10 读写分离和Amoeba
约 1044 字大约 3 分钟
10 读写分离和Amoeba
一、什么是 amoeba？
Amoeba(变形虫)项目，专注 分布式数据库 proxy 开发。座落与 Client、DB Server(s)之间。对客户端透明。具有负载均衡、高可用性、sql 过滤、读写分离、可路由相关的 query 到目标数据库、可并发请求多台数据库合并结果。
主要解决：
• 降低 数据切分带来的复杂多数据库结构
• 提供切分规则并降低 数据切分规则 给应用带来的影响
• 降低 db 与客户端的连接数
• 读写分离 二、为什么要用 Amoeba
目前要实现 mysql 的主从读写分离，主要有以下几种方案：
1、 通过程序实现，网上很多现成的代码，比较复杂，如果添加从服务器要更改多台服务器的代码。
2、 通过 mysql-proxy 来实现，由于 mysql-proxy 的主从读写分离是通过 lua 脚本来实现，目前 lua 的脚本的开发跟不上节奏，而写没有完美的现成的脚本，因此导致用于生产环境的话风险比较大，据网上很多人说 mysql-proxy 的性能不高。
3、 自己开发接口实现，这种方案门槛高，开发成本高，不是一般的小公司能承担得起。
4、 利用阿里巴巴的开源项目 Amoeba 来实现，具有负载均衡、高可用性、sql 过滤、读写分离、可路由相关的 query 到目标数据库，并且安装配置非常简单。
三、amoeba 安装
1、首先安装 jdk，直接使用 rpm 包安装即可 2、下载 amoeba 对应的版本https://sourceforge.net/projects/amoeba/，直接解压即可 3、配置 amoeba 的配置文件 dbServers.xml
<?xml version="1.0" encoding="gbk"?>
<!DOCTYPE amoeba:dbServers SYSTEM "dbserver.dtd">
<amoeba:dbServers xmlns:amoeba="http://amoeba.meidusa.com/">
<!--Each dbServer needs to be configured into a Pool,If you need to configure multiple dbServer with load balancing that can be simplified by the following configu ration: add attribute with name virtual = "true" in dbServer, but the configuration does not allow the element with name factoryConfig such as 'multiPool' dbServer-->
<dbServer name="abstractServer" abstractive="true">
<factoryConfig class="com.meidusa.amoeba.mysql.net.MysqlServerConnectionFactory">
<property name="connectionManager">${defaultManager}</property>
<property name="sendBufferSize">64</property>
<property name="receiveBufferSize">128</property>
<!-- mysql port -->
<property name="port">3306</property>
<!-- mysql schema -->
<property name="schema">msb</property>
<!-- mysql user -->
<property name="user">root</property>
<property name="password">123</property>
</factoryConfig>
<poolConfig class="com.meidusa.toolkit.common.poolable.PoolableObjectPool">
<property name="maxActive">500</property>
<property name="maxIdle">500</property>
<property name="minIdle">1</property>
<property name="minEvictableIdleTimeMillis">600000</property>
<property name="timeBetweenEvictionRunsMillis">600000</property>
<property name="testOnBorrow">true</property>
<property name="testOnReturn">true</property>
<property name="testWhileIdle">true</property>
</poolConfig>
</dbServer>
<dbServer name="writedb" parent="abstractServer">
<factoryConfig>
<!-- mysql ip -->
<property name="ipAddress">192.168.85.11</property>
</factoryConfig>
</dbServer>
<dbServer name="slave" parent="abstractServer">
<factoryConfig>
<!-- mysql ip -->
<property name="ipAddress">192.168.85.12</property>
</factoryConfig>
</dbServer>
<dbServer name="myslave" virtual="true">
<poolConfig class="com.meidusa.amoeba.server.MultipleServerPool">
<!-- Load balancing strategy: 1=ROUNDROBIN , 2=WEIGHTBASED , 3=HA-->
<property name="loadbalance">1</property>
<!-- Separated by commas,such as: server1,server2,server1 -->
<property name="poolNames">slave</property>
</poolConfig>
</dbServer>
</amoeba:dbServers>
amoeba.xml
<?xml version="1.0" encoding="gbk"?>
<!DOCTYPE amoeba:configuration SYSTEM "amoeba.dtd">
<amoeba:configuration xmlns:amoeba="http://amoeba.meidusa.com/">
<proxy>
<!-- service class must implements com.meidusa.amoeba.service.Service -->
<service name="Amoeba for Mysql" class="com.meidusa.amoeba.mysql.server.MySQLService">
<!-- port -->
<property name="port">8066</property>
<!-- bind ipAddress -->
<!--
<property name="ipAddress">127.0.0.1</property>
-->
<property name="connectionFactory">
<bean class="com.meidusa.amoeba.mysql.net.MysqlClientConnectionFactory">
<property name="sendBufferSize">128</property>
<property name="receiveBufferSize">64</property>
</bean>
</property>
<property name="authenticateProvider">
<bean class="com.meidusa.amoeba.mysql.server.MysqlClientAuthenticator">
<property name="user">root</property>
<property name="password">123</property>
<property name="filter">
<bean class="com.meidusa.toolkit.net.authenticate.server.IPAccessController">
<property name="ipFile">${amoeba.home}/conf/access_list.conf</property>
</bean>
</property>
</bean>
</property>
</service>
<runtime class="com.meidusa.amoeba.mysql.context.MysqlRuntimeContext">
<!-- proxy server client process thread size -->
<property name="executeThreadSize">128</property>
<!-- per connection cache prepared statement size -->
<property name="statementCacheSize">500</property>
<!-- default charset -->
<property name="serverCharset">utf8</property>
<!-- query timeout( default: 60 second , TimeUnit:second) -->
<property name="queryTimeout">60</property>
</runtime>
</proxy>
<!--
Each ConnectionManager will start as thread
manager responsible for the Connection IO read , Death Detection
-->
<connectionManagerList>
<connectionManager name="defaultManager" class="com.meidusa.toolkit.net.MultiConnectionManagerWrapper">
<property name="subManagerClassName">com.meidusa.toolkit.net.AuthingableConnectionManager</property>
</connectionManager>
</connectionManagerList>
<!-- default using file loader -->
<dbServerLoader class="com.meidusa.amoeba.context.DBServerConfigFileLoader">
<property name="configFile">${amoeba.home}/conf/dbServers.xml</property>
</dbServerLoader>
<queryRouter class="com.meidusa.amoeba.mysql.parser.MysqlQueryRouter">
<property name="ruleLoader">
<bean class="com.meidusa.amoeba.route.TableRuleFileLoader">
<property name="ruleFile">${amoeba.home}/conf/rule.xml</property>
<property name="functionFile">${amoeba.home}/conf/ruleFunctionMap.xml</property>
</bean>
</property>
<property name="sqlFunctionFile">${amoeba.home}/conf/functionMap.xml</property>
<property name="LRUMapSize">1500</property>
<property name="defaultPool">writedb</property>
<property name="writePool">writedb</property>
<property name="readPool">myslave</property>
<property name="needParse">true</property>
</queryRouter>
</amoeba:configuration>
4、启动 amoeba
/root/amoeba-mysql-3.0.5-RC/bin/launcher
四、测试 amoeba
--测试的sql
--在安装amoeba的服务器上登录mysql
mysql -h192.168.85.13 -uroot -p123 -P8066
--分别在master、slave、amoeba上登录mysql
use msb
select * from user;
--在amoeba上插入数据
insert into user values(2,2);
--在master和slave上分别查看表中的数据
select * from user;
--将master上的mysql服务停止，继续插入数据会发现插入不成功，但是能够查询
--将master上的msyql服务开启，停止slave上的mysql，发现插入成功，但是不能够查询