Question

问题：我们有2或3个应用程序实例。每个实例都有一个生产者和一个消费者。我们必须安排一些过程，为此我们使用常见的spring调度程序。此调度程序生成消息并将它们抛给“Broker”（RabbitMQ）。在我们的例子中，我们处理相同的数据2或3次，因为每个实例都会抛出消息。在第一个生产者抛出消息之前，你会如何阻止实例的生产者呢？

配置：

<!-- RabbitMQ configuration -->
<rabbit:connection-factory
        id="connection" host="${rabbit.host}" port="${rabbit.port}"      username="${rabbit.username}" password="${rabbit.password}"
        channel-cache-size="${rabbit.publisherCacheSize}" virtual-host="${rabbit.virtualHost}" />

<!-- Declare executor pool for worker threads -->
<!-- Ensure that the pool-size is greater than the sum of all number of concurrent consumers from rabbit that use this pool to ensure
     you have enough threads for maximum concurrency. We do this by ensuring that this is 1 plus the size of the connection factory cache
     size for all consumers -->
<task:executor id="worker-pool" keep-alive="60" pool-size="${rabbit.consumerChannelCacheSize}" queue-capacity="1000" rejection-policy="CALLER_RUNS"/>


<!-- Message converter -->
<bean id="baseMessageConverter" class="org.springframework.oxm.jaxb.Jaxb2Marshaller">
    <property name="classesToBeBound" value="com.company.model.Scraper"/>
</bean>

<bean id="messageConverter" class="org.springframework.amqp.support.converter.MarshallingMessageConverter">
    <constructor-arg index="0" ref="baseMessageConverter"/>
</bean>


<!-- *********************************producer*********************************** -->
<!-- Outbound company Events -->
<int:channel id="producerChannelCompany"/>
<int:gateway id="jobcompanyCompleteEventGateway" service-interface="com.company.eventing.companyEventPublisher"
             default-request-channel="producerChannelCompany"
             default-request-timeout="2000"
             error-channel="errors"/>

<amqp:outbound-channel-adapter id="companyEvents.amqpAdapter" channel="producerChannelCompany"
                               exchange-name="${rabbit.queue.topic}"
                               routing-key="${rabbit.queue.routing.key}"
                               amqp-template="psRabbitTemplate"/>

<rabbit:admin id="psRabbitAdmin" connection-factory="connection" />
<rabbit:template id="psRabbitTemplate" channel-transacted="${rabbit.channelTransacted}" encoding="UTF-8" message-converter="messageConverter" connection-factory="connection"/>
<rabbit:topic-exchange id="ps.topic" name="${rabbit.queue.topic}" durable="true" auto-delete="false"/>



<!-- *********************************consumer*********************************** -->
<rabbit:queue id="ps.queue" name="${rabbit.queue}"  auto-delete="false" durable="true" exclusive="false"  />


<!-- Exchange to queue binding -->
<rabbit:topic-exchange id="ps.topic" name="${rabbit.queue.topic}" durable="true" auto-delete="false" >
    <rabbit:bindings>
        <rabbit:binding queue="${rabbit.queue}" pattern="${rabbit.queue.pattern}"></rabbit:binding>
    </rabbit:bindings>
</rabbit:topic-exchange>

<!-- Configuration for consuming company Complete events -->
<amqp:inbound-channel-adapter id="companyAdapter"
                              channel="companyCompleteEventChannel"
                              queue-names="${rabbit.queue}"
                              channel-transacted="${rabbit.channelTransacted}"
                              prefetch-count="${rabbit.prefetchCount}"
                              concurrent-consumers="${rabbit.concurrentConsumers}"
                              connection-factory="connection"
                              message-converter="messageConverter"
                              task-executor="worker-pool"
                              error-channel="errors"/>



<int:channel id="companyCompleteEventChannel"/>
<int:service-activator id="companyCompleteActivator" input-channel="companyCompleteEventChannel"
                       ref="companyEventHandler" method="runScraper"/>

<bean id="jvmLauncher" class="com.app.company.jvm.JvmLauncher" />
<!-- company Event handler -->
<bean id="companyEventHandler" class="com.app.company.eventing.consumer.companyEventHandler" depends-on="jvmLauncher">
    <!--<property name="scriptHelper" ref="scriptHelper"/>-->
    <property name="jvmLauncher" ref="jvmLauncher" />
    <property name="defaultMemoryOptions" value="${company.memory.opts}"/>
    <property name="defaultMemoryRegex" value="${company.memory.regex}"/>
</bean>


<!-- ERRORS -->
<int:channel id="errors"/>
<int:service-activator id="psErrorLogger" input-channel="errors" ref="psloggingHandler"/>

<bean id="psloggingHandler" class="org.springframework.integration.handler.LoggingHandler">
    <constructor-arg index="0" value="DEBUG"></constructor-arg>
    <!-- <property name="loggerName" value="com.app.travelerpayments.loggingHandler"/> -->
</bean>

Answer 1

目前尚不清楚您拥有什么样的体系结构，但如果所有实例都使用来自同一队列的消息，则每条消息只会消耗一次（除非消费者重新排队）。我想，这是在你的情况下使用AMQP电源的最好方法。如果我错过了什么，请澄清你的问题。

使用a-la扇出消息传递，当每个实例都有自己的队列和自己的消息堆栈，并且你想控制自己的消息传递（当然，几乎在所有情况下都是坏主意），为什么不让所有实例听取限制为扇出交换的个人队列，并将此交换用于控制消息。您可以告诉实例何时停止或开始消费，刷新队列，安排重启等等。

注意，您也可以使用主题交换和特定路由键绑定队列，例如“control。*”

我们的想法是发送who is free请求，挑选随机免费工作者并向其发送有效负载。您可以使用特定的路由密钥或仅使用与队列名称相同的路由密钥将有效负载发布到默认交换（默认情况下，队列绑定到与队列名称相同的路由密钥的默认交换，请参阅RabbitMQ文档中的Default Exchange部分）。

Java RabbitMQ + AMQP阻塞生产者一段时间（锁定）

1 个答案: