使用mysql-proxy实现mysql的读写分离
前言：
MySQL读写分离是指让master处理写操作，让slave处理读操作，非常适用于读操作量比较大的场景，可减轻master的压力。使用mysql-proxy实现mysql的读写分离，mysql-proxy实际上是作为后端mysql主从服务器的代理，它直接接受客户端的请求，对SQL语句进行分析，判断出是读操作还是写操作，然后分发至对应的mysql服务器上。mysql-proxy是官方提供的mysql中间件产品可以实现负载平衡，读写分离，failover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。
实验系统：CentOS 6.6_x86_64
实验前提：防火墙和selinux都关闭
实验说明：本实验共有4台主机，IP分配如拓扑
实验软件：mariadb-10.0.20 mysql-proxy-0.8.5-linux-el6-x86-64bit
下载地址：http://pan.baidu.com/s/1i3F5Pop
实验拓扑：
一、准备工作：
1.将主机名称改为如下所示：
2.将hosts文件添加如下内容：
3.master、slave1和slave2安装mariadb：
tar xf mariadb-10.0.20-linux-x86_64.tar.gz -C /usr/local/ cd /usr/local/ ln -sv mariadb-10.0.20-linux-x86_64 mysql useradd -r mysql mkdir -pv /mydata/data chown -R mysql.mysql /mydata/data/ cd mysql/ chown -R root.mysql . scripts/mysql_install_db --user=mysql --datadir=/mydata/data/ cp support-files/my-large.cnf /etc/my.cnf cp support-files/mysql.server /etc/init.d/mysqld chkconfig --add mysqld chkconfig mysqld on
二、配置主从复制
1.master上配置my.cnf：
[mysqld] server-id = 1 datadir = /mydata/data log-bin = /mydata/data/master-bin binlog_format = ROW sync_binlog = 1 //确保每次事务提交之前都能将二进制日志同步磁盘上
2.slave1上配置my.cnf：
[mysqld] #log-bin=mysql-bin #binlog_format=mixed server-id = 2 datadir = /mydata/data relay_log = /mydata/data/relay-log read_only = 1 sync_master_info = 1 //及时同步master文件 sync_relay_log = 1 //及时同步relay-log文件 sync_relay_log_info = 1 //及时同步relay-log-info文件
3.slave2上配置my.cnf：
[mysqld] #log-bin=mysql-bin #binlog_format=mixed server-id = 3 datadir = /mydata/data relay_log = /mydata/data/relay-log read_only = 1 sync_master_info = 1 sync_relay_log = 1 sync_relay_log_info = 1
4.在master上创建复制用户：
service mysqld start /usr/local/mysql/bin/mysql -------------------------------------------> GRANT REPLICATION SLAVE,REPLICATION CLIENT ON *.* TO ‘slave‘@‘192.168.19.%‘ IDENTIFIED BY ‘123456‘; FLUSH PRIVILEGES;
5.在master上查看二进制日志位置：
SHOW MASTER LOGS;
6.两台slave上操作：
CHANGE MASTER TO MASTER_HOST=‘master‘,MASTER_USER=‘slave‘,MASTER_PASSWORD=‘123456‘,MASTER_LOG_FILE=‘master-bin.000001‘,MASTER_LOG_POS=637; START SLAVE; SHOW SLAVE STATUS\G
三、安装mysql-proxy
1.此实验中19.79为mysql-proxy服务器，所以软件安装在此主机上：
tar xf mysql-proxy-0.8.5-linux-el6-x86-64bit.tar.gz -C /usr/local/ cd /usr/local/ ln -sv mysql-proxy-0.8.5-linux-el6-x86-64bit mysql-proxy useradd -r mysql-proxy
2.提供服务脚本：
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<---------------------------------------------------------chmod +x /etc/init.d/mysql-proxychkconfig --add mysql-proxy3.为服务脚本提供配置文件：
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="" PROXY_USER="mysql-proxy" PROXY_OPTIONS="--daemon --log-level=info --log-use-syslog --plugins=proxy --plugins=admin --proxy-backend-addresses=192.168.19.66:3306 --proxy-read-only-backend-addresses=192.168.19.74:3306 --proxy-read-only-backend-addresses=192.168.19.76:3306 --proxy-lua-script=/usr/local/mysql-proxy/share/doc/mysql-proxy/rw-splitting.lua"//--daemon：以守护进程模式启动mysql-proxy//--proxy-backend-addresses：后端可读写的mysql服务器的地址和端口//--proxy-read-only-backend-addresses：后端只读mysql服务器的地址和端口//--proxy-lua-script：完成mysql代理功能的Lua脚本
