ActiveMQ笔记(3):基于Networks of Brokers的HA方案

上一篇介绍了基于ZK的ActiveMQ HA方案,虽然理解起来比较容易,但是有二个不足:

1)  占用的节点数过多,1个zk集群至少3个节点,1个activemq集群也至少得3个节点,但其实正常运行时,只有一个master节点在对外响应,换句话说,花6个节点的成本只为了保证1个activemq master节点的高可用,太浪费资源了。

2)  性能下降太明显,比起单节点的activemq,性能下降了近1个数量级。

这一篇将介绍基于networks of brokers的HA方案,不需要借助zk等第3方组件,只需要2个activemq节点就能达到类似效果,进入正题之前,先来简单谈谈Broker这个概念。

Broker一词的原意是『经纪人、中间人』,用在ActiveMQ的构架中,即:Broker作为Producer与Consumer的中间人(或代理人),生产者不用知道消费者在哪里、如何消费这些细节,只要将消息扔给中间人Broker即可,类似的,消费者也不用关心消息是从哪个生产者过来的,它只知道这是从Broker那里拿来的,如果画一张图来描述,就是下面这样(引用自本文最后参考文章中的图片)

 

那么,当生产者将消息发给Broker时,会发生什么?下图描述的就是这个过程:

1) 生产者将消息发给Broker

2) Broker将消息落地存储

3) 然后给生产者反馈:事情我已经办妥了!

继续,再来看看消费者又是如何跟Broker打交道的:

1) Broker将接收到的消息,从db中取出

2) 然后发送给消费者

3) 如果消费者使用的是自动确认模式(即:Session.AUTO_ACKNOWLEDGE),则Consumer会马上告诉Broker:ok,消息我已经收到了。

4) 然后进行自己的业务处理

5) Broker一旦收到确认,将会马上更新消息的状态为已消费(或直接删除,取决于持久化的实现机制)(注:虽然图中步骤5排在步骤4之后,但是步骤4、5几乎是同时发生的)

在一些大型应用中,如果一个Broker出现性能瓶颈抗不住压力,可能会拆分成多个Broker,如下图所示:

(注:上图中箭头的方法并非数据流向,而应该理解成调用关系,即:Producer调用Broker1,Consumer调用Broker2...)

Producer将消息发送给Broker1,而Consumer从另一个Broker2接收消息,有点类似数据库读写分离的意思,这样系统的性能可以提升一定程度的提升,但是问题来了,Broker1上的消息,如何"同步"(见下面的注释)到Broker2呢,这就依赖networkConnector的配置。

注:同步这个词用在这里可能不太准确,但也找不到一个更精确的词来描述,实际上,二个broker用上述机制组建成小集群后,如果生产者连接到broker1,消费者连接到broker2,当消息发送到broker1后,broker1不会将该消息复制一份到broker2,而是等消费者从broker2上消费该消息时,这条消息才从broker1取到broker2上,相当于此时broker2是消费者,从broker1消费了一条消息,然后broker2上就有这条消息了,最终消费者才能broker2上拿到这条消息。

 1 <beans
 2         xmlns="http://www.springframework.org/schema/beans"
 3         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 4         xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
 5   http://activemq.apache.org/schema/core http://activemq.apache.org/schema/core/activemq-core.xsd">
 6 
 7   <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
 8     <property name="locations">
 9       <value>file:${activemq.conf}/credentials.properties</value>
10     </property>
11   </bean>
12 
13   <broker xmlns="http://activemq.apache.org/schema/core" brokerName="activemq-1">
14     <networkConnectors>
15       <networkConnector uri="static:(tcp://127.0.0.1:61626)"/>
16     </networkConnectors>
17     <persistenceAdapter>
18       <kahaDB directory="${activemq.data}/kahadb"/>
19     </persistenceAdapter>
20     <transportConnectors>
21       <transportConnector name="openwire"
22                           uri="tcp://0.0.0.0:61616?maximumConnections=1000&amp;wireFormat.maxFrameSize=104857600"/>
23     </transportConnectors>
24   </broker>
25 
26   <import resource="jetty.xml"/>
27 </beans>
View Code

注意:14-16行及21-22行,该Broker对外暴露61616端口,同时"连接"到61626端口(即另1个broker),最终的效果相当于,如果有producer把消息发到61616(broker1),则从另一个broker(61626端口)上也能消费这条消息。

