dubbo服務+Spring事務+AOP動態數據源切換 出錯

1：問題描述，以及分析

        項目用了spring數據源動態切換，服務用的是dubbo。在運行一段時間后程序異常,更新操作沒有切換到主庫上。

這個問題在先調用讀操作后再調用寫操作會出現。

經日志分析原因：

第一：當程序運行一段時間后調用duboo服務時..([DubboServerHandler-192.168.1.106:20880-thread-199] [DubboServerHandler-192.168.1.106:20880-thread-200]) dubbo服務默認最大200線程(超過200個線程以后服務不會創建新的線程了)，讀操作與寫操作有可能會在一個線程里（讀操作的事務propagation是supports,寫是required），當這種情況出現時MethodBeforeAdvice.before先執行，DataSourceSwitcher.setSlave()被調用，然后DynamicDataSource.determineCurrentLookupKey（此方法調用contextHolder.get獲取數據源的key）被調用，此時數據源指向從庫也就是只讀庫。當讀操作執行完成后，dubbo在同一個線程(thead-200)里執行更新的操作（比如以update,insert開頭的服務方法），這時會先執行DynamicDataSource.determineCurrentLookupKey，指向的是讀庫，然后執行MethodBeforeAdvice.before，DataSourceSwitcher.setMaster()被調用，注意，這時DynamicDataSource.determineCurrentLookupKey不會被再次調用，所以這時數據源仍然指向讀庫，異常發生了。(寫從庫了)

      DynamicDataSource.determineCurrentLookupKey 與DataSourceSwitcher.setXXX()方法的執行順序是導致問題的關鍵，這個跟事務的advice與動態設置數據源的advice執行順序有關.

2：application.xml配置

<bean id="parentDataSource" class="org.apache.commons.dbcp2.BasicDataSource">
    <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
    <property name="initialSize" value="20"/>
    <property name="maxTotal" value="50"/>
    <property name="maxIdle" value="10"/>
    <property name="testOnBorrow" value="true"/>
    <property name="testWhileIdle" value="true"/>
    <property name="testOnReturn" value="true"/>
    <property name="defaultAutoCommit" value="false"/>
</bean>
<!-- 主數據源-->
<bean id="masterDataSource" parent="parentDataSource">
    <property name="url" value="jdbc:mysql://192.168.60.45:13306/ac_vote?autoReconnect=true&amp;useSSL=false"/>
    <property name="username" value="data"/>
    <property name="password" value="acfundata"/>
</bean>
<!-- 從數據源-->
<bean id="slaveDataSource" parent="parentDataSource">
    <property name="url" value="jdbc:mysql://192.168.60.45:23306/ac_vote?autoReconnect=true&amp;useSSL=false"/>
    <property name="username" value="data"/>
    <property name="password" value="acfundata"/>
</bean>
<!-- 配置自定義動態數據源-->
<bean id="dataSource" class="tv.acfun.service.common.database.DynamicDataSource">
    <property name="targetDataSources">
        <map key-type="java.lang.String">
            <entry key="slave" value-ref="slaveDataSource" />
            <entry key="master" value-ref="masterDataSource" />
        </map>
    </property>
    <property name="defaultTargetDataSource" ref="masterDataSource" />
</bean>

<!--開啟自動代理功能 true使用CGLIB   -->
<aop:aspectj-autoproxy proxy-target-class="true"/>
<!-- 聲明AOP 切換數據源通知 類中加@Component 自動掃描xml中不用配<bean>了
<bean id="dataSourceAdvice" class="tv.acfun.service.vote.aop.DataSourceAdvice" />
 -->

<!-- 配置通知和切點 注意這個一定要配置在事務聲明(txAdvice)之前 否則就會出現數據源切換出錯  -->

<aop:config>

    <aop:advisor pointcut="execution(* tv.acfun.service.vote.manager.impl.*ManagerImpl.*(..))" advice-ref="dataSourceAdvice" />

</aop:config>

<!-- 配置事務管理器-->
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <property name="dataSource" ref="dataSource" />
</bean>

方式①
<!--開啟注解式事務掃描 要開啟事務的service實現類中 加上@Transactional注解-->
<tx:annotation-driven/>

方式②(注釋中)
<!--未開啟事務掃描時 需指定aop配置 聲明那些類的哪些方法參與事務--start
<tx:advice id="txAdvice" transaction-manager="transactionManager">
<tx:attributes>
 <tx:method name="add*" propagation="REQUIRED" />
        <tx:method name="create*" propagation="REQUIRED" />
        <tx:method name="save*" propagation="REQUIRED"/>
        <tx:method name="edit*" propagation="REQUIRED" />
        <tx:method name="update*" propagation="REQUIRED" />
        <tx:method name="delete*" propagation="REQUIRED" />
        <tx:method name="remove*" propagation="REQUIRED" />
        <tx:method name="find*" propagation="REQUIRED" read-only="true" />
        <tx:method name="query*" propagation="SUPPORTS" read-only="true" />
        <tx:method name="get*" propagation="SUPPORTS" read-only="true" />
         <!-- 對其它方法進行只讀事務 -->
        <!--<tx:method name="*" propagation="SUPPORTS" read-only="true" />-->
</tx:attributes>
</tx:advice>
<aop:config>
    <aop:advisor
            pointcut="execution(* tv.acfun.service.vote.manager..*Service.*(..))"
            advice-ref="txAdvice" />
    <aop:advisor
            pointcut="execution(* tv.acfun.service.vote.manager..*ServiceImpl.*(..))"
            advice-ref="txAdvice" />
</aop:config>
方式② end     -->

 

3. DataSourceAdvice類

@Slf4j
@Aspect
@Component
public class DataSourceAdvice implements MethodBeforeAdvice, AfterReturningAdvice, ThrowsAdvice {

    // service方法執行之前被調用
public void before(Method method, Object[] args, Object target) throws Throwable {
       log.info("切入點: " + target.getClass().getName() + "類中" + method.getName() + "方法");
       if (method.getName().startsWith("insert") || method.getName().startsWith("create")
         || method.getName().startsWith("save") || method.getName().startsWith("edit")
         || method.getName().startsWith("update") || method.getName().startsWith("delete")
         || method.getName().startsWith("remove")) {
           log.info("切換到: master");
DataSourceSwitcher.setMaster();
} else {
          log.info("切換到: slave");
DataSourceSwitcher.setSlave();
}
}

 // service方法執行完之后被調用
public void afterReturning(Object var1, Method var2, Object[] var3, Object var4) throws Throwable {
         DataSourceSwitcher.setMaster(); // *****  加上這句解決運行數據庫切換問題
}

 // 拋出Exception之后被調用
public void afterThrowing(Method method, Object[] args, Object target, Exception ex) throws Throwable {
     DataSourceSwitcher.setSlave();
log.info("出現異常,切換到: slave");
} 

4. DataSourceSwitcher 類

public class DataSourceSwitcher {

    private static final ThreadLocal contextHolder = new ThreadLocal();

    private static final String DATA_SOURCE_SLAVE = "slave" ;

    public static void setDataSource(String dataSource) {
        Assert.notNull(dataSource, "dataSource cannot be null");
contextHolder.set(dataSource);
}

    public static void setMaster(){
        clearDataSource();
}

    public static void setSlave() {
        setDataSource( DATA_SOURCE_SLAVE);
}

    public static String getDataSource() {
        return (String) contextHolder.get();
}

    public static void clearDataSource() {
        contextHolder.remove();
}
} 

5. DynamicDataSource 類

public class DynamicDataSource extends AbstractRoutingDataSource {

    @Override
protected Object determineCurrentLookupKey() {
        return DataSourceSwitcher.getDataSource();
}

}

和 http://my.oschina.net/mrXhuangyang/blog/500743 這個遇到一樣問題


或者基於注解@Aspect切面

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans.xsd
           http://www.springframework.org/schema/context
           http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd"
       default-autowire="byName">
    <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="locations">
            <list>
                <value>classpath:system.properties</value>
            </list>
        </property>
    </bean>
    <context:component-scan base-package="com.xxx.service.main"/>

    <!-- config mybatis -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <property name="configLocation" value="classpath:/mybatis/mybatis-config.xml"/>
        <property name="typeAliasesPackage" value="com.xxx.service.entity"/>
        <property name="mapperLocations" value="classpath*:/mybatis/*Mapper.xml"/>
    </bean>
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.xxx.service.main.dao"/>
        <property name="annotationClass" value="com.xxx.service.main.dao.MyBatisRepository"/>
    </bean>

    <bean id="parentDataSource" class="org.apache.commons.dbcp2.BasicDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="initialSize" value="20"/>
        <property name="maxTotal" value="50"/>
        <property name="maxIdle" value="10"/>
        <property name="testOnBorrow" value="true"/>
        <property name="testWhileIdle" value="true"/>
        <property name="testOnReturn" value="true"/>
        <property name="defaultAutoCommit" value="false"/>
    </bean>

