mysql读写分离[高可用]
顾名思义, 在mysql负载均衡中有多种方式, 本人愚钝,只了解驱动中间件和mysql_proxy两种方式, 对于驱动,利用的是ReplicationDriver,具体请看远哥的这篇文章: MySQL读写分离又一好办法 使用 com.mysql.jdbc.ReplicationDriver
本次我要实现利用的方式是: mysql_proxy
下面进入主题
mysql_proxy:192.168.99.55
master:192.168.99.61
slave:192.168.99.62
1.安装mysql_proxy
1 2 3 4 5 | tar -zxvf mysql-proxy-0.8.4-linux-rhel5-x86-64bit. tar .gz -C /usr/local cd /usr/local mv mysql-proxy-0.8.4-linux-rhel5-x86-64bit mysql-proxy |
下面是需要的依赖
1 2 | gcc * gcc -c++* autoconf* automake* zlib* libxml* ncurses-devel* libmcrypt* libtool* flex* pkgconfig* libevent* glib* readline-devel |
2.添加代理用户
1 | useradd -r mysql-proxy |
3.sysv服务脚本mysql_proxy
这个脚本放置的位置是:/etc/init.d
记得授权,chmod +x /etc/init.d/mysql_proxy
这个脚本是用来做快捷启动的。
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 | #!/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 |
4.为服务脚本提供配置文件mysql_proxy
这个脚本放在的位置是:/etc/sysconfig(我是根据上面服务脚本的位置放的, 喜欢放在别处的地方可以自行修改)。
1 2 3 4 5 6 7 8 | # 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=192.168.99.61:3306 <br>--proxy-read-only-backend-addresses=192.168.99.62:3306 --proxy-lua-script=/usr/local/mysql-proxy/share/doc/mysql-proxy/rw-splitting.lua" |
5.创建admin.lua
这个脚本放置的位置是:/usr/local/mysql-proxy/share/doc/mysql-proxy
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 | --[[ $%BEGINLICENSE%$ 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 end |
6.修改rw-splitting.lua
修改的是min_idle_connections和max_idle_connections的值,都等于1
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | local commands = require( "proxy.commands" ) local tokenizer = require( "proxy.tokenizer" ) local lb = require( "proxy.balance" ) local auto_config = require( "proxy.auto-config" ) --- config -- -- connection pool if not proxy.global.config.rwsplit then proxy.global.config.rwsplit = { min_idle_connections = 1, max_idle_connections = 1, is_debug = false } end |
7.测试mysql_proxy
7.1启动mysql_proxy
1 | service mysql_proxy start |
7.2端口进程状态
进程
1 2 3 4 5 | ps aux | grep mysql-proxy root 14230 0.0 0.0 103244 836 pts /0 S+ 11:25 0:00 grep mysql-proxy 496 28239 0.0 0.0 45772 2104 ? S Dec04 0:03 /usr/local/mysql-proxy/libexec/mysql-proxy --daemon --log-level=info --log-use-syslog --plugins=proxy --plugins=admin --proxy-backend-addresses=192.168.75.61:3306 --proxy- read -only-backend-addresses=192.168.75.62:3306 --proxy-lua-script= /usr/local/mysql-proxy/share/doc/mysql-proxy/rw-splitting .lua --pid- file = /var/run/mysql-proxy .pid --proxy-address= --user=mysql-proxy --admin-username=admin --admin-lua-script= /usr/local/mysql-proxy/share/doc/mysql-proxy/admin .lua --admin-password=admin |
端口
1 2 3 4 5 | netstat -tlnp | grep mysql-proxy tcp 0 0 0.0.0.0:4041 0.0.0.0:* LISTEN 28239 /mysql-proxy tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 28239 /mysql-proxy |
看到上面, 端口有4041与3306, 这两个端口都是关键所在,下面将进行解题。
7.3登录mysql_proxy
随便找一台有mysql客户端的机器登录到mysql_proxy192.168.99.55(也可以在99.55上面安装mysql客户端, 我是在别的机器连得), 这个登录使用的账号密码还记得把?它就是脚本中指定的账号密码,admin:admin
1 | mysql -u admin -p -h 192.168.99.55 --port=4041 |
必须指定端口, 不然跑的是3306
7.4查询状态
7.4.1 select * from help
1 2 3 4 5 6 7 | +------------------------+------------------------------------+ | command | description | +------------------------+------------------------------------+ | SELECT * FROM help | shows this help | | SELECT * FROM backends | lists the backends and their state | +------------------------+------------------------------------+ 2 rows in set (0.00 sec) |