明白这些基本原理后,在61626对应的activemq上,也做类似的配置,只不过"连接方向"正好相反,参考以下配置:

 1 <beans
 2         xmlns="http://www.springframework.org/schema/beans"
 3         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 4         xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
 5   http://activemq.apache.org/schema/core http://activemq.apache.org/schema/core/activemq-core.xsd">
 6 
 7     <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
 8         <property name="locations">
 9             <value>file:${activemq.conf}/credentials.properties</value>
10         </property>
11     </bean>
12 
13     <broker xmlns="http://activemq.apache.org/schema/core" brokerName="activemq-2">
14         <networkConnectors>
15             <networkConnector uri="static:(tcp://127.0.0.1:61616)"/>
16         </networkConnectors>
17         <persistenceAdapter>
18             <kahaDB directory="${activemq.data}/kahadb"/>
19         </persistenceAdapter>
20         <transportConnectors>
21             <transportConnector name="openwire"
22                                 uri="tcp://0.0.0.0:61626?maximumConnections=1000&amp;wireFormat.maxFrameSize=104857600"/>
23         </transportConnectors>
24     </broker>
25 
26     <import resource="jetty.xml"/>
27 </beans>
View Code

(注:如果希望2个activemq上都能访问admin管理界面,jetty.xml中的端口要修改,不要冲突)

这样,activemq-1与activemq-2这二个broker就互为主备,发给你的消息会同步到我,发给我的消息也会同步到你,实现了HA,示意图如下:

Producer与Consumer连接到activemq时,配置文件可以这么写:

1 <bean id="jmsFactory" class="org.apache.activemq.pool.PooledConnectionFactory" destroy-method="stop">
2     <property name="connectionFactory">
3         <bean class="org.apache.activemq.ActiveMQConnectionFactory">
4             <!--broker服务的地址-->
5             <property name="brokerURL" value="failover:(tcp://localhost:61616,tcp://localhost:61626)"/>
6             ...
7         </bean>
8     </property>
9 </bean>

这种HA方案的优点是占用的节点数更少(只需要2个节点),而且2个broker都可以响应消息的接收与发送,性能比zookeeper方案要好一些。

最后,再给一个简化配置的技巧,以上述的2节点HA方案中,二个activemq的配置文件都要加networkConnector配置,如果想减轻配置的工作量,也可以只在其中一个activemq设置,参考以下片段:

    <networkConnectors>
      <networkConnector uri="static:(tcp://127.0.0.1:61626)" duplex="true"/>
    </networkConnectors>

即:在61616这个activemq的配置文件中,添加networkConnector时,增加duplex="true",也就是双工通讯的意思,这样61616与61626这二个activemq上的broker就建立了双向通讯连接,另一个activemq上就无需额外配置了(注:如果在61626上配置了,反而会报错)

参考文章:

http://www.jakubkorab.net/2011/11/understanding-activemq-broker-networks.html

http://activemq.apache.org/networks-of-brokers.html

 

最后贴二段程序运行的输出日志,以说明同步机制的正确性,打消回复中“大鹏520”的顾虑:

背景: *.*.*.15 与 *.*.*.16 作为HA(双主)的activemq集群,发送程序只连接到15发消息,然后退出。 接收程序只从16上收消息,如果收到了,表明15上的消息同步到16。

下面是发送程序的输出片段:(注意输出日志中关于IP的部分,这是只连接到*.*.*.[b]15[/b]上发送的) (注:部分敏感信息,比如真实IP前缀,公司package名,用*代替了)

