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467 lines
19 KiB
HTML
467 lines
19 KiB
HTML
<!doctype html>
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<!-- The Time Machine GitHub pages theme was designed and developed by Jon Rohan, on Feb 7, 2012. -->
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<html>
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<head>
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<meta charset="utf-8">
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<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
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<link rel="stylesheet" href="stylesheets/stylesheet.css" media="screen"/>
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<link rel="stylesheet" href="stylesheets/pygment_trac.css"/>
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<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>
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<script type="text/javascript" src="javascripts/script.js"></script>
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<title>Canal</title>
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<meta name="description" content="阿里巴巴mysql数据库binlog的增量订阅&消费组件">
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<meta name="viewport" content="width=device-width,initial-scale=1">
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</head>
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<body>
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<div class="wrapper">
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<header>
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<h1 class="title">Canal</h1>
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</header>
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<div id="container">
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<p class="tagline">阿里巴巴mysql数据库binlog的增量订阅&消费组件</p>
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<div id="main" role="main">
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<div class="download-bar">
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<div class="inner">
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<a href="https://github.com/otter-projects/canal/tarball/master" class="download-button tar"><span>Download</span></a>
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<a href="https://github.com/otter-projects/canal/zipball/master" class="download-button zip"><span>Download</span></a>
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<a href="https://github.com/otter-projects/canal" class="code">View Canal on GitHub</a>
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</div>
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<span class="blc"></span><span class="trc"></span>
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</div>
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<article class="markdown-body">
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<div>
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<div>
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<p> </p>
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<h1>背景</h1>
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<p> 早期,阿里巴巴B2B公司因为存在杭州和美国双机房部署,存在跨机房同步的业务需求。不过早期的数据库同步业务,主要是基于trigger的方式获取增量变更,不过从2010年开始,阿里系公司开始逐步的尝试基于数据库的日志解析,获取增量变更进行同步,由此衍生出了增量订阅&消费的业务,从此开启了一段新纪元。ps. 目前内部使用的同步,已经支持mysql5.x和oracle部分版本的日志解析</p>
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<p> </p>
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<p>基于日志增量订阅&消费支持的业务:</p>
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<ol>
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<li>数据库镜像</li>
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<li>数据库实时备份</li>
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<li>多级索引 (卖家和买家各自分库索引)</li>
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<li>search build</li>
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<li>业务cache刷新</li>
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<li>价格变化等重要业务消息</li>
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</ol>
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<h1>项目介绍</h1>
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<p> 名称:canal [kə'næl]</p>
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<p> 译意: 水道/管道/沟渠 </p>
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<p> 语言: 纯java开发</p>
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<p> 定位: 基于数据库增量日志解析,提供增量数据订阅&消费,目前主要支持了mysql</p>
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<p> </p>
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<h2>工作原理</h2>
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<h3>mysql主备复制实现</h3>
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<p><img src="http://dl.iteye.com/upload/attachment/0080/3086/468c1a14-e7ad-3290-9d3d-44ac501a7227.jpg" alt=""><br> 从上层来看,复制分成三步:</p>
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<ol>
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<li>master将改变记录到二进制日志(binary log)中(这些记录叫做二进制日志事件,binary log events,可以通过show binlog events进行查看);</li>
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<li>slave将master的binary log events拷贝到它的中继日志(relay log);</li>
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<li>slave重做中继日志中的事件,将改变反映它自己的数据。</li>
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</ol>
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<h3>canal的工作原理:</h3>
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<p><img width="590" src="http://dl.iteye.com/upload/attachment/0080/3107/c87b67ba-394c-3086-9577-9db05be04c95.jpg" alt="" height="273"></p>
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<p>原理相对比较简单:</p>
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<ol>
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<li>canal模拟mysql slave的交互协议,伪装自己为mysql slave,向mysql master发送dump协议</li>
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<li>mysql master收到dump请求,开始推送binary log给slave(也就是canal)</li>
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<li>canal解析binary log对象(原始为byte流)</li>
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</ol>
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<h1>架构</h1>
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<p><img width="548" src="http://dl.iteye.com/upload/attachment/0080/3126/49550085-0cd2-32fa-86a6-f676db5b597b.jpg" alt="" height="238"></p>
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<p>说明:</p>
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<ul>
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<li>server代表一个canal运行实例,对应于一个jvm</li>
