JMS Message Models
Below are the type of message models :
- Point-to-Point (Queues)
- Publish Subscribe (Topics)
- Multicast (Topics)
- Point-to-Point(Queues)
Any number of producers and consumers can exist. At any time and situation each message is taken by only one consumer.
Exclusive: only the first consumer who picks up the first message can take the rest of the messages (used if u wants only one consumer).
Non-exclusive: where any number of consumers can exist. Used for load balancing.
2. Publish-Subscribe(Topics)
Any number of publishers and subscribers can exist. Each message can be taken by any number of consumers (radio type message).
3. Multicast(Topics)
Multicast is a messaging model that allows the EMS server to send messages to multiple consumers simultaneously by broadcasting them over an existing network.
From Version 5.x onwards EMS can use multicast addressing to send messages to topic subscribers. Topic subscribers connect to a Multicast Daemon service which runs on their local machine. The Multicast Daemons are all members of a multicast group. The EMS server transmits topic messages to the multicast group. So that each message is sent by the server only once. Each multicast daemon receives the message and passes it on to its subscribers. This offers considerable efficiencies compared with delivery over direct TCP connections between the subscribers and the server.
- Multicast is available only for topics. There is a property of topic channel.
- Channel property determines the multicast channel over which messages sent to the topic are broadcast.
- Configure multicast channels in channels.conf file and enable this feature in tibemsd.conf
- Cannot create channel by any command in tibemsadmin.
- Only 1 channel allowed for each topic.
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