最近写的一个mysql读写分离的，python 小工具：angel mysql proxy

mysql 读写分离在面对一定的数据库压力下，的确有一定的帮助，读写分离方面的程序似乎也很多，mysql 官方也有个读写分离产品叫

 

MySQL Proxy 。  按照我理解，似乎实现基本的读写分离也不是很难。所以我按照自己的想法写了一个。目前在并发600的情况下是成功的。并发超过600后就有收割僵尸进程不完成的情况，导致进程假死状态。这个目前有个解决想法，就是把收割程序独立出来用一个进程来专门收割，这样可以防止，收割程序在并发大阻塞下响应不及时问题。~_~ 只是个想法。。

 

 

下载地址：我放phchina.com上了。 CSDN不知道咋传的郁闷

 

http://bbs.phpchina.com/viewthread.php?tid=173892

 

目前流程：

 

php客户端  -->   angel.py -- ---读写分离：读均衡 --->  mysql

 

 

angel mysql proxy 在并发模型上选择了 forking 。在均衡读上的算法目前只是随机，因为开发当时遇到个问题就是，如何把子进程使用

 

mysql 的状态数给保存下来传给主进程，然后主进程按照目前的各mysql 连接数均衡分配客户端读。 那会第一反应就是使用 file 来进行 进程间共享。但存在个锁问题。担心效率受损。 进而想到了 共享内存。不过找不到合适的py库。 今天才确定pipe 应该能解决这个问题 ~_~ 目前也只是个想法。。

 

在收割上，循环收割和信号收割。经过测试最后选择了信号收割，在并发下，似乎收割情况更好点

 

先看下配置文件，我直接使用了PY文件了。贪图方便

 

#!/usr/bin/python # -*- coding:utf-8 -*- #读mysql rd = {'host':'127.0.0.1', 'user':'root', 'passwd':'1', 'database':'beihai365'} #写mysql wt = {'host':'127.0.0.1', 'user':'root', 'passwd':'1', 'database':'beihai365'} read_mysql_server = (rd,wt) write_mysql_server = wt charset = 'gbk' error_log = '/var/log/angel.log'

 

定义日志：默认日志是 angel.log   里面主要记录了

查询mysql 的出错信息等。可以扩展

采集部分：

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'ELECT * FROM salary' at line 1
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'ELECT * FROM salary' at line 1

 

 

一看大概就明白了吧， 两台mysql 一台是读，一台是写，不过写的当然我们也可以读，那么等于是 read 两台  write 一台，当然按照配置文件可以放更多的read 服务器，写 mysql 目前我只允许一台，实现多台写也是比较简单的。

 

目前看这个配置，我只是是使用同一台mysql。。等改天有环境了再真的分离开吧。不过目前我在程序上加了调试，可以看得出，两台mysql轮流服务的效果。

 

目前查询的语句是这样的：select * from cdb_posts limit 20

 

 

 

目前这个表的数据情况是这样的：

 

beihai365# mysqlshow -u root -p beihai365 cdb_posts --count
Enter password:
Database: beihai365  Wildcard: cdb_posts
+-----------+----------+------------+
|  Tables   | Columns  | Total Rows |
+-----------+----------+------------+
| cdb_posts |       21 |   11922687 |
+-----------+----------+------------+
1 row in set.

 

 

测试我使用了 webbench

 

1.运行 angel.py ，这个是 读写分离的服务端，只有一个文件。

 

beihai365# python angel.py

2. 开始运行 客户端脚本，我用php简单的封装了一个使用 angel.py 的类。 有了这个，我们就可以把angel mysql proxy 融入 PHP开发的项目中了。

 

 

 

angel.py 返回给客户端的是： 串行化的 array  。 这样PHP操作就方便了

 

beihai365# webbench -c 300 http://192.168.18.2/angel_proxy.php

 

 

 

angel.py 服务端在并发下显示（我在程序中加入的调试信息）：

 

mysqld is 1  (使用了第二台mysql)
mysqld is 0 (使用了第一台mysql)
complete its work (子进程完成了查询任务)
reap child sucess 15258(收割了15258进程)
reap child sucess 15257...
complete its work..
complete its work...
reap child sucess 15261...
reap child sucess 15260..

 

webbench 显示：

 

Webbench - Simple Web Benchmark 1.5
Copyright (c) Radim Kolar 1997-2004, GPL Open Source Software.

Benchmarking: GET http://192.168.18.2/angel_proxy.php
300 clients, running 30 sec.

Speed=43020 pages/min, 2738034 bytes/sec.
Requests: 21510 susceed, 0 failed.