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<li>instance对应于一个数据队列 (1个server对应1..n个instance)</li>
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</ul>
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<p>instance模块:</p>
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<ul>
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<li>eventParser (数据源接入,模拟slave协议和master进行交互,协议解析)</li>
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<li>eventSink (Parser和Store链接器,进行数据过滤,加工,分发的工作)</li>
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<li>eventStore (数据存储)</li>
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<li>metaManager (增量订阅&消费信息管理器)</li>
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</ul>
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<h3>数据对象格式:<a href="https://github.com/otter-projects/canal/blob/master/protocol/src/main/java/com/alibaba/otter/canal/protocol/EntryProtocol.proto">EntryProtocol.proto</a>
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</h3>
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<pre name="code">Entry
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Header
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logfileName [binlog文件名]
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logfileOffset [binlog position]
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executeTime [发生的变更]
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schemaName
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tableName
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eventType [insert/update/delete类型]
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entryType [事务头BEGIN/事务尾END/数据ROWDATA]
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storeValue [byte数据,可展开,对应的类型为RowChange]
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RowChange
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isDdl [是否是ddl变更操作,比如create table/drop table]
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sql [具体的ddl sql]
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rowDatas [具体insert/update/delete的变更数据,可为多条,1个binlog event事件可对应多条变更,比如批处理]
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beforeColumns [Column类型的数组]
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afterColumns [Column类型的数组]
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Column
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index
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sqlType [jdbc type]
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name [column name]
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isKey [是否为主键]
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updated [是否发生过变更]
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isNull [值是否为null]
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value [具体的内容,注意为文本]</pre>
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<p>说明:</p>
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<ul>
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<li>可以提供数据库变更前和变更后的字段内容,针对binlog中没有的name,isKey等信息进行补全</li>
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<li>可以提供ddl的变更语句</li>
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</ul>
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<h1>QuickStart</h1>
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<h2>几点说明:(mysql初始化)</h2>
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<p>a. canal的原理是基于mysql binlog技术,所以这里一定需要开启mysql的binlog写入功能,并且配置binlog模式为row. </p>
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<pre name="code">[mysqld]
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log-bin=mysql-bin #添加这一行就ok
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binlog-format=ROW #选择row模式
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server_id=1 #配置mysql replaction需要定义,不能和canal的slaveId重复</pre>
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b. canal的原理是模拟自己为mysql slave,所以这里一定需要做为mysql slave的相关权限.</div>
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<div>
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<pre name="code">CREATE USER canal IDENTIFIED BY 'canal';
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GRANT SELECT, REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'canal'@'%';
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-- GRANT ALL PRIVILEGES ON *.* TO 'canal'@'%' ;
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FLUSH PRIVILEGES;</pre>
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<p>针对已有的账户可通过grants查询权限:</p>
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<h2>启动步骤:</h2>
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<p>1. 下载canal</p>
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<p>下载部署包</p>
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<pre name="code">wget http://canal4mysql.googlecode.com/files/canal.deployer-1.0.0.tar.gz</pre>
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<p>or </p>
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<p>自己编译 </p>
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<pre name="code">git clone git@github.com:otter-projects/canal.git
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cd canal;
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mvn clean install -Dmaven.test.skip -Denv=release</pre>
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<p> 编译完成后,会在根目录下产生target/canal.deployer-$version.tar.gz </p>
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<p> </p>
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<p>2. 解压缩</p>
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<pre name="code">mkdir /tmp/canal
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tar zxvf canal.deployer-1.0.0.tar.gz -C /tmp/canal</pre>
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<p> </p>
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<p> 解压完成后,进入/tmp/canal目录,可以看到如下结构:</p>
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<p> </p>
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<pre name="code">drwxr-xr-x 2 jianghang jianghang 136 2013-02-05 21:51 bin
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drwxr-xr-x 4 jianghang jianghang 160 2013-02-05 21:51 conf
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drwxr-xr-x 2 jianghang jianghang 1.3K 2013-02-05 21:51 lib
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drwxr-xr-x 2 jianghang jianghang 48 2013-02-05 21:29 logs</pre>
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<p> </p>
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<p>3. 配置修改</p>
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<p> </p>
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<p>公用参数: </p>
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<pre name="code">vi conf/canal.properties</pre>
