A quick guide to WS-BaseNotification

Base Notification...
A Web service, or other entity, disseminates information to a set of other Web services, without having to have prior knowledge of these other Web services.


Situation
Something that happens to produce a Notification

Notification
An XML element describing a Situation. Has a namespace qualified Qname and a schema

Subscription
A Web service requester creates a subscription by sending a Subscription request to a NotificationProducer. The requester does not have to be NotificationConsumer.


NotificationProducer:
produces Notification messages.

• Accepts incoming Subscribe requests
• containing a reference to a NotificationConsumer
• identifying Notifications the NotificationProducer should produce (can be described by boolean filters, including filtering by Topic - see [WS-Topics])
• The NotificationProducer agrees to produce Notification Messages or returns a fault
• NotificationProducer, can originate Notifications , or act as a Broker for some other entity (see WS-BrokeredNotification)

Implements the NotificationProducer interface which consists of the following message exchanges:

• Subscribe (ConsumerReference, Filter, InititalTerminationTime, SubscriptionPolicy) - Returns: SubcriptionEndpoint
• GetCurrentMessage (Topic) Returns: any
  

NotificationConsumer
An endpoint (represented by a WS-Addressing endpoint reference) which can receive Notifications.
May implement the generic Notify message exchange, or may implement its own catcher for notifications.

• Notify ( NotificationMessage) - No response
  

SubscriptionManager
An endpoint (represented by a WS-Addressing endpoint reference) that allows a service requester to manipulate Subscriptions. Typically implemented by NotificationProducer
Implements the SubscriptionManager interface which consists of the following message exchanges:

• Renew
• Unsubscribe
• PauseSubscription
• ResumeSubscription
  

PullPoints
It might not be possible for a NotificationProducer to call out to consumers, so BaseNotification defines a PullPoint interface to allow consumers to fetch messages. The Subscriber (or some other entity) can create a PullPoint and then use it as the ConsumerReference in Subscribe a request. The actual consumer then pulls Notifications from the PullPoint

PullPoint interface

• GetMessages
• DestroyPullPoint

Create PullPoint interface

• CreatePullPoint