    <bean id="masterDataSource" parent="parentDataSource">
        <property name="url" value="jdbc:mysql://mysql.xxx.com:3306/system32?useUnicode=true&amp;characterEncoding=UTF-8&amp;zeroDateTimeBehavior=convertToNull&amp;transformedBitIsBoolean=true"/>
        <property name="username" value="cache"/>
        <property name="password" value="test2"/>
    </bean>
    <!-- 從數據源-->
    <bean id="slaveDataSource" parent="parentDataSource">
        <property name="url" value="jdbc:mysql://mysql-slave.xxx.com:3306/system32?useUnicode=true&amp;characterEncoding=UTF-8&amp;zeroDateTimeBehavior=convertToNull&amp;transformedBitIsBoolean=true"/>
        <property name="username" value="cache"/>
        <property name="password" value="test2"/>
    </bean>

    <bean id="dataSource" class="com.xxx.service.common.database.DynamicDataSource">
        <property name="targetDataSources">
            <map key-type="java.lang.String">
                <entry key="slave" value-ref="slaveDataSource" />
            </map>
        </property>
        <property name="defaultTargetDataSource" ref="masterDataSource" />
    </bean>

     <!--開啟@Aspect注解支持-->
     <aop:aspectj-autoproxy/>

    <!--定義事務管理器-->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource" />
    </bean>

    <!-- annotation-driven就是支持事務注解的(@Transaction) -->
    <tx:annotation-driven transaction-manager="transactionManager"/>

    <!-- config redis -->
    <bean id="poolConfig" class="redis.clients.jedis.JedisPoolConfig">
        <property name="maxIdle" value="${spring.redis.pool.max-idle}" />
        <property name="maxTotal" value="${spring.redis.pool.max-active}" />
        <property name="minIdle" value="${spring.redis.pool.min-idle}" />
        <property name="maxWaitMillis" value="${spring.redis.pool.max-wait}" />
    </bean>

    <bean id="connectionFactory" class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory">
        <property name="hostName" value="${spring.redis.host}" />
        <property name="port" value="${spring.redis.port}" />
        <property name="poolConfig" ref="poolConfig" />
    </bean>

    <bean id="stringRedisTemplate" class="org.springframework.data.redis.core.StringRedisTemplate">
        <property name="connectionFactory"   ref="connectionFactory" />
    </bean>
    <bean id="redisTemplate" class="org.springframework.data.redis.core.RedisTemplate">
        <property name="connectionFactory"   ref="connectionFactory" />
        <!-- key的序列化配置,不配置的話key值會有亂碼 -->
        <property name="keySerializer">
            <bean class="org.springframework.data.redis.serializer.StringRedisSerializer" />
        </property>
        <property name="hashKeySerializer">
            <bean class="org.springframework.data.redis.serializer.StringRedisSerializer" />
        </property>
    </bean>

</beans>

@Aspect切面類

package tv.acfun.service.main.aop;

import lombok.extern.slf4j.Slf4j;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.*;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.aop.AfterReturningAdvice;
import org.springframework.aop.MethodBeforeAdvice;
import org.springframework.aop.ThrowsAdvice;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;
import tv.acfun.service.common.database.DataSourceSwitcher;

import java.lang.reflect.Method;

/**
 * @author xxx
 * @date 2016-11-24
 * @what 讀寫分離切面類
 */
@Slf4j
@Component
@Aspect
public  class DataSourceAspect {

    @Pointcut("execution(* com.xxx.service.main.manager.impl.*ManagerImpl.*(..))")
    private void aspectjMethod(){}

    // service方法執行之前被調用
    @Before(value = "aspectjMethod()")
    public void before(JoinPoint joinPoint) throws Throwable {
        MethodSignature methodSignature = (MethodSignature) joinPoint.getSignature();
        Method method = methodSignature.getMethod();
        log.debug("切入點: " + joinPoint.getTarget().getClass().getName() + "類中" + method.getName() + "方法");
        if(method.getName().startsWith("add")
                || method.getName().startsWith("insert")
                || method.getName().startsWith("create")
                || method.getName().startsWith("save")
                || method.getName().startsWith("edit")
                || method.getName().startsWith("update")
                || method.getName().startsWith("delete")
                || method.getName().startsWith("remove")){
            log.debug("切換到: master");
            DataSourceSwitcher.setMaster();
        }else  {
            log.debug("切換到: slave");
            DataSourceSwitcher.setSlave();
        }
    }

}

AOP方式資料:http://www.360doc.com/content/12/0602/15/7656232_215420487.shtml

另外看到一個文章講 

@Order(-1)

DataSourceAdvice前面加上一個Order注解 可以保證 數據源切換通知 在 事務通知前執行.