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<pre name="code">#################################################
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######### common argument #############
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#################################################
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canal.id= 1
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canal.address=
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canal.port= 11111
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canal.zkServers=
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# flush data to zk
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canal.zookeeper.flush.period = 1000
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## memory store RingBuffer size, should be Math.pow(2,n)
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canal.instance.memory.buffer.size = 32768
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## detecing config
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canal.instance.detecting.enable = false
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canal.instance.detecting.sql = insert into retl.xdual values(1,now()) on duplicate key update x=now()
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canal.instance.detecting.interval.time = 3
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canal.instance.detecting.retry.threshold = 3
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canal.instance.detecting.heartbeatHaEnable = false
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# support maximum transaction size, more than the size of the transaction will be cut into multiple transactions delivery
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canal.instance.transactionn.size = 1024
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# network config
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canal.instance.network.receiveBufferSize = 16384
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canal.instance.network.sendBufferSize = 16384
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canal.instance.network.soTimeout = 30
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#################################################
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######### destinations #############
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#################################################
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canal.destinations= example
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canal.instance.global.mode = spring
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canal.instance.global.lazy = true ##修改为false,代表立马启动
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#canal.instance.global.manager.address = 127.0.0.1:1099
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canal.instance.global.spring.xml = classpath:spring/memory-instance.xml
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#canal.instance.global.spring.xml = classpath:spring/default-instance.xml</pre>
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<p> </p>
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<p>应用参数:</p>
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<pre name="code">vi conf/example/instance.properties</pre>
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<pre name="code">#################################################
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## mysql serverId
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canal.instance.mysql.slaveId = 1234
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# position info
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canal.instance.master.address = 127.0.0.1:3306 #改成自己的数据库地址
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canal.instance.master.journal.name =
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canal.instance.master.position =
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canal.instance.master.timestamp =
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#canal.instance.standby.address =
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#canal.instance.standby.journal.name =
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#canal.instance.standby.position =
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#canal.instance.standby.timestamp =
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# username/password
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canal.instance.dbUsername = retl #改成自己的数据库信息
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canal.instance.dbPassword = retl #改成自己的数据库信息
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canal.instance.defaultDatabaseName = #改成自己的数据库信息
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canal.instance.connectionCharsetNumber = 33 #改成自己的数据库信息
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canal.instance.connectionCharset = UTF-8 #改成自己的数据库信息
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# table regex
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canal.instance.filter.regex = .*\\..*
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#################################################
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</pre>
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<p> </p>
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<p> </p>
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<p> 说明:</p>
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<ul>
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<li>canal.instance.connectionCharset 代表数据库的编码方式对应到java中的编码类型,比如UTF-8,GBK , ISO-8859-1</li>
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<li>canal.instance.connectionCharsetNumber 代表数据库的编码方式对应mysql中的唯一id,详细的映射关系可查看:com.mysql.jdbc.CharsetMapping.INDEX_TO_CHARSET<br>针对常见的编码:<br>utf-8 <=> 33<br>gb2312 <=> 24<br>gbk <=> 28</li>
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</ul>
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<p>4. 准备启动</p>
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<p> </p>
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<pre name="code">sh bin/startup.sh</pre>
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<p> </p>
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<p>5. 查看日志</p>
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<pre name="code">vi logs/canal/canal.log</pre>
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<pre name="code">2013-02-05 22:45:27.967 [main] INFO com.alibaba.otter.canal.deployer.CanalLauncher - ## start the canal server.
