之使用Mysql-Proxy实现MySQL的读写分离

wiuyiyi

一、Mysql-Proxy 简单介绍
   MySQL-Proxy是一个处于你的client端和MySQL server端之间的简单程序，它可以监测、分析或改变它们的通信。它使用灵活，没有限制，常见的用途包括：负载平衡，故障、查询分析，查询过滤和修改等等。
   MySQL-Proxy就是这么一个中间层代理，简单的说，MySQL-Proxy就是一个连接池，负责将前台应用的连接请求转发给后台的数据库，并且通过使用lua脚本，可以实现复杂的连接控制和过滤，从而实现读写分离和负载平衡。对于应用来说，MySQL-Proxy是完全透明的，应用则只需要连接到MySQL-Proxy的监听端口即可。当然，这样proxy机器可能成为单点失效，但完全可以使用多个proxy机器做为冗余，在应用服务器的连接池配置中配置到多个proxy的连接参数即可。
   MySQL-Proxy更强大的一项功能是实现“读写分离”，基本原理是让主数据库处理事务性查询，让从库处理SELECT查询。数据库复制被用来把事务性查询导致的变更同步到集群中的从库。

二、环境介绍
1、实验拓扑

2、环境介绍

3、时间同步

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[iyunv@proxy ~]# ntpdate 202.120.2.101 [iyunv@master ~]# ntpdate 202.120.2.101 [iyunv@slave ~]# ntpdate 202.120.2.101

三、Mysql-Proxy 命令简介

• --help-all ———— 用于获取全部帮助信息
  
• --proxy-address=host:port ———— 代理服务监听的地址和端口
  
• --admin-address=host:port ———— 管理模块监听的地址和端口
  
• --proxy-backend-addresses=host:port ———— 后端mysql服务器的地址和端口（主服务器）
  
• --proxy-read-only-backend-addresses=host:port ———— 后端只读mysql服务器的地址和端口（从服务器）
  
• --proxy-lua-script=file ———— 完成mysql代理功能的Lua脚本
  
• --daemon ———— 以守护进程模式启动mysql-proxy
  
• --defaults-file=/path/to/conf_file_name ： 默认使用的配置文件路径
  
• --log-file=/path/to/log_file_name： 日志文件名称
  
• --log-level=level ：日志级别
  
• --log-use-syslog：基于syslog记录日志
  
• --user=user_name： 运行mysql-proxy进程的用户
  
  

四、配置Mysql-Proxy主从分离
   声明：在在做Mysql-Proxy主从分离时由于自己的虚拟机已经还原，故一直没有想到我的主从还没有先搭建主从同步环境，于是一直按别人的实验走下去，到最后发现别人的结果相差太远，故浪费了不少时间，这里说明在做此实验时一定要现将你的主从复制做好，在接下来做这个实验。
1、增加代理用户

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[iyunv@proxy ~]# groupadd mysql-proxy [iyunv@proxy ~]# useradd -g mysql-proxy -s /sbin//nologin -M mysql-proxy [iyunv@proxy ~]# id mysql-proxy uid=1002(mysql-proxy) gid=1002(mysql-proxy) 组=1002(mysql-proxy)

2、安装mysql-proxy

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[iyunv@proxy src]# wget http://mirrors.sohu.com/mysql/My ... .3-x86-64bit.tar.gz [iyunv@proxy src]# tar -xf mysql-proxy-0.8.4-linux-glibc2.3-x86-64bit.tar.gz -C /usr/local/ [iyunv@proxy src]# cd /usr/local/ [iyunv@proxy local]# ln -sv mysql-proxy-0.8.4-linux-glibc2.3-x86-64bit mysql-proxy "mysql-proxy" -> "mysql-proxy-0.8.4-linux-glibc2.3-x86-64bit" [iyunv@proxy local]# cd mysql-proxy [iyunv@proxy mysql-proxy]# chown -R mysql-proxy.mysql-proxy /usr/local/mysql-proxy/* [iyunv@proxy mysql-proxy]# ll 总用量 24 drwxr-xr-x 2 mysql-proxy mysql-proxy 4096 12月 24 2013 bin drwxr-xr-x 2 mysql-proxy mysql-proxy 4096 12月 24 2013 include drwxr-xr-x 6 mysql-proxy mysql-proxy 4096 12月 24 2013 lib drwxr-xr-x 2 mysql-proxy mysql-proxy 4096 12月 24 2013 libexec drwxr-xr-x 8 mysql-proxy mysql-proxy 4096 12月 24 2013 licenses drwxr-xr-x 3 mysql-proxy mysql-proxy 4096 12月 24 2013 share

