分布式Hibernate search

分布式 Hibernate Search 支持多个节点Read/Write。在网上找到一篇完整介绍的文章，我粗陋的翻译了一下。原文连接 http://aredko.blogspot.com/2009/12/distributed-hibernate-search-with.html(需要fanqiang)

分布式Hibernate Search与Apache Tomcat6,ActiveMQ 和Spring.今天我将跟大家分享我的经验，以master/slave(s)方式配置分布式Hibernate Search并整合Apache ActiveMQ,Spring,应用程序额容器是Apache Tomcat 6。

怎么工作：
-Hibernate Search 支持使用JMS back-end 和 master/slave(s) 索引进行分布式配置
- mater通过网络共享暴露索引 （例如通过NFS。。。）
- slave(s) 复制mater的索引到本地

版本
- Apache Tomcat 6.0.20
- Hibernate Search 3.1.1 GA
- Apache ActiveMQ 5.3.0
- Spring 2.5.6
- XBean-Spring 3.6

${local.index.dir} - directory to store master index
${master.index.dir} - directory to copy master index to, it's shared network location for replication with slave(s)

Mater索引的配置
Mater的配置稍显复杂。以下是配置属性说明

$(local.index.dir) - 存储mater索引的目录
$(master.index.dir) -拷贝mater索引的目标目录，通过网络定位供slave(s)复制。

首先，为了简单起见，我们将ActiveMQ中介运行在同一台服务器上。因此，我们在WEB-INF/activemq.xml文件中使用简单的嵌入式中介配置。

<beans
 xmlns="http://www.springframework.org/schema/beans"
 xmlns:amq="http://activemq.apache.org/schema/core"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://www.springframework.org/schema/beans
 http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
 http://activemq.apache.org/schema/core
 http://activemq.apache.org/schema/core/activemq-core.xsd">

 <amq:broker brokerName="HibernateSearchBroker">
     <amq:managementContext>
         <amq:managementContext createConnector="false"/>
     </amq:managementContext>

     <amq:transportConnectors>
         <amq:transportConnector uri="tcp://localhost:61616" /> 
     </amq:transportConnectors>
  </amq:broker>

  <amq:queue name="queue/hibernatesearch" physicalName="hibernateSearchQueue" />
</beans>

其次，需要在web application MEAT-INF/context.xml(Tocmat)中配置配置JNDI资源(JMS Connection Factory 和 Quene)

<!-- ActiveMQ ConnectionFactory -->
<Resource
name="jms/ConnectionFactory"
auth="Container"
type="org.apache.activemq.ActiveMQConnectionFactory"
description="JMS Connection Factory"
factory="org.apache.activemq.jndi.JNDIReferenceFactory"
brokerURL="tcp://0.0.0.0:61616?trace=true"
brokerName="HibernateSearchBroker" />

<!-- ActiveMQ HibernateSearch queue -->
<Resource
name="queue/hibernatesearch"
auth="Container" type="org.apache.activemq.command.ActiveMQQueue"
description="Hibernate search queue"
factory="org.apache.activemq.jndi.JNDIReferenceFactory"
physicalName="hibernateSearchQueue" />

接下来在Hibernate.cfg.xml文件中配置Hibernate Search

<property name="hibernate.search.default.directory_provider">org.hibernate.search.store.FSMasterDirectoryProvider</property>
<property name="hibernate.search.default.indexBase">${local.index.dir}</property>
<property name="hibernate.search.default.sourceBase">${master.index.dir}</property>
<property name="hibernate.search.default.refresh">60</property>

Master和slave之间代码的一个重要区别是:master中必须包含实现 AbstractJMSHibernateSearchController 的子类作为监听器，例如

import javax.jms.MessageListener;

import org.hibernate.Session;
import org.hibernate.search.backend.impl.jms.AbstractJMSHibernateSearchController;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class JMSHibernateSearchController
 extends AbstractJMSHibernateSearchController
     implements MessageListener {

 @Override
 protected void cleanSessionIfNeeded(Session session) {
    // clean session here ...     
 }

 @Override
 protected Session getSession() {
    // return new session here ...     
 }
}

最后在Spring的配置文件applicationContext.xml文件中，加入以下配置

<bean id="broker" class="org.apache.activemq.xbean.BrokerFactoryBean">
 <property name="config" value="WEB-INF/activemq.xml" />
 <property name="start" value="true" />
</bean>  