14:53:09,996 <*.DemoSender> INFO [main]: 准备发送消息...
14:53:10,270 <org.apache.activemq.transport.WireFormatNegotiator> DEBUG [main]: Sending: WireFormatInfo { version=11, properties={TcpNoDelayEnabled=true, SizePrefixDisabled=false, CacheSize=1024, StackTraceEnabled=true, CacheEnabled=true, TightEncodingEnabled=true, MaxFrameSize=9223372036854775807, Host=*.*.*.15, MaxInactivityDuration=30000, MaxInactivityDurationInitalDelay=10000}, magic=[A,c,t,i,v,e,M,Q]}
14:53:10,306 <org.apache.activemq.transport.InactivityMonitor> DEBUG [ActiveMQ Transport: tcp:///*.*.*.15:61616@50616]: Using min of local: WireFormatInfo { version=11, properties={TcpNoDelayEnabled=true, SizePrefixDisabled=false, CacheSize=1024, StackTraceEnabled=true, CacheEnabled=true, TightEncodingEnabled=true, MaxFrameSize=9223372036854775807, Host=*.*.*.15, MaxInactivityDuration=30000, MaxInactivityDurationInitalDelay=10000}, magic=[A,c,t,i,v,e,M,Q]} and remote: WireFormatInfo { version=11, properties={TcpNoDelayEnabled=true, SizePrefixDisabled=false, CacheSize=1024, StackTraceEnabled=true, CacheEnabled=true, TightEncodingEnabled=true, MaxFrameSize=104857600, MaxInactivityDuration=30000, MaxInactivityDurationInitalDelay=10000}, magic=[A,c,t,i,v,e,M,Q]}
14:53:10,306 <org.apache.activemq.transport.WireFormatNegotiator> DEBUG [ActiveMQ Transport: tcp:///*.*.*.15:61616@50616]: Received WireFormat: WireFormatInfo { version=11, properties={TcpNoDelayEnabled=true, SizePrefixDisabled=false, CacheSize=1024, StackTraceEnabled=true, CacheEnabled=true, TightEncodingEnabled=true, MaxFrameSize=104857600, MaxInactivityDuration=30000, MaxInactivityDurationInitalDelay=10000}, magic=[A,c,t,i,v,e,M,Q]}
14:53:10,306 <org.apache.activemq.transport.WireFormatNegotiator> DEBUG [ActiveMQ Transport: tcp:///*.*.*.15:61616@50616]: tcp:///*.*.*.15:61616@50616 before negotiation: OpenWireFormat{version=11, cacheEnabled=false, stackTraceEnabled=false, tightEncodingEnabled=false, sizePrefixDisabled=false, maxFrameSize=9223372036854775807}
14:53:10,307 <org.apache.activemq.transport.WireFormatNegotiator> DEBUG [ActiveMQ Transport: tcp:///*.*.*.15:61616@50616]: tcp:///*.*.*.15:61616@50616 after negotiation: OpenWireFormat{version=11, cacheEnabled=true, stackTraceEnabled=true, tightEncodingEnabled=true, sizePrefixDisabled=false, maxFrameSize=104857600}
14:53:10,416 <org.springframework.jms.core.JmsTemplate> DEBUG [main]: Executing callback on JMS Session: PooledSession { ActiveMQSession {id=ID:yangjunmings-MacBook-Pro.local-50615-1461480790088-1:1:1,started=false} java.lang.Object@5a56cdac }
14:53:10,471 <org.springframework.jms.core.JmsTemplate> DEBUG [main]: Sending created message: ActiveMQTextMessage {commandId = 0, responseRequired = false, messageId = null, originalDestination = null, originalTransactionId = null, producerId = null, destination = null, transactionId = null, expiration = 0, timestamp = 0, arrival = 0, brokerInTime = 0, brokerOutTime = 0, correlationId = null, replyTo = null, persistent = false, type = null, priority = 0, groupID = null, groupSequence = 0, targetConsumerId = null, compressed = false, userID = null, content = null, marshalledProperties = null, dataStructure = null, redeliveryCounter = 0, size = 0, properties = null, readOnlyProperties = false, readOnlyBody = false, droppable = false, jmsXGroupFirstForConsumer = false, text = message test:0}
14:53:10,516 <*.DemoSender> INFO [main]: 消息0发送完成!
14:53:11,520 <org.springframework.jms.core.JmsTemplate> DEBUG [main]: Executing callback on JMS Session: PooledSession { ActiveMQSession {id=ID:yangjunmings-MacBook-Pro.local-50615-1461480790088-1:1:1,started=false} java.lang.Object@5a56cdac }
14:53:11,521 <org.springframework.jms.core.JmsTemplate> DEBUG [main]: Sending created message: ActiveMQTextMessage {commandId = 0, responseRequired = false, messageId = null, originalDestination = null, originalTransactionId = null, producerId = null, destination = null, transactionId = null, expiration = 0, timestamp = 0, arrival = 0, brokerInTime = 0, brokerOutTime = 0, correlationId = null, replyTo = null, persistent = false, type = null, priority = 0, groupID = null, groupSequence = 0, targetConsumerId = null, compressed = false, userID = null, content = null, marshalledProperties = null, dataStructure = null, redeliveryCounter = 0, size = 0, properties = null, readOnlyProperties = false, readOnlyBody = false, droppable = false, jmsXGroupFirstForConsumer = false, text = message test:1}

