mysql-proxy篇二
MySQL-proxy篇二之读写分离。
实现MySQL的读写分离，在主从的架构中，既可以实现从服务器对主服务器的数据备份又可以分摊负载，降低服务器的压力。下面简单的介绍下应用。
master-server 192.168.5.1（既可以读又可以写），slave-server192.168.5.2（只读的MySQL-server），192.168.5.3 MySQL-proxy所在服务器。
1、 在官网可以下载MySQL-proxy。
现在好之后 直接解压。
tar xf mysql-proxy****.tar.gz –C /usr/local
ln –sv mysql-proxy*** mysql-proxy
chown root.mysql-proxy /usr/local/mysql-proxy/*
这运行MySQL-proxy的过程中。我们需要用到相应的用户，所以在这里需要提前创建好。
useradd –r mysql-proxy
解压完之后就可以直接应用，将mysql-proxy添加到相应的目录中去。
vi /etc/profile.d/mysql-proxy.sh
exportPATH=$PATH:/usr/local/mysql-proxy/bin
MySQL-proxy是一个可以解压就直接用的一个工具，现在我们就可以跟上相应的参数，然后进行应用了。
mysql-proxy
--daemon
--log-level=debug
--log-file=/var/log/mysql-proxy.log
--plugins=proxy
--proxy-backend-addresses=192.168.5.1
--proxy-read-only-backend-addresses=192.168.5.2
--proxy-lua-script=/usr/loca/mysql-proxy/share/doc/mysql-proxy/rw-spliting.lua
--plugins=admin
--admin-username=admin
--admin-password=admin
--admin-lua-script=/usr/loca/mysql-proxy/share/doc/mysql-proxy/admin.lua
mysql-proxy并没有给我们提供admin的lua脚本但是给我们提供了读写分离的脚本。也就是说MySQL的读写分离并不是由mysql-proxy实现的。他是由lua脚本实现的。
下面自己建立admin的lua脚本
vi/usr/local/mysql-proxy/share/doc/mysql-proxy/admin.lua
function set_error(errmsg)
proxy.response= {
type= proxy.MYSQLD_PACKET_ERR,
errmsg= errmsg or "error"
}
end
function read_query(packet)
ifpacket:byte() ~= proxy.COM_QUERY then
set_error("[admin]we only handle text-based queries (COM_QUERY)")
returnproxy.PROXY_SEND_RESULT
end
localquery = packet:sub(2)
localrows = { }
localfields = { }
ifquery: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 },
}
fori = 1, #proxy.global.backends do
localstates = {
"unknown",
"up",
"down"
}
localtypes = {
"unknown",
"rw",
"ro"
}
localb = 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 downstarting at 0
b.uuid, -- the MySQL Server's UUID if itis managed
b.connected_clients -- currently connected clients
}
end
elseifquery: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 theirstate" }
else
set_error("use'SELECT * FROM help' to see the supported commands")
returnproxy.PROXY_SEND_RESULT
end
proxy.response= {
type= proxy.MYSQLD_PACKET_OK,
resultset= {
fields= fields,
rows= rows
}
}
returnproxy.PROXY_SEND_RESULT
end
如果启动成功的话，会有两个端口启动分别是4040端口和4041端口，其中4040端口mysql-proxy的工作端口，4041端口是admin的端口。端口启动之后，在mysql的master端建立一个可以供mysql-proxy登录的账号。
mysql>grant all on *.* to root@’192.168.%.%’ identified by‘redhat’;
mysql>flush privileges;
登录尝试：
mysql –uroot –h192.168.5.3 –port=4040 –p //连接上之后就可以进行mysql的读写操作了。
mysql –uadmin –h192.168.5.3 –port=4041 –p//连接之后是mysql-proxy的管理端口
mysql>select * from backends;
显示的是读写服务器是否已经启动并且被激活参加了工作。如果被激活那么显示的是up的状态。
下面介绍下用脚本启动mysql-proxy
vi /etc/init.d/mysql-proxy
#!/bin/bash
#
# mysql-proxy This script starts and stopsthe mysql-proxy daemon
#
# chkconfig: - 78 30
# processname: mysql-proxy
# description: mysql-proxy is a proxydaemon 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="$ADMIN_PASSWD"
RETVAL=$?
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
vi /etc/sysconfig/mysql-proxy 编辑脚本的配置文件，为脚本传递参数。
ADMIN_USER="admin"
ADMIN_PASSWD="admin"
ADMIN_LUA_SCRIPT="/usr/local/mysql-proxy/share/doc/mysql-proxy/admin.lua"
PROXY_PID=/var/run/mysql-proxy.pid
PROXY_USER="mysql-proxy"
PROXY_OPTIONS=” –daemon –log-level=debug–log-file=/var/log/mysql-proxy.log –plugins=proxy–proxy-backend-addresses=192.168.5.1:3306–proxy-read-only-backend-addresses=192.168.5.2:3306 –plugins=admin–admin-username=admin –admin-password=admin–proxy-lua-script=/usr/local/mysql-proxy/share/doc/mysql-proxy/rw-spliting.lua”
chmod +x /etc/init.d/mysql-proxy
chmod 660 /etc/sysconfig/mysql-proxy
service mysql-proxy start //启动服务
这样我们就可以使用mysql-proxy了。