mysql-proxy 的 administration 接口可以通过任何 MySQL 客户端按照标准协议进行访问。你可以通过 administration 接口获取 proxy 服务器的整体信息 - 向 proxy 建立的标准连接是处于隔离状态的,其模拟了直接连接到后端 MySQL 服务器的情形。
在 mysql-proxy 0.8.0 或者更早的版本中,一组最基本的接口已被添加到 proxy 中。在后续版本中,这种方式已被替换,你必须要使用的 administration 脚本以连接到 administration 接口。
为了使用 administration 接口,需要通过 --admin-username 和 --admin-password 选项指定连接 admin 服务器所需的用户名和密码。同样必须通过 admin-lua-script 脚本选项指定提供访问 administration 服务所需接口的 Lua 脚本。
例如,你可以使用下面的脚本创建一个访问 mysql-proxy 系统内部组件基本接口,由 Diego Medina 提供:
--[[ Copyright 2008, 2010, 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 Street, Fifth Floor, Boston, MA 02110-1301 USA --]] -- admin.lua --[[ See http://www.chriscalender.com/?p=41 (Thanks to Chris Calender) See http://datacharmer.blogspot.com/2009/01/mysql-proxy-is-back.html (Thanks Giuseppe Maxia) --]] 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 = { } -- try to match the string up to the first non-alphanum local f_s, f_e, command = string.find(packet, "^%s*(%w+)", 2) local option if f_e then -- if that match, take the next sub-string as option f_s, f_e, option = string.find(packet, "^%s+(%w+)", f_e + 1) end -- we got our commands, execute it if command == "show" and option == "querycounter" then --- -- proxy.PROXY_SEND_RESULT requires -- -- proxy.response.type to be either -- * proxy.MYSQLD_PACKET_OK or -- * proxy.MYSQLD_PACKET_ERR -- -- for proxy.MYSQLD_PACKET_OK you need a resultset -- * fields -- * rows -- -- for proxy.MYSQLD_PACKET_ERR -- * errmsg proxy.response.type = proxy.MYSQLD_PACKET_OK proxy.response.resultset = { fields = { { type = proxy.MYSQL_TYPE_LONG, name = "query_counter", }, }, rows = { { proxy.global.query_counter } } } -- we have our result, send it back return proxy.PROXY_SEND_RESULT elseif command == "show" and option == "myerror" then proxy.response.type = proxy.MYSQLD_PACKET_ERR proxy.response.errmsg = "my first error" return proxy.PROXY_SEND_RESULT elseif string.sub(packet, 2):lower() == 'select help' then return show_process_help() elseif string.sub(packet, 2):lower() == 'show proxy processlist' then return show_process_table() elseif query == "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 }, } for i = 1, #proxy.global.backends do local b = proxy.global.backends[i] rows[#rows + 1] = { i, b.dst.name, b.state, b.type } end else set_error() return proxy.PROXY_SEND_RESULT end proxy.response = { type = proxy.MYSQLD_PACKET_OK, resultset = { fields = fields, rows = rows } } return proxy.PROXY_SEND_RESULT end function make_dataset (header, dataset) proxy.response.type = proxy.MYSQLD_PACKET_OK proxy.response.resultset = { fields = {}, rows = {} } for i,v in pairs (header) do table.insert(proxy.response.resultset.fields, {type = proxy.MYSQL_TYPE_STRING, name = v}) end for i,v in pairs (dataset) do table.insert(proxy.response.resultset.rows, v ) end return proxy.PROXY_SEND_RESULT end function show_process_table() local dataset = {} local header = { 'Id', 'IP Address', 'Time' } local rows = {} for t_i, t_v in pairs (proxy.global.process) do for s_i, s_v in pairs ( t_v ) do table.insert(rows, { t_i, s_v.ip, os.date('%c',s_v.ts) }) end end return make_dataset(header,rows) end function show_process_help() local dataset = {} local header = { 'command', 'description' } local rows = { {'SELECT HELP', 'This command.'}, {'SHOW PROXY PROCESSLIST', 'Show all connections and their true IP Address.'}, } return make_dataset(header,rows) end function dump_process_table() proxy.global.initialize_process_table() print('current contents of process table') for t_i, t_v in pairs (proxy.global.process) do print ('session id: ', t_i) for s_i, s_v in pairs ( t_v ) do print ( '\t', s_i, s_v.ip, s_v.ts ) end end print ('---END PROCESS TABLE---') end --[[ Help we use a simple string-match to split commands are word-boundaries mysql> show querycounter is split into command = "show" option = "querycounter" spaces are ignored, the case has to be as is. mysql> show myerror returns a error-packet --]]