4.提供admin.lua文件：
vim /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[i]
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
end5.为了使实验结果更明显，编辑rw-splitting.lua文件中的其中2个数值：
vim /usr/local/mysql-proxy/share/doc/mysql-proxy/rw-splitting.lua
--------------------------------------------------------------------------->
if not proxy.global.config.rwsplit then
proxy.global.config.rwsplit = {
min_idle_connections = 1, //默认为4
max_idle_connections = 1, //默认为8
is_debug = false
}
end //mysql-proxy会检测客户端连接，当连接没有超过min_idle_connections预设值时, 不会进行读写分离, 即查询操作会发生到Master上。5.启动mysql-proxy：
service mysql-proxy start ss -tnlp //查看端口
6.连接测试：
yum -y install mysql //如果没有mysql客户端的话执行此步 mysql -uadmin -padmin -h192.168.19.79 --port=4041 ------------------------------------------------------------> SELECT * FROM backends; +-------------+--------------------+---------+------+------+-------------------+ | backend_ndx | address | state | type | uuid | connected_clients | +-------------+--------------------+---------+------+------+-------------------+ | 1 | 192.168.19.66:3306 | unknown | rw | NULL | 0 | | 2 | 192.168.19.74:3306 | unknown | ro | NULL | 0 | | 3 | 192.168.19.76:3306 | unknown | ro | NULL | 0 | +-------------+--------------------+---------+------+------+-------------------+
四、读写分离测试：
1.在master上创建测试用户：
GRANT ALL ON *.* TO ‘jason‘@‘192.168.19.%‘ IDENTIFIED BY ‘123456‘; FLUSH PRIVILEGES;
2.分别在三台mariadb服务器上抓包：
master：
tcpdump -i eth0 -nn -XX ip dst 192.168.19.66 and tcp dst port 3306 //目标是19.66并且端口是3306
slave1：
tcpdump -i eth0 -nn -XX ip dst 192.168.19.74 and tcp dst port 3306
slave2：
tcpdump -i eth0 -nn -XX ip dst 192.168.19.76 and tcp dst port 3306
3.mysql-proxy上进行数据库操作：
mysql -ujason -p123456 -h192.168.19.79 -------------------------------------------------> CREATE DATABASE hello;USE mysql;SELECT * FROM user; //可以用额外的主机多执行几次
在master上的抓包信息：
在slave上的抓包信息：
4.查看状态，在proxy上操作，可以看到状态全部为up：
mysql -uadmin -padmin -h192.168.19.79 --port=4041 -------------------------------------------------------------> SELECT * FROM backends; +-------------+--------------------+-------+------+------+-------------------+ | backend_ndx | address | state | type | uuid | connected_clients | +-------------+--------------------+-------+------+------+-------------------+ | 1 | 192.168.19.66:3306 | up | rw | NULL | 0 | | 2 | 192.168.19.74:3306 | up | ro | NULL | 0 | | 3 | 192.168.19.76:3306 | up | ro | NULL | 0 | +-------------+--------------------+-------+------+------+-------------------+
五、拓展实验
1.在proxy上安装httpd和php：
yum install httpd php php-mysql service httpd start
2.让httpd可以支持index.php首页，然后放入wordpress页面文件，创建wordpress数据库并安装：
3.安装完后修改wordpress的配置文件，将master地址改为proxy的：
vim /var/www/html/wp-config.php
4.访问测试并抓包：
master：
slave：
转载链接：https://www.cnblogs.com/tae44/p/4701226.html