MySQL Proxy簡介
MySQL Proxy(MySQL代理)是一個通過MySQL網絡協議，提供MySQL服務器與客戶端之間連接的應用工具，在基本配置條件下，MySQL代理僅是傳遞客戶端發出的查詢請求到MySQL服務器端，而後返回MySQL服務器的響應到客戶端。
由於MySQL代理使用的MySQL網絡協議，因此所有MySQL兼容的客戶端(包括mysql命令行、調用mysql命令行的類庫、以及支持MySQL網絡協議的應用)均可無需修改連接代理。
通過配置，MySQL代理同樣能夠監測及修改客戶端與服務器端的通訊，這樣DBA可以控制客戶端提交的查詢，比如調整查詢的結果集，甚至可以跳過MySQL數據庫，直接返回數據給客戶端。
場景描述：
數據庫Master主服務器：192.168.90.128
數據庫Slave從服務器：192.168.90.129
數據庫Slave從服務器：192.168.90.130
MySQL-Proxy調度服務器：192.168.90.130
以下操作，均是在192.168.90.130 即MySQL-Proxy調度服務器 上進行的。
MySQL的安裝與配置
安裝過程參見安裝文檔
檢查系統所需軟件包
shell> rpm -q libevent lua glib2 pkgconfig libtool ncurses-devel readline-devel
libevent-1.4.13-1.el6.i686
lua-5.1.4-4.1.el6.i686
glib2-2.22.5-6.el6.i686
pkgconfig-0.23-9.1.el6.i686
libtool-2.2.6-15.5.el6.i686
ncurses-devel-5.7-3.20090208.el6.i686
readline-devel-6.0-3.el6.i686安裝MySQL-Proxy
源碼安裝
shell> tar zxvf mysql-proxy-0.8.5.tar.gz -C /db/tool/
shell> cd /db/tool/mysql-proxy-0.8.5
shell> ./configure
checking pkg-config is at least version 0.9.0... yes
checking for LUA... no
... checked for Lua via pkg-config: No package 'lua' found. retrying with lua5.1
checking for LUA... no
configure: error: checked for Lua via pkg-config: No package 'lua5.1' found. Make sure lua and its devel-package,
which includes the lua5.1.pc (debian and friends) or lua.pc (all others) file, is installed
shell> export LUA_CFLAGS="-I/usr/local/include"
shell> export LUA_LIBS="-L/usr/local/lib -llua -ldl"
shell> ./configure
checking for LUA... yes
checking for GLIB... yes
checking for GMODULE... yes
checking for GTHREAD... yes
checking for inet_ntoa... yes
checking for inet_ntop... yes
checking for strerror... yes
checking for getcwd... yes
checking for chdir... yes
checking for writev... yes
checking for gmtime_r... yes
checking for sigaction... yes
checking for getaddrinfo... yes
checking size of rlim_t... 0
checking for event_init in -levent... no
configure: error: libevent is required
shell> tar xvfz libevent-1.4.14b-stable.tar.gz
shell> cd libevent-1.4.14b-stable
shell> ./configure --prefix=/usr/local/libevent-1.4
shell> make && make install
shell> export LDFLAGS="-L/usr/local/libevent-1.4/lib -lm"
shell> ./configure --prefix=/usr/local/mysql-proxy
shell> make && make install
編譯好的二進制安裝(推薦)
shell> tar xzvf mysql-proxy-0.8.1-linux-rhel5-x86-32bit.tar.gz -C /usr/local/
shell> mv /usr/local/mysql-proxy-0.8.1-linux-rhel5-x86-32bit /usr/local/mysql-proxy
shell> export PATH=$PATH:/usr/local/mysql-proxy/bin
驗證安裝後，驗證安裝結果
shell> mysql-proxy -V
mysql-proxy 0.8.5
chassis: 0.8.5
glib2: 2.16.6
libevent: 2.0.21-stable
LUA: Lua 5.1.4
package.path: /usr/local/mysql-proxy/lib/mysql-proxy/lua/?.lua;
package.cpath: /usr/local/mysql-proxy/lib/mysql-proxy/lua/?.so;
-- modules
proxy: 0.8.5MySQL Proxy配置選項
shell> mysql-proxy --help-all
Usage:
mysql-proxy [OPTION...] - MySQL Proxy
Help Options:
-?, --help Show help options
--help-all Show all help options
--help-proxy Show options for the proxy-module
proxy-module
-P, --proxy-address=<host:port> listening address:port of the proxy-server (default: :4040)
-r, --proxy-read-only-backend-addresses=<host:port> address:port of the remote slave-server (default: not set)
-b, --proxy-backend-addresses=<host:port> address:port of the remote backend-servers
(default: 127.0.0.1:3306)
--proxy-skip-profiling disables profiling of queries (default: enabled)
--proxy-fix-bug-25371 fix bug #25371 (mysqld > 5.1.12) for older libmysql versions
-s, --proxy-lua-script=<file> filename of the lua script (default: not set)
--no-proxy don't start the proxy-module (default: enabled)
--proxy-pool-no-change-user don't use CHANGE_USER to reset the connection coming from
the pool (default: enabled)
--proxy-connect-timeout connect timeout in seconds (default: 2.0 seconds)
--proxy-read-timeout read timeout in seconds (default: 8 hours)
--proxy-write-timeout write timeout in seconds (default: 8 hours)