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2013-02-05 22:45:28.113 [main] INFO com.alibaba.otter.canal.deployer.CanalController - ## start the canal server[10.1.29.120:11111]
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2013-02-05 22:45:28.210 [main] INFO com.alibaba.otter.canal.deployer.CanalLauncher - ## the canal server is running now ......</pre>
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<p> </p>
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<p> 具体instance的日志:</p>
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<pre name="code">vi logs/example/example.log</pre>
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<pre name="code">2013-02-05 22:50:45.636 [main] INFO c.a.o.c.i.spring.support.PropertyPlaceholderConfigurer - Loading properties file from class path resource [canal.properties]
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2013-02-05 22:50:45.641 [main] INFO c.a.o.c.i.spring.support.PropertyPlaceholderConfigurer - Loading properties file from class path resource [example/instance.properties]
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2013-02-05 22:50:45.803 [main] INFO c.a.otter.canal.instance.spring.CanalInstanceWithSpring - start CannalInstance for 1-example
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2013-02-05 22:50:45.810 [main] INFO c.a.otter.canal.instance.spring.CanalInstanceWithSpring - start successful....</pre>
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<p> </p>
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<p>6. 关闭</p>
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<pre name="code">sh bin/stop.sh</pre>
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<p> </p>
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<p>it's over. </p>
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</div>
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<h1>ClientExample</h1>
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<p>依赖配置:(目前暂未正式发布到mvn仓库,所以需要各位下载canal源码后手工执行下mvn clean install -Dmaven.test.skip)</p>
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<pre name="code"><dependency>
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<groupId>com.alibaba.otter</groupId>
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<artifactId>canal.client</artifactId>
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<version>1.0.0</version>
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</dependency></pre>
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<p> </p>
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<p>1. 创建mvn标准工程:</p>
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<pre name="code">mvn archetype:create -DgroupId=com.alibaba.otter -DartifactId=canal.sample</pre>
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<p> </p>
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<p>2. 修改pom.xml,添加依赖</p>
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<p> </p>
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<p>3. ClientSample代码</p>
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<pre name="code">package com.alibaba.otter.canal.sample;
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import java.net.InetSocketAddress;
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import java.util.List;
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import com.alibaba.otter.canal.common.utils.AddressUtils;
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import com.alibaba.otter.canal.protocol.Message;
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import com.alibaba.otter.canal.protocol.CanalEntry.Column;
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import com.alibaba.otter.canal.protocol.CanalEntry.Entry;
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import com.alibaba.otter.canal.protocol.CanalEntry.EntryType;
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import com.alibaba.otter.canal.protocol.CanalEntry.EventType;
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import com.alibaba.otter.canal.protocol.CanalEntry.RowChange;
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import com.alibaba.otter.canal.protocol.CanalEntry.RowData;
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public class SimpleCanalClientExample {
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public static void main(String args[]) {
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// 创建链接
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CanalConnector connector = CanalConnectors.newSingleConnector(new InetSocketAddress(AddressUtils.getHostIp(),
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11111), "example", "", "");
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int batchSize = 1000;
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int emptyCount = 0;
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try {
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connector.connect();
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connector.subscribe(".*\\..*");
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connector.rollback();
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int totalEmtryCount = 120;
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while (emptyCount < totalEmtryCount) {
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Message message = connector.getWithoutAck(batchSize); // 获取指定数量的数据
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long batchId = message.getId();
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int size = message.getEntries().size();
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if (batchId == -1 || size == 0) {
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emptyCount++;
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System.out.println("empty count : " + emptyCount);
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try {
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Thread.sleep(1000);
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} catch (InterruptedException e) {