<bean name="jmsConnectionFactory" class="org.springframework.jndi.JndiObjectFactoryBean">
 <property name="jndiName" value="java:comp/env/jms/ConnectionFactory" />
</bean>

<bean name="jmsHibernateSearchQueue" class="org.springframework.jndi.JndiObjectFactoryBean">
 <property name="jndiName" value="java:comp/env/queue/hibernatesearch" />

<bean id="hibernateSearchController" class="<your implementation of AbstractJMSHibernateSearchController>" />

<bean id="jmsContainer" class="org.springframework.jms.listener.DefaultMessageListenerContainer" depends-on="broker">
 <property name="connectionFactory" ref="jmsConnectionFactory"/>
 <property name="destination" ref="jmsHibernateSearchQueue"/>
 <property name="messageListener" ref="hibernateSearchController" />
</bean>

With those configurations in place Hibernate Search master is ready to run.
正确配置好之后，Hibernate Search master就可以运行了。

Slave 索引配置
Slave(s)的配置要简单得多，一下是配置属性说明

${server} - 运行ActiveMQ中介服务器
${lcoal.index.dir} - 存储本地索引的目录(master的拷贝)
${mater.index.share}-挂载mater索引的网络共享目录.

首先，我们需要在网站应用 MEAT-INF/context.xml(Tocmat)中配置配置JNDI资源(JMS Connection Factory 和 Quene)

...
<!-- ActiveMQ ConnectionFactory -->
<Resource
name="jms/ConnectionFactory"
auth="Container"
type="org.apache.activemq.ActiveMQConnectionFactory"
description="JMS Connection Factory"
factory="org.apache.activemq.jndi.JNDIReferenceFactory"
brokerURL="tcp://${server}:61616?trace=true"
brokerName="HibernateSearchBroker" />

<!-- ActiveMQ HibernateSearch queue -->
<Resource
name="queue/hibernatesearch"
auth="Container" type="org.apache.activemq.command.ActiveMQQueue"
description="Hibernate search queue"
factory="org.apache.activemq.jndi.JNDIReferenceFactory"
physicalName="hibernateSearchQueue" />
...

接下来我们需要在hibernate.cfg.xml中配置Hibernate Search

<property name="hibernate.search.default.directory_provider">org.hibernate.search.store.FSSlaveDirectoryProvider</property>
<property name="hibernate.search.default.indexBase">${local.index.dir}</property>
<property name="hibernate.search.default.sourceBase">${master.index.share}</property>
<property name="hibernate.search.default.refresh">60</property>
<property name="hibernate.search.worker.backend">jms</property>
<property name="hibernate.search.worker.jms.connection_factory">java:comp/env/jms/ConnectionFactory</property>
<property name="hibernate.search.worker.jms.queue">java:comp/env/queue/hibernatesearch</property>
<property name="hibernate.search.worker.jndi.java.naming.factory.initial">org.apache.activemq.jndi.ActiveMQInitialContextFactory</property>

配置到此结束

说些关于JUnit测试的题外话.唯一的问题是需要使用Spring JNDI templates模拟JNDI，例如

<bean name="jmsConnectionFactory" class="org.springframework.jndi.JndiObjectFactoryBean">
    <property name="jndiName" value="java:comp/env/jms/ConnectionFactory" />
    <property name="jndiTemplate">
        <bean class="org.springframework.mock.jndi.ExpectedLookupTemplate">
            <constructor-arg index="0" value="java:comp/env/jms/ConnectionFactory" />
            <constructor-arg index="1">
                <bean class="org.apache.activemq.ActiveMQConnectionFactory">
                    <property name="brokerURL">
                        <value>tcp://0.0.0.0:61616</value>
                    </property>
                </bean>
            </constructor-arg>
        </bean>
    </property>
</bean>

<bean name="jmsHibernateSearchQueue" class="org.springframework.jndi.JndiObjectFactoryBean">
    <property name="jndiName" value="java:comp/env/queue/hibernatesearch" />
    <property name="jndiTemplate">
       <bean class="org.springframework.mock.jndi.ExpectedLookupTemplate">
           <constructor-arg index="0" value="java:comp/env/queue/hibernatesearch" />
           <constructor-arg index="1">
               <bean id="jmsHibernateSearchQueue"   class="org.apache.activemq.command.ActiveMQQueue">
                   <constructor-arg value="queue/hibernateSearchQueue"/>
               </bean>               
           </constructor-arg>
       </bean>
    </property>
</bean>