OK。没有比较就不知道这样的结果是否是满意的。那么我就去掉angel.py 这个服务，直接使用php来对mysql 进行读操作。然后看下效率如何

 

 

beihai365# webbench -c 300 http://192.168.18.2/test.php
Webbench - Simple Web Benchmark 1.5
Copyright (c) Radim Kolar 1997-2004, GPL Open Source Software.

Benchmarking: GET http://192.168.18.2/test.php
300 clients, running 30 sec.

Speed=47556 pages/min, 27228021 bytes/sec.
Requests: 23778 susceed, 0 failed.

相差不多。但别忘了。我这可是读写分离了，在真的读写分离情况下，angel.py 性能应该能提高很多。呵呵 这个以后搭建环境后测试，在公布结果。

 

 

 贴代码：

angel.py

 

#!/usr/local/bin/python # -*- coding:utf-8 -*- import socket,os,sys,time,MySQLdb,traceback,string,random,fcntl,signal from angel_conf import * #定义读写语句 read_sql_conf = ('select') write_sql_conf = ('delete','update','alter') mysql_read_switch = mysql_write_switch = 0 cluster = {} def pre_match_sql(data): return string.lower(data[:data.index(' ')].strip()) def seekreadmysql(): random.seed() randmysqld = random.choice([i for i in range(len(read_mysql_server))]) print 'mysqld is %s' % randmysqld return read_mysql_server[randmysqld] def seekwritemysql(): return write_mysql_server def strlen(strs): return len(str(strs)) def reap(signum,stackframe): '''reap subfork''' while True: try: result = os.waitpid(-1,os.WNOHANG) if not result[0]: break print 'reap child sucess %d' % result[0] except: break signal.signal(signal.SIGCHLD,reap) def serialize(rows): sqltostr = '';i = 0;j = 1 for row in rows: if j == 1: bracket = '' else: bracket = '}' sqltostr += '%si:%d;a:%d:{' % (bracket,j,len(row)) j += 1 for key in row: sqltostr += 's:%d:"%s";s:%d:"%s";' % (strlen(key),key,strlen(row[key]),row[key]) i += 1 heads = 'a:%d:{' % int(j-1) sqltostr = heads + sqltostr + '}}' return sqltostr class nettpl_content: def __init__(self,clientsk): self._clientsk = clientsk def myhandler(self,rcmysql): action = pre_match_sql(rcmysql) if not len(action): sys.exit(4) #allow read global mysql_read_switch; global mysql_write_switch; global cluster if action in read_sql_conf: try: if not mysql_read_switch: rl = seekreadmysql() cluster['readconn'] = MySQLdb.connect(host=rl['host'],user=rl['user'],passwd=rl['passwd'],db=rl['database']) mysql_read_switch = 1 except MySQLdb.Error: print 'mysql connect error' sys.exit(1) try: rdcursor = cluster['readconn'].cursor(MySQLdb.cursors.DictCursor) rdcursor.execute("SET NAMES %s" % charset) rdcursor.execute(rcmysql) rows = rdcursor.fetchall() except MySQLdb.Error,e: errormsg = str(e.args[1]) self._clientsk.sendall(errormsg) self.halt(rmsg) sys.exit(1) sqltostr = serialize(rows) self._clientsk.sendall(sqltostr) #self._clientsk.close() rdcursor.close() else: try: if not mysql_write_switch: wl = seekwritemysql() cluster['writecon'] = MySQLdb.connect(host=wl['host'],user=wl['user'],passwd=wl['passwd'],db=wl['database']) mysql_write_switch = 1 except MySQLdb.Error: print 'mysql connect error' sys.exit(1) print rcmysql wrcursor = cluster['writecon'].cursor() wrcursor.execute("SET NAMES %s" % charset) wrcursor.execute(rcmysql) wrcursor.close() def halt(self,errorcontent): hd = open(error_log,'a+') fcntl.flock(hd,fcntl.LOCK_EX) hd.write('%s/t%s%s' % (errorcontent,time.ctime(),os.linesep)) fcntl.flock(hd,fcntl.LOCK_UN) hd.close() class nettpl: '''forking network model''' def __init__(self,host,port): self.__host = host self.__port = port def server(self): sk = socket.socket(socket.AF_INET,socket.SOCK_STREAM) sk.bind((self.__host,self.__port)) sk.listen(1) global mysql_switch while True: try: clientsk,clientaddr = sk.accept() except socket.error: continue except KeyboardInterrupt: print "[yhm]angel stop" sys.exit(4) signal.signal(signal.SIGCHLD,reap) father = os.fork() if father: clientsk.close() continue else: sk.close() try: while True: clientdata = clientsk.recv(4096) if not len(clientdata):break #callback class myhandler = nettpl_content(clientsk) myhandler.myhandler(clientdata) #except: #traceback.print_exc() finally: print 'complete its work' sys.exit(1) network = nettpl('localhost',9009)#端口默认定义是9009 network.server()