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}
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} else {
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emptyCount = 0;
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// System.out.printf("message[batchId=%s,size=%s] \n", batchId, size);
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printEntry(message.getEntries());
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}
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connector.ack(batchId); // 提交确认
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// connector.rollback(batchId); // 处理失败, 回滚数据
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}
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System.out.println("empty too many times, exit");
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} finally {
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connector.disconnect();
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}
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}
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private static void printEntry(List<Entry> entrys) {
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for (Entry entry : entrys) {
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if (entry.getEntryType() == EntryType.TRANSACTIONBEGIN || entry.getEntryType() == EntryType.TRANSACTIONEND) {
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continue;
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}
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RowChange rowChage = null;
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try {
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rowChage = RowChange.parseFrom(entry.getStoreValue());
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} catch (Exception e) {
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throw new RuntimeException("ERROR ## parser of eromanga-event has an error , data:" + entry.toString(),
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e);
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}
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EventType eventType = rowChage.getEventType();
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System.out.println(String.format("================> binlog[%s:%s] , name[%s,%s] , eventType : %s",
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entry.getHeader().getLogfileName(), entry.getHeader().getLogfileOffset(),
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entry.getHeader().getSchemaName(), entry.getHeader().getTableName(),
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eventType));
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for (RowData rowData : rowChage.getRowDatasList()) {
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if (eventType == EventType.DELETE) {
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printColumn(rowData.getBeforeColumnsList());
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} else if (eventType == EventType.INSERT) {
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printColumn(rowData.getAfterColumnsList());
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} else {
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System.out.println("-------> before");
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printColumn(rowData.getBeforeColumnsList());
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System.out.println("-------> after");
|
||
printColumn(rowData.getAfterColumnsList());
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
private static void printColumn(List<Column> columns) {
|
||
for (Column column : columns) {
|
||
System.out.println(column.getName() + " : " + column.getValue() + " update=" + column.getUpdated());
|
||
}
|
||
}
|
||
}</pre>
|
||
|
||
<p> </p>
|
||
|
||
<p>4. 运行Client</p>
|
||
|
||
<p>首先启动Canal Server,可参加QuickStart : <a href="/blogs/1796070">http://agapple.iteye.com/blogs/1796070</a></p>
|
||
|
||
<p>启动Canal Client后,可以从控制台从看到类似消息:</p>
|
||
|
||
<pre name="code">empty count : 1
|
||
empty count : 2
|
||
empty count : 3
|
||
empty count : 4</pre>
|
||
|
||
<p> 此时代表当前数据库无变更数据</p>
|
||
|
||
<p> </p>
|
||
|
||
<p>5. 触发数据库变更</p>
|
||
|
||
<pre name="code">mysql> use test;
|
||
Database changed
|
||
mysql> CREATE TABLE `xdual` (
|
||
-> `ID` int(11) NOT NULL AUTO_INCREMENT,
|
||
-> `X` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
|
||
-> PRIMARY KEY (`ID`)
|
||
-> ) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8 ;
|
||
Query OK, 0 rows affected (0.06 sec)
|
||
|
||
mysql> insert into xdual(id,x) values(null,now());Query OK, 1 row affected (0.06 sec)</pre>
|
||
|
||
<p> </p>
|
||
|
||
<p>可以从控制台中看到:</p>
|
||
|
||
<pre name="code">empty count : 1
|
||
empty count : 2
|
||
empty count : 3
|
||
empty count : 4
|
||
================> binlog[mysql-bin.001946:313661577] , name[test,xdual] , eventType : INSERT
|
||
ID : 4 update=true
|
||
X : 2013-02-05 23:29:46 update=true</pre>
|
||
|
||
<p> </p>
|
||
|
||
<h2>最后:</h2>
|
||
|
||
<p> 整个代码在附件中可以下载,如有问题可及时联系。 </p>
|
||
|
||
<p></p>
|
||
</div>
|
||
|
||
<p></p><div>
|
||
<a href="http://dl.iteye.com/topics/download/7a893f19-bafb-313a-8a7a-e371a4265ad9">canal.sample.tar.gz</a> (2.2 KB)
|
||
</div>
|
||
</article>
|
||
</div>
|
||
</div>
|
||
<footer>
|
||
<div class="owner">
|
||
<p><a href="https://github.com/otter-projects" class="avatar"><img src="https://secure.gravatar.com/avatar/c43c6a524c0265e6d2b30568664c00fb?s=30&d=https://a248.e.akamai.net/assets.github.com%2Fimages%2Fgravatars%2Fgravatar-user-420.png" width="48" height="48"/></a> <a href="https://github.com/otter-projects">otter-projects</a> maintains <a href="https://github.com/otter-projects/canal">Canal</a></p>
|
||
|
||
|
||
</div>
|
||
<div class="creds">
|
||
<small>This page generated using <a href="https://pages.github.com/">GitHub Pages</a><br/>theme by <a href="http://twitter.com/jonrohan/">Jon Rohan</a></small>
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<a href="#top">Scroll to top</a>
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