【转】Difference between Point-To-Point and Publish/Subscribe JMS Messaging Models

Difference between Point-To-Point and Publish/Subscribe JMS Messaging Models

 

Point-to-Point (PTP) and Publish/Subscribe (Pub/Sub) are two types of messaging models or messaging domains provided by JMS. Both of these have significant differences and should be used as per the application’s requirement. For instance, point-to-point messaging should be used when each message delivered by a producer should be consumed successfully by one receiver andpublish/subscribe messaging should be used when each message delivered by a producer should be consumed by zero or more receivers.

Here is a more detailed difference between the two messaging models:

	Point-to-Point (Queue)	Publish-Subscribe (Topic)
1.	Each message is addressed to a virtual channel known as Queue	Each message is addressed to a virtual channel know as Topic
2.	One-to-One i.e. a message delivered by a producer is consumed by only one receiver	One-to-Many i.e. a message delivered by a producer (publisher) can be consumed by zero or more receivers (subscribers)
3.	A queue can have multiple receivers, but each message is consumed by only one receiver	A topic can have multiple receivers and every receiver receives a copy of each message
4.	Pull-based model i.e. client polls the queue for new messages and sends the request	Push-based model i.e. messages are broadcasted to all the subscribers without them having to poll the topic
5.	Messages are retained in the queue until they are delivered to the receiver. The receiver can fetch the message even if it was not running when producer sent the messages.	Messages are retained in the topic until they are delivered to the “current“ subscribers.There is an option to have durable subscriptions in pub-sub model which allows the subscriber to dis-connect, reconnect again and collect the messages that were delivered when it was not active.
6.	The receiver acknowledges the successful processing of a message.	Acknowledgment is optional.

Thus whether to use queue or topic as JMS message destination, depends solely on the requirements of a specific application.

转自： http://verticalhorizons.in/difference-between-point-to-point-and-publishsubscribe-jms-messaging-models/