为JMS发布者/使用者设置clientID的目的是什么？ [英] What's the Purpose of setting the clientID for JMS publisher / consumer?

问题描述

我了解在为持久主题编写jms主题订户时，我需要设置clientId和订阅名称。

但是在以下情况下设置clientID的目的是什么？发布主题？我见过有人甚至为发布者/使用者设置了客户端ID，但是没有人解释为什么要这样做。

  ConnectionFactory conFactory = this.getConnectionFactory（）; 
连接连接= conFactory.createConnection（）; 
 
 connection.setClientID（ WHATS_MY_PURPOSE）; //为什么从消费者/发布者发布主题时我们需要clientID 
 
 connection.start（）; 
 MessageProducer生产者= session.createProducer（destination）; 
  

解决方案

A clientId 是唯一标识应用程序所必需的。在发布/订阅消息传递模式中使用永久订阅时，这是必须的。如您所知，消息传递提供者在脱机时会缓存发往持久订阅者应用程序的发布。当此类应用程序再次上线时，消息传递提供者必须确定 OK，这与创建持久订阅但由于某种原因而消失的同一应用程序相同。现在又回来了。因此，让我传递在此应用程序消失后发布的所有消息。为了验证它是同一应用程序，消息传递提供程序将应用程序的 clientId 与具有缓存的订阅信息的 clientId 进行比较。 / p>

I understand that i need to set the clientId and subscription name when writing the jms topic subscriber for my durable topics.

But Whats the purpose of setting the clientID when publishing the TOPIC ? I have seen people setting the client Id even for publisher / consumer, but no one explained that why it is required.

ConnectionFactory conFactory =  this.getConnectionFactory();
Connection connection = conFactory.createConnection();

connection.setClientID("WHATS_MY_PURPOSE"); // Why do we need clientID while publishing the TOPIC from consumer / publisher

connection.start();
MessageProducer producer = session.createProducer(destination);

解决方案

A clientId is required to uniquely identify an application. It's a must when using a durable subscription in Pub/Sub messaging pattern. As you might be aware, a messaging provider caches publications destined for durable subscriber applications when they are off-line. When such applications come on-line again, a messaging provider has to identify OK, this is the same application that created a durable subscription but went away for reason. Now it has come back. So let me deliver all messages that were published when this application was away. To verify it's the same application, messaging provider compares the clientId of the application with clientId available with cached subscription information.

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