Message Queuing Mq-apache ActiveMQ

Apache ACTIVEMQ is an open source messaging middleware developed by the Apache Software Foundation; Since ACTIVEMQ is a pure Jave program, it requires only the operating system to support the Java Virtual machine and ACTIVEMQ can execute it.

1 comparison of technical features between queue and topic

	Topic	Queue
Profile	Publish Subscribe Messaging Publish subscription message	Point-to-Point point-to-point
There is no status	Topic data is not landed by default and is stateless.	Queue data is saved as a file by default on the MQ server, such as Active MQ, which is typically stored under $amq_home\data\kr-store\data. Can also be configured as DB storage.
Integrity Assurance	There is no guarantee that every piece of data published by publisher will be accepted by subscriber.	The queue guarantees that each piece of data can be received by receiver.
Whether the message will be lost	In general, when Publisher publishes a message to a topic, only the sub that is listening to the topic address can receive the message, and if no sub is listening, the topic is lost.	Sender sends a message to the target Queue,receiver can receive the message on this queue asynchronously. Messages on the queue are not lost if they are not currently being picked up by receiver.
Message Publishing Receive Policy	A one-to-many message publishing receive policy that listens to multiple sub-topic addresses to receive messages from Publisher. Sub receives notification MQ server	One message to the receiving policy, a sender sends a message, only one receiver receives. After receiver is received, the MQ server is notified that the MQ server has deleted or otherwise acted on the messages in the queue.

The biggest difference between the topic and the queue is that the topic is in the form of a broadcast that notifies all online listeners that there is a new message, that the client without the listener will not receive the message, and that the queue notifies more than one client in the listening state in the form of a point-to-point.

Message Queuing Mq-apache ActiveMQ