7.4.2 SELECT * FROM backends
1 2 3 4 5 6 7 | +-------------+--------------------+-------+------+------+-------------------+ | backend_ndx | address | state | type | uuid | connected_clients | +-------------+--------------------+-------+------+------+-------------------+ | 1 | 192.168.99.61:3306 | down | rw | NULL | 0 | | 2 | 192.168.99.62:3306 | down | ro | NULL | 0 | +-------------+--------------------+-------+------+------+-------------------+ 2 rows in set (0.00 sec) |
看到上面的信息, master99.61的type是rw(支持读写),slave99.62的type是ro(只读)
7.5抓包分析
在master上:
1 | tcpdump -i eth0 -nn -XX ip dst 192.168.99.61 and tcp dst port 3306 |
在slave上:
1 | tcpdump -i eth0 -nn -XX ip dst 192.168.99.62 and tcp dst port 3306 |
7.5.1主从分析
为了更明显操作结果, 停止主从
登录mysql_proxy
1 | mysql -u admin -p -h 192.168.75.55 --port=3306 |
这次登录的是3306, 上面登录的是4041,请大家不要混淆。
至于3306与4041有什么不一样, 下面我解析一下, 4041就是查询读写分离的状态的, 3306无疑就是提供给外部的接口。
现在往test表插入一条数据
1 | insert into test .testtest values(80, '80' ); |
下面查询, 是查询不到的, 因为主从已经断开, 查的是往62跑, 写是写进61了, 只要把主从配置回来一切正常。
上面的抓包就是没操作一下都会有记录, 这次很明显看出来读写分析所跑的机器。
进行写时, master抓到的包是:
1 2 3 4 5 6 7 8 9 10 11 12 13 | 14:25:28.835455 IP 192.168.99.55.45648 > 192.168.99.61.3306: Flags [P.], seq 2082548409:2082548453, ack 3795613073, win 173, options [nop,nop,TS val 2915927263 ecr 2948974813], length 44 0x0000: 0050 5689 cba6 0050 5689 9616 0800 4508 .PV....PV.....E. 0x0010: 0060 994f 4000 4006 897b c0a8 4b37 c0a8 .`.O@.@..{..K7.. 0x0020: 4b3d b250 0cea 7c21 2ab9 e23c 7591 8018 K=.P..|!*..<u... 0x0030: 00ad eed3 0000 0101 080a adcd 84df afc5 ................ 0x0040: c8dd 2800 0000 0369 6e73 6572 7420 696e ..(....insert. in 0x0050: 746f 2074 6573 742e 7465 7374 7465 7374 to.test.testtest 0x0060: 2076 616c 7565 7328 322c 2732 2729 .values(2, '2' ) 14:25:28.836543 IP 192.168.99.55.45648 > 192.168.99.61.3306: Flags [.], ack 12, win 173, options [nop,nop,TS val 2915927264 ecr 2949040785], length 0 0x0000: 0050 5689 cba6 0050 5689 9616 0800 4508 .PV....PV.....E. 0x0010: 0034 9950 4000 4006 89a6 c0a8 4b37 c0a8 .4.P@.@.....K7.. 0x0020: 4b3d b250 0cea 7c21 2ae5 e23c 759c 8010 K=.P..|!*..<u... 0x0030: 00ad f329 0000 0101 080a adcd 84e0 afc6 ...)............ |
slave此时的状态是:
1 2 | tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes |
进行读时, slave的状态是:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 | 15:00:36.252068 IP 192.168.99.55.40191 > 192.168.99.62.3306: Flags [P.], seq 853416170:853416202, ack 2118301929, win 184, options [nop,nop,TS val 2915944710 ecr 2911691799], length 32 0x0000: 0050 5689 a328 0050 5689 9616 0800 4508 .PV..(.PV.....E. 0x0010: 0054 7caa 4000 4006 a62b c0a8 4b37 c0a8 .T|.@.@..+..K7.. 0x0020: 4b3e 9cff 0cea 32de 18ea 7e42 b8e9 8018 K>....2...~B.... 0x0030: 00b8 0093 0000 0101 080a adcd c906 ad8c ................ 0x0040: e417 1c00 0000 0373 656c 6563 7420 2a20 ....... select .*. 0x0050: 6672 6f6d 2074 6573 742e 7465 7374 7465 from .test.testte 0x0060: 7374 st 15:00:36.253339 IP 192.168.99.55.40191 > 192.168.99.62.3306: Flags [.], ack 144, win 223, options [nop,nop,TS val 2915944712 ecr 2912255989], length 0 0x0000: 0050 5689 a328 0050 5689 9616 0800 4508 .PV..(.PV.....E. 0x0010: 0034 7cab 4000 4006 a64a c0a8 4b37 c0a8 .4|.@.@..J..K7.. 0x0020: 4b3e 9cff 0cea 32de 190a 7e42 b978 8010 K>....2...~B.x.. 0x0030: 00df 8c29 0000 0101 080a adcd c908 ad95 ...)............ 0x0040: 7ff5 .. |
最终拓扑