读写分离Amoeba

本想采用Mysql Proxy来实现读写分离，奈何其使用的lua脚本着实让人头痛，最后决定采用国人开发的开源数据库代理中间件Amoeba。使用Amoeba，只需要简单的xml配置，就可以很容易地实现读写分离。

Amoeba处于应用程序和数据库服务器之间，充当一个中间代理层。其支持负载均衡、高可用性、Query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。功能很强大。

Amoeba默认的端口为8066，实现了Mysql协议。应用程序中只需要修改一个数据库连接就可以实现采用Amoeba来代理数据库访问。比如：Java应用中，假如你原来的jdbc连接字符串为：jdbc:mysql://192.168.168.42:3306/minishop，那么现在，你想使用Amoeba作为数据库访问代理，则只需要将上面连接字符串改为如下(假如Amoeba所在机子IP为192.168.168.88)：jdbc:mysql://192.168.168.88:8066/minishop。Amoeba透明性做的很赞。

主要还是配置Amoeda，但是配置也是相当的简单。基本只需要配置两个文件：confdbServers.xml和confamoeba.xml。配置中各项的含义，可以参考amoeda中文指南，这里不做过多解释。仅记录下配置。

dbServers.xml主要配置

<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 configuration:
             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="manager">${defaultManager}</property>
            <property name="sendBufferSize">64</property>
            <property name="receiveBufferSize">128</property>
                
            <!-- mysql port -->
            <property name="port">3306</property>
            
            <!-- mysql schema -->
            <property name="schema">minishop</property>
            
            <!-- mysql user -->
            <property name="user">chenjie</property>
            
            <!--  mysql password -->
            <property name="password">chenjie</property>

        </factoryConfig>

        <poolConfig class="com.meidusa.amoeba.net.poolable.PoolableObjectPool">
            <property name="maxActive">500</property>
            <property name="maxIdle">500</property>
            <property name="minIdle">10</property>
            <property name="minEvictableIdleTimeMillis">600000</property>
            <property name="timeBetweenEvictionRunsMillis">600000</property>
            <property name="testOnBorrow">true</property>
            <property name="testWhileIdle">true</property>
        </poolConfig>
    </dbServer>

    <dbServer name="master"  parent="abstractServer">
        <factoryConfig>
            <!-- mysql ip -->
            <property name="ipAddress">192.168.168.253</property>
        </factoryConfig>
    </dbServer>

    <dbServer name="slave1"  parent="abstractServer">
        <factoryConfig>
            <!-- mysql ip -->
            <property name="ipAddress">192.168.168.119</property>
        </factoryConfig>
    </dbServer>

    <dbServer name="slave2"  parent="abstractServer">
        <factoryConfig>
            <!-- mysql ip -->
            <property name="ipAddress">192.168.168.251</property>

        </factoryConfig>
    </dbServer>
    
    <dbServer name="multiPool" 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">slave1,slave2</property>
        </poolConfig>
    </dbServer>
        
</amoeba:dbServers>

<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.net.ServerableConnectionManager">
            <!-- port -->
            <property name="port">8066</property>
            
            <!-- bind ipAddress -->

            <property name="ipAddress">192.168.168.253</property>

            
            <property name="manager">${clientConnectioneManager}</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="authenticator">
                <bean class="com.meidusa.amoeba.mysql.server.MysqlClientAuthenticator">
                    
                    <property name="user">chenjie</property>
                    
                    <property name="password">chenjie</property>
                    
                    <property name="filter">
                        <bean class="com.meidusa.amoeba.server.IPAccessController">
                            <property name="ipFile">${amoeba.home}/conf/access_list.conf</property>
                        </bean>
                    </property>
                </bean>
            </property>
            
        </service>
        
        <!-- server class must implements com.meidusa.amoeba.service.Service -->
        <service name="Amoeba Monitor Server" class="com.meidusa.amoeba.monitor.MonitorServer">
            <!-- port -->
            <!--  default value: random number
            <property name="port">9066</property>
            -->
            <!-- bind ipAddress -->
            <property name="ipAddress">127.0.0.1</property>
            <property name="daemon">true</property>
            <property name="manager">${clientConnectioneManager}</property>
            <property name="connectionFactory">
                <bean class="com.meidusa.amoeba.monitor.net.MonitorClientConnectionFactory"></bean>
            </property>
            
        </service>
        
        <runtime class="com.meidusa.amoeba.mysql.context.MysqlRuntimeContext">
            <!-- proxy server net IO Read thread size -->
            <property name="readThreadPoolSize">20</property>
            
            <!-- proxy server client process thread size -->
            <property name="clientSideThreadPoolSize">30</property>
            
            <!-- mysql server data packet process thread size -->
            <property name="serverSideThreadPoolSize">30</property>
            
            <!-- per connection cache prepared statement size  -->
            <property name="statementCacheSize">500</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="clientConnectioneManager" class="com.meidusa.amoeba.net.MultiConnectionManagerWrapper">
            <property name="subManagerClassName">com.meidusa.amoeba.net.ConnectionManager</property>
            <!-- 
              default value is avaliable Processors 
            <property name="processors">5</property>
             -->
        </connectionManager>
        <connectionManager name="defaultManager" class="com.meidusa.amoeba.net.MultiConnectionManagerWrapper">
            <property name="subManagerClassName">com.meidusa.amoeba.net.AuthingableConnectionManager</property>
            
            <!-- 
              default value is avaliable Processors 
            <property name="processors">5</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">master</property>
        

        <property name="writePool">master</property>
        <property name="readPool">multiPool</property>

        <property name="needParse">true</property>
    </queryRouter>
</amoeba:configuration>

至此，Mysql主从热备和读写分离配置完毕。但是，具体应用到生产环境究竟如何，还有待测试和考察。后来测试一主多从，又加入了一台Mysql从数据库服务器，这就是为什么上面amoeba配置中多了一个IP为119的原因。