上述脚本需要配合下面的 proxy 脚本一起使用,名字为 reporter.lua :
--[[ Copyright 2008, 2010, 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 Street, Fifth Floor, Boston, MA 02110-1301 USA --]] -- reporter.lua --[[ See http://www.chriscalender.com/?p=41 (Thanks to Chris Calender) See http://datacharmer.blogspot.com/2009/01/mysql-proxy-is-back.html (Thanks Giuseppe Maxia) --]] proxy.global.query_counter = proxy.global.query_counter or 0 function proxy.global.initialize_process_table() if proxy.global.process == nil then proxy.global.process = {} end if proxy.global.process[proxy.connection.server.thread_id] == nil then proxy.global.process[proxy.connection.server.thread_id] = {} end end function read_auth_result( auth ) local state = auth.packet:byte() if state == proxy.MYSQLD_PACKET_OK then proxy.global.initialize_process_table() table.insert( proxy.global.process[proxy.connection.server.thread_id], { ip = proxy.connection.client.src.name, ts = os.time() } ) end end function disconnect_client() local connection_id = proxy.connection.server.thread_id if connection_id then -- client has disconnected, set this to nil proxy.global.process[connection_id] = nil end end --- -- read_query() can return a resultset -- -- You can use read_query() to return a result-set. -- -- @param packet the mysql-packet sent by the client -- -- @return -- * nothing to pass on the packet as is, -- * proxy.PROXY_SEND_QUERY to send the queries from the proxy.queries queue -- * proxy.PROXY_SEND_RESULT to send your own result-set -- function read_query( packet ) -- a new query came in in this connection -- using proxy.global.* to make it available to the admin plugin proxy.global.query_counter = proxy.global.query_counter + 1 end
为了使用上述脚本,首先需要将第一个脚本保存为文件(在下面的例子中文件名为 admin.lua ),第二个命名为 reporter.lua ,然后通过命令指定 mysql-proxy 执行的 admin 脚本和后端 MySQL 服务器:
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shell> mysql-proxy --admin-lua-script=admin.lua --admin-password=password \ »
--admin-username=root --proxy-backend-addresses=127.0.0.1:3306 -proxy-lua-script=reporter.lua
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在另外一个窗口中,通过 proxy 连接 MySQL 服务器:
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shell> mysql --user=root --password=password --port=4040
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection
id
is 1798669
Server version: 5.0.70-log Gentoo Linux mysql-5.0.70-r1
Type
'help;'
or
'\h'
for
help. Type
'\c'
to
clear
the buffer.
mysql>
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在第三个窗口中,使用指定的用户名和密码连接 mysql-proxy 的 admin 服务:
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shell> mysql --user=root --password=password --port=4041 --host=localhost
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection
id
is 1
Server version: 5.0.99-agent-admin
Type
'help;'
or
'\h'
for
help. Type
'\c'
to
clear
the buffer.
mysql>
|
为了监视 proxy 的状态信息,可以请求当前活动进行的列表信息:
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mysql> show proxy processlist;
+
---------+---------------------+--------------------------+
| Id | IP Address |
Time
|
+
---------+---------------------+--------------------------+
| 1798669 | 192.168.0.112:52592 | Wed Jan 20 16:58:00 2010 |
+
---------+---------------------+--------------------------+
1 row
in
set
(0.00 sec)
mysql>
|