3、配置环境变量

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[iyunv@proxy ~]# vim /etc/profile.d/mysql-proxy.sh export PATH=$PATH:/usr/local/mysql-proxy/bin [iyunv@proxy ~]# source /etc/profile.d/mysql-proxy.sh

4、配置sysV脚本

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[iyunv@proxy ~]# vim /etc/init.d/mysql-proxy #!/bin/bash # # mysql-proxy This script starts and stops the mysql-proxy daemon # # chkconfig: - 78 30 # processname: mysql-proxy # description: mysql-proxy is a proxy daemon for mysql # Source function library. . /etc/rc.d/init.d/functions prog="/usr/local/mysql-proxy/bin/mysql-proxy" # Source networking configuration. if [ -f /etc/sysconfig/network ]; then     . /etc/sysconfig/network fi # Check that networking is up. [ ${NETWORKING} = "no" ] && exit 0 # Set default mysql-proxy configuration. ADMIN_USER="admin" ADMIN_PASSWD="admin" ADMIN_LUA_SCRIPT="/usr/local/mysql-proxy/share/doc/mysql-proxy/admin.lua" PROXY_OPTIONS="--daemon" PROXY_PID=/var/run/mysql-proxy.pid PROXY_USER="mysql-proxy" # Source mysql-proxy configuration. if [ -f /etc/sysconfig/mysql-proxy ]; then     . /etc/sysconfig/mysql-proxy fi RETVAL=0 start() {     echo -n $"Starting $prog: "     daemon $prog $PROXY_OPTIONS --pid-file=$PROXY_PID --proxy-address="$PROXY_ADDRESS" --user=$PROXY_USER --admin-username="$ADMIN_USER" --admin-lua-script="$ADMIN_LUA_SCRIPT" --admin-password="$ADMIN_PASSWORD"     RETVAL=$?     echo     if [ $RETVAL -eq 0 ]; then         touch /var/lock/subsys/mysql-proxy     fi } stop() {     echo -n $"Stopping $prog: "     killproc -p $PROXY_PID -d 3 $prog     RETVAL=$?     echo     if [ $RETVAL -eq 0 ]; then         rm -f /var/lock/subsys/mysql-proxy         rm -f $PROXY_PID     fi } # See how we were called. case "$1" in     start)         start         ;;     stop)         stop         ;;     restart)         stop         start         ;;     condrestart|try-restart)         if status -p $PROXY_PIDFILE $prog >&/dev/null; then             stop             start         fi         ;;     status)         status -p $PROXY_PID $prog         ;;     *)         echo "Usage: $0 {start|stop|restart|reload|status|condrestart|try-restart}"         RETVAL=1         ;; esac exit $RETVAL [iyunv@proxy ~]# chmod +x /etc/init.d/mysql-proxy [iyunv@proxy ~]# chkconfig --add mysql-proxy

5、为服务脚本提供配置文件

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[iyunv@proxy ~]# vim /etc/sysconfig/mysql-proxy # Options for mysql-proxy ADMIN_USER="admin" ADMIN_PASSWORD="admin" ADMIN_ADDRESS="" ADMIN_LUA_SCRIPT="/usr/local/mysql-proxy/share/doc/mysql-proxy/admin.lua" PROXY_ADDRESS="0.0.0.0:3306" PROXY_USER="mysql-proxy" PROXY_OPTIONS="--daemon --log-level=info --log-file="/var/log/mysql-proxy.log" --plugins=proxy --plugins=admin --proxy-backend-addresses=192.168.1.8:3306 --proxy-read-only-backend-addresses=192.168.1.10:3306 --proxy-lua-script=/usr/local/mysql-proxy/share/doc/mysql-proxy/rw-splitting.lua"

   注意：其中的proxy-backend-addresses选项和proxy-read-only-backend-addresses选项均可重复使用多次，以实现指定多个读写服务器或只读服务器。

