Web Services Notification
The Web Services Notification is a specification that enables Web services based subscription and notification messaging. Due to its flexible architecture, it is applicable to almost any domain, including, but not limited to, Grid computing, systems management, integration brokers, and business applications. WS-Notification implements the Notification pattern, where a service provider, or other entity, initiates messages based on a subscription or registration of interest from a service requestor. It defines how the publish/subscribe (pub sub) pattern commonly used in Message-Oriented middleware products can be realized using Web services. This includes brokered as well as direct pub sub which allows the publisher/subscribers to be decoupled and provides greater scalability.