 

运行完以后,关掉发送程序,然后启动接收程序

14:54:40,965 <org.apache.activemq.transport.WireFormatNegotiator> DEBUG [main]: Sending: WireFormatInfo { version=11, properties={TcpNoDelayEnabled=true, SizePrefixDisabled=false, CacheSize=1024, StackTraceEnabled=true, CacheEnabled=true, TightEncodingEnabled=true, MaxFrameSize=9223372036854775807, Host=*.*.*.16, MaxInactivityDuration=30000, MaxInactivityDurationInitalDelay=10000}, magic=[A,c,t,i,v,e,M,Q]}
14:54:41,002 <org.apache.activemq.transport.InactivityMonitor> DEBUG [ActiveMQ Transport: tcp:///*.*.*.16:61616@50642]: Using min of local: WireFormatInfo { version=11, properties={TcpNoDelayEnabled=true, SizePrefixDisabled=false, CacheSize=1024, StackTraceEnabled=true, CacheEnabled=true, TightEncodingEnabled=true, MaxFrameSize=9223372036854775807, Host=*.*.*.16, MaxInactivityDuration=30000, MaxInactivityDurationInitalDelay=10000}, magic=[A,c,t,i,v,e,M,Q]} and remote: WireFormatInfo { version=11, properties={TcpNoDelayEnabled=true, SizePrefixDisabled=false, CacheSize=1024, StackTraceEnabled=true, CacheEnabled=true, TightEncodingEnabled=true, MaxFrameSize=104857600, MaxInactivityDuration=30000, MaxInactivityDurationInitalDelay=10000}, magic=[A,c,t,i,v,e,M,Q]}
14:54:41,003 <org.apache.activemq.transport.WireFormatNegotiator> DEBUG [ActiveMQ Transport: tcp:///*.*.*.16:61616@50642]: Received WireFormat: WireFormatInfo { version=11, properties={TcpNoDelayEnabled=true, SizePrefixDisabled=false, CacheSize=1024, StackTraceEnabled=true, CacheEnabled=true, TightEncodingEnabled=true, MaxFrameSize=104857600, MaxInactivityDuration=30000, MaxInactivityDurationInitalDelay=10000}, magic=[A,c,t,i,v,e,M,Q]}
14:54:41,003 <org.apache.activemq.transport.WireFormatNegotiator> DEBUG [ActiveMQ Transport: tcp:///*.*.*.16:61616@50642]: tcp:///*.*.*.16:61616@50642 before negotiation: OpenWireFormat{version=11, cacheEnabled=false, stackTraceEnabled=false, tightEncodingEnabled=false, sizePrefixDisabled=false, maxFrameSize=9223372036854775807}
14:54:41,004 <org.apache.activemq.transport.WireFormatNegotiator> DEBUG [ActiveMQ Transport: tcp:///*.*.*.16:61616@50642]: tcp:///*.*.*.16:61616@50642 after negotiation: OpenWireFormat{version=11, cacheEnabled=true, stackTraceEnabled=true, tightEncodingEnabled=true, sizePrefixDisabled=false, maxFrameSize=104857600}
14:54:41,163 <org.apache.activemq.thread.TaskRunnerFactory> DEBUG [main]: Initialized TaskRunnerFactory[ActiveMQ Session Task] using ExecutorService: java.util.concurrent.ThreadPoolExecutor@485966cc[Running, pool size = 0, active threads = 0, queued tasks = 0, completed tasks = 0]
14:54:41,181 <*.DemoListener> INFO [ActiveMQ Session Task-1]: message test:0


注意接收程序中IP的部分,这是从*.*.*.[b]16[/b]上接收到的,说明消息已经从 *.*.*.15同步到*.*.*.16上了,否则不可能收到消息。

 

posted @ 2016-03-26 15:19 菩提树下的杨过 阅读(...) 评论(...) 编辑 收藏