WS notification

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WS-Notification is a collection of specifications from the so-called WS- * -Framework to support event-driven programming ( "event driven programming"). It uses a publish / suscribe pattern based on WS-Topic . This defines

  • Interfaces that have to be implemented by service providers
  • Interfaces that have to be implemented by service brokers (who are not providers themselves)
  • an XML data format to define topics
  • Requirements for service providers and users.

WS-Notification supports both peer-to-peer connections and broker-based publish / suscribe systems.

Sub-specifications

WS-Notification includes several sub-specifications:

WS-Base Notification

Principle of WS-Base Notification

WS-Base Notification distinguishes between message producers and consumers ( notification producer and notification consumer ). A message generator is a service that does the actual notification. For this purpose, it offers an external interface that accepts subscribe requests . A message consumer receives the notifications . For this purpose, this service offers an external notify interface. In addition, there is (often combined with the message producer) a source for messages. According to certain criteria, the message generator then selects those consumers for whom this information is relevant and calls up the corresponding notify services. One also speaks of peer-to-peer notification .

WS-Brokered Notification

Principle of WS-Brokered Notification

With WS-Brokered Notification an attempt is made to separate these participants even further. In addition to the service that publishes a message, the recipient of the notification and the person who is actually interested in the message, another participant, the so-called notification broker, is introduced. This is at the same time the message producer and consumer in the sense of WS-Base Notification , in that he is notified by the publisher who publishes the message and then in turn notifies all message consumers who are registered with him, so that the actual interested parties can pick up their message can. This is why this system is also known as Brokered Notification .

WS topics

WS-Topics offers mechanisms for categorizing topics and dividing them into blocks. An interested party in news can then define a list of topics that are relevant to him, which the message producer (the creator of the notification) then compares against incoming messages and their topics.

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