Application Options:
-V, --version Show version
--defaults-file=<file> configuration file
--verbose-shutdown Always log the exit code when shutting down
--daemon Start in daemon-mode
--user=<user> Run mysql-proxy as user
--basedir=<absolute path> Base directory to prepend to relative paths in the config
--pid-file=<file> PID file in case we are started as daemon
--plugin-dir=<path> path to the plugins
--plugins=<name> plugins to load
--log-level=(error|warning|info|message|debug) log all messages of level ... or higher
--log-file=<file> log all messages in a file
--log-use-syslog log all messages to syslog
--log-backtrace-on-crash try to invoke debugger on crash
--keepalive try to restart the proxy if it crashed
--max-open-files maximum number of open files (ulimit -n)
--event-threads number of event-handling threads (default: 1)
--lua-path=<...> set the LUA_PATH
--lua-cpath=<...> set the LUA_CPATH配置MySQL Proxy
修改讀寫分離腳本rw-splitting.lua
修改默認連接，進行快速測試，不修改的話要達到連接數爲4時才啓用讀寫分離
shell> vim /usr/local/mysql-proxy/share/doc/mysql-proxy/rw-splitting.lua
===========================================
-- connection pool
if not proxy.global.config.rwsplit then
proxy.global.config.rwsplit = {
min_idle_connections = 1, #默認爲4
max_idle_connections = 1, #默認爲8
is_debug = false
}
end
===========================================
shell> vim /etc/mysql-proxy.cnf
===========================================
[mysql-proxy]
#管理員用戶
admin-username = root
#管理員密碼
admin-password = mypass
#管理模塊腳本
admin-lua-script = /usr/local/mysql-proxy/lib/mysql-proxy/lua/admin.lua
#讀寫分離腳本
proxy-lua-script = /usr/local/mysql-proxy/share/doc/mysql-proxy/rw-splitting.lua
#守護進程模式運行
daemon = true
#mysql proxy的監聽端口
proxy-address=0.0.0.0:3333
#指定MySQL主庫
proxy-backend-addresses = 192.168.90.128:3306
#指定MySQL備庫
proxy-read-only-backend-addresses = 192.168.90.129:3306
proxy-read-only-backend-addresses = 192.168.90.130:3306
pid-file=/usr/local/mysql-proxy/mysql-proxy.pid
user=root
log-level=info
log-file=/tmp/mysql-proxy.log
===========================================
shell> chomd 660 /etc/mysql-proxy.cnf
shell> mysql-proxy --defaults-file=/etc/mysql-proxy.cnf
shell> netstat -lnt
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 0.0.0.0:111 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN
tcp 0 0 127.0.0.1:631 0.0.0.0:* LISTEN
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:39481 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:3333 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:5672 0.0.0.0:* LISTEN
tcp 0 0 :::111 :::* LISTEN
tcp 0 0 :::22 :::* LISTEN
tcp 0 0 ::1:631 :::* LISTEN
tcp 0 0 ::1:25 :::* LISTEN
tcp 0 0 :::60455 :::* LISTEN
tcp 0 0 :::3306 :::* LISTEN測試讀寫分離效果
創建用於讀寫分離的數據庫連接用戶，登陸主庫服務器192.168.90.128
shell> mysql -uroot -p
mysql> GRANT ALL ON *.* TO 'proxy_test'@'%' IDENTIFIED BY 'proxy';
[192.168.90.130]
mysql> stop slave;
Query OK, 0 rows affected (0.03 sec)
連接MySQL-Proxy
shell> mysql -u proxy_test -h 192.168.90.130 -P3333 -pproxy
mysql> insert into t values (2),(3),(4);
Query OK, 3 rows affected (0.01 sec)
Records: 3 Duplicates: 0 Warnings: 0
查看主庫192.168.90.128
mysql> select * from uuu.t;
+------+
| id |
+------+
| 1 |
| 2 |
| 3 |
| 4 |
+------+
4 rows in set (0.00 sec)
查看備庫192.168.90.129
mysql> select * from uuu.t;
+------+
| id |
+------+
| 1 |
| 2 |
| 3 |
| 4 |
+------+
4 rows in set (0.00 sec)
查看備庫192.168.90.130
mysql> select * from uuu.t;
+------+
| id |
+------+
| 1 |
+------+
1 row in set (0.00 sec)
mysql> start slave;
Query OK, 0 rows affected (0.02 sec)
mysql> select * from uuu.t;
+------+
| id |
+------+
| 1 |
| 2 |
| 3 |
| 4 |
+------+
4 rows in set (0.00 sec)
代理端口
mysql> select * from uuu.t;
+------+
| id |
+------+
| 1 |
| 2 |
| 3 |
| 4 |
+------+
4 rows in set (0.00 sec)
由此驗證，我們已經實現了MySQL讀寫分離，目前所有的寫操作都全部在Master主服務器上，用來避免數據的不同步；
另外，所有的讀操作都分攤到Slave從服務器上，用來分擔數據庫壓力。
整理自網絡
Svoid
2015-01-13