WS-Notification is a family of related white papers and specifications that define a standard Web services approach to notification using a topic-based publish/subscribe pattern.

The Event-driven, or Notification-based, interaction pattern is a commonly used pattern for inter-object communications. Examples exist in many domains, for example in publish/subscribe systems provided by Message Oriented Middleware vendors, or in system and device management domains. This notification pattern is increasingly being used in a Web services context.

WS-Notification is a family of related white papers and specifications that define a standard Web services approach to notification using a topic-based publish/subscribe pattern. It includes:

• Standard message exchanges to be implemented by service providers that wish to participate in Notifications
• Standard message exchanges for a notification broker service provider (allowing publication of messages from entities that are not themselves service providers)
• Operational requirements expected of service providers and requestors that participate in notifications
• An XML model that describes topics.

Get the specification and related material

You can also get the earlier versions of these specifications by clicking on the following links:

• WS-BaseNotification 1.0 specification. (PDF, March 2004)
• WS-BrokeredNotification 1.0 specification. (PDF, March 2004)
• WS-Topics 1.0 specification. (PDF, March 2004)

The WS-Notification family of documents includes a white paper, "Publish-Subscribe Notification for Web services" (see Resources) as well as three normative specifications: WS-BaseNotification, WS-BrokeredNotification, and WS-Topics.

WS-BaseNotification defines the Web services interfaces for NotificationProducers and NotificationConsumers. It includes standard message exchanges to be implemented by service providers that wish to act in these roles, along with operational requirements expected of them. This is the base specification on which the other WS-Notification specification documents depend. An implementer interested just in direct, point to point, notification need only read this WS-BaseNotification specification, together with the "Publish-Subscribe Notification for Web Services" whitepaper.

WS-BrokeredNotification defines the Web services interface for the NotificationBroker. A NotificationBroker is an intermediary which, among other things, allows publication of messages from entities that are not themselves service providers. It includes standard message exchanges to be implemented by NotificationBroker service providers along with operational requirements expected of service providers and requestors that participate in brokered notifications. This work relies upon WS-BaseNotification and WS-Topics, as well as the "Publish-Subscribe Notification for Web Services" document.

WS-Topics defines a mechanism to organize and categorize items of interest for subscription known as "topics." These are used in conjunction with the notification mechanisms defined in WS-BaseNotification. WS-Topics defines three topic expression dialects that can be used as subscription expressions in subscribe request messages and other parts of the WS-Notification system. It further specifies an XML model for describing metadata associated with topics. This specification should be read in conjunction with the WS-BaseNotification specification and the "Publish-Subscribe Notification for Web Services" document.

Resources

• The whitepaper "Publish-Subscribe Notification for Web services" introduces the concepts of notification patterns and sets the goals and requirements for the WS-Notification family of specifications.
  
  
• The Web Services Resource Framework defines a system for creating stateful resources between Web services in terms of an implied resource pattern.
  
  

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