 

php封装好的客户端：

<?php class angel{ const SEND_FLTAG = MSG_DONTROUTE; private $socket; public function connect($host,$port){ $this->socket = socket_create(AF_INET,SOCK_STREAM,SOL_TCP); socket_connect($this->socket,$host,$port); } public function query($sql){ $sqldata = ''; $sqlreturnlen = 999999999; socket_send($this->socket,$sql,strlen($sql),MSG_WAITALL); $data = socket_read($this->socket,$sqlreturnlen); $sqldata .= $data; return $sqldata; } public function fetch_array($query){ if(($unquery = @unserialize($query))){ return $unquery; }else{ exit($query); } } public function close(){ socket_close($this->socket); } } $sql = "select * from cdb_posts limit 20"; $angel = new angel(); $angel->connect('127.0.0.1',9009); print_r($angel->fetch_array($angel->query($sql))); print_r($angel->fetch_array($angel->query($sql))); print_r($angel->fetch_array($angel->query($sql))); print_r($angel->fetch_array($angel->query($sql))); print_r($angel->fetch_array($angel->query($sql))); print_r($angel->fetch_array($angel->query($sql))); print_r($angel->fetch_array($angel->query($sql))); ?>

 

 

php客户端返回的结果是数组，PHP使用十分方便：

 

PHP客户端返回的结果： Array ( [1] => Array ( [status] => 0 [parseurloff] => 0 [htmlon] => 0 [author] => 大海在呼唤 [attachment] => 0 [dateline] => 1052838851 [useip] => 219.159.158.122 [pid] => 1482 [rate] => 0 [invisible] => 0 [authorid] => 169 [bbcodeoff] => 0 [smileyoff] => 0 [fid] => 11 [tid] => 523 [ratetimes] => 0 [message] => 我用电信发的PUTIAN猫（居然是不带路由得）＋自购的4口路由器，感觉还不错。 [subject] => [anonymous] => 0 [usesig] => 1 [first] => 0 ) [2] => Array ( [status] => 0 [parseurloff] => 0 [htmlon] => 0 [author] => 小娜 [attachment] => 0 [dateline] => 1060709851 [useip] => 219.159.192.4 [pid] => 49623 [rate] => 0 [invisible] => 0 [authorid] => 295 [bbcodeoff] => 0 [smileyoff] => 0 [fid] => 32 [tid] => 5872 [ratetimes] => 0 [message] => 后记： 建议喜欢吃牛肉的朋友不妨去尝尝一下花溪牛肉粉。地址如下：三中门口右侧。螺丝粉店是在左侧。 不说了，流口水中~~~~突然好想问那间牛肉粉店的老板要点广告费，这样就可以多吃几份牛肉了。 不行了~~口水淹了键盘啦~~5555找谁赔？？？？？ :o:o:o [subject] => [anonymous] => 0 [usesig] => 1 [first] => 0 ) [3] => Array ( [status] => 0 [parseurloff] => 0 [htmlon] => 0 [author] => happyboy [attachment] => 0 [dateline] => 1062520065 [useip] => 220.173.228.34 [pid] => 71298 [rate] => 0 [invisible] => 0 [authorid] => 959 [bbcodeoff] => 0 [smileyoff] => 0 [fid] => 18 [tid] => 7320 [ratetimes] => 0 [message] => 官商不愁没吃的，他还会进取吗？ [subject] => [anonymous] => 0 [usesig] => 0 [first] => 0 ) [4] => Array ( [status] => 0 [parseurloff] => 0 [htmlon] => 0 [author] => 不空成就 [attachment] => 0 [dateline] => 1062520105 [useip] => 220.173.219.116 [pid] => 71299 [rate] => 0 [invisible] => 0 [authorid] => 111 [bbcodeoff] => 0 [smileyoff] => 0 [fid] => 40 [tid] => 7482 [ratetimes] => 0 [message] => 北海也差点发生这样的事，在外沙那里，后来劝开了，当时拿的是煤气灌来点！ [subject] => [anonymous] => 0 [usesig] => 1 [first] => 0 ) [5]