6、建立admin.lua脚本

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[iyunv@proxy mysql-proxy]# cat /usr/local/mysql-proxy/share/doc/mysql-proxy/admin.lua --[[ $%BEGINLICENSE%$ Copyright (c) 2007, 2012, Oracle and/or its affiliates. All rights reserved. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA $%ENDLICENSE%$ --]] function set_error(errmsg) proxy.response = {   type = proxy.MYSQLD_PACKET_ERR,   errmsg = errmsg or "error" } end function read_query(packet) if packet:byte() ~= proxy.COM_QUERY then   set_error("[admin] we only handle text-based queries (COM_QUERY)")   return proxy.PROXY_SEND_RESULT end local query = packet:sub(2) local rows = { } local fields = { } if query:lower() == "select * from backends" then   fields = {    { name = "backend_ndx",      type = proxy.MYSQL_TYPE_LONG },    { name = "address",      type = proxy.MYSQL_TYPE_STRING },    { name = "state",      type = proxy.MYSQL_TYPE_STRING },    { name = "type",      type = proxy.MYSQL_TYPE_STRING },    { name = "uuid",      type = proxy.MYSQL_TYPE_STRING },    { name = "connected_clients",      type = proxy.MYSQL_TYPE_LONG },   }   for i = 1, #proxy.global.backends do    local states = {     "unknown",     "up",     "down"    }    local types = {     "unknown",     "rw",     "ro"    }    local b = proxy.global.backends    rows[#rows + 1] = {     i,     b.dst.name,          -- configured backend address     states[b.state + 1], -- the C-id is pushed down starting at 0     types[b.type + 1],   -- the C-id is pushed down starting at 0     b.uuid,              -- the MySQL Server's UUID if it is managed     b.connected_clients  -- currently connected clients    }   end elseif query:lower() == "select * from help" then   fields = {    { name = "command",      type = proxy.MYSQL_TYPE_STRING },    { name = "description",      type = proxy.MYSQL_TYPE_STRING },   }   rows[#rows + 1] = { "SELECT * FROM help", "shows this help" }   rows[#rows + 1] = { "SELECT * FROM backends", "lists the backends and their state" } else   set_error("use 'SELECT * FROM help' to see the supported commands")   return proxy.PROXY_SEND_RESULT end proxy.response = {   type = proxy.MYSQLD_PACKET_OK,   resultset = {    fields = fields,    rows = rows   } } return proxy.PROXY_SEND_RESULT [iyunv@proxy mysql-proxy]# /etc/init.d/mysql-proxy start 正在启动 /usr/local/mysql-proxy/bin/mysql-proxy：     [确定] [iyunv@proxy mysql-proxy]# ss -tunlp | grep mysql-proxy tcp    LISTEN     0      128                    *:4041                  *:*      users:(("mysql-proxy",2692,11)) tcp    LISTEN     0      128                    *:3306                  *:*      users:(("mysql-proxy",2692,10))

7、在主服务器上创建测试的账号与密码

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MariaDB [(none)]> grant all on *.* to 'admin'@'192.168.%.%' identified by 'admin'; Query OK, 0 rows affected (0.00 sec) MariaDB [(none)]> flush privileges; Query OK, 0 rows affected (0.00 sec)

8、测试
注意你的proxy主机没有启动mysql，proxy的主要作用就是通过其能做到反向代理的功能实现读写分离。

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[iyunv@proxy mysql-proxy]# mysql ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2 "No such file or directory") [iyunv@proxy mysql-proxy]# mysql -uadmin -padmin -h192.168.1.9 Welcome to the MariaDB monitor.  Commands end with ; or \g. Your MariaDB connection id is 8 Server version: 10.0.21-MariaDB-log Source distribution Copyright (c) 2000, 2015, Oracle, MariaDB Corporation Ab and others. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. MariaDB [(none)]> show databases; +---------------------+ | Database            | +---------------------+ | #mysql50#lost+found | | information_schema  | | mysql               | | performance_schema  | | test                | | testdb              | +---------------------+ 6 rows in set (0.00 sec) MariaDB [(none)]> use testdb Database changed MariaDB [testdb]> create table tt (name char(20)); Query OK, 0 rows affected (0.10 sec) MariaDB [testdb]> insert into tt values('bols'),('longls'); Query OK, 2 rows affected (0.08 sec) Records: 2  Duplicates: 0  Warnings: 0 MariaDB [testdb]> select * from tt; +--------+ | name   | +--------+ | bols   | | longls | +--------+ 2 rows in set (0.00 sec)

在主上能查看到在proxy上写入的数据：

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MariaDB [(none)]> select * from testdb.tt; +--------+ | name   | +--------+ | bols   | | longls | +--------+ 2 rows in set (0.00 sec)

在从上也能查看到在proxy上写入的数据：

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MariaDB [(none)]> select * from testdb.tt; +--------+ | name   | +--------+ | bols   | | longls | +--------+ 2 rows in set (0.00 sec)

通过连接proxy的管理接口就能看到其管理的机器，由于实验中读的数据量较少，故在从上的只读功能没有体现出来。

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[iyunv@proxy mydata]# mysql -uadmin -padmin -h192.168.1.9 --port=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, 2015, 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 | 192.168.1.8:3306  | up    | rw   | NULL |                 0 | |           2 | 192.168.1.10:3306 | up    | ro   | NULL |                 0 | +-------------+-------------------+-------+------+------+-------------------+ 2 rows in set (0.00 sec)