CONNECT EVERYTHING. ACHIEVE ANYTHING. ™ WS-Brokered Notification Dave Chappell Sonic Software

2© 2004 Sonic Software Corporation Similar roles as in direct, adding ‘Broker’ Role –Broker (intermediary) permits decoupling Publisher and Subscriber Subscriber indicates interest in a particular “Topic” by issuing a “subscribe” request “Subscriptions” are WS-Resources –Various subscriptions are possible Broker responsible for disseminating notifications – examines current subscriptions for match Brokers may provide “value add” –“Transform” or “interpret” topics –Federate to provide scalability Broker Subscriber WS-Notification: Brokered Notification Publisher subscribe SS S notify

3© 2004 Sonic Software Corporation WS-BrokeredNotification A Broker is an intermediary between publisher and consumer (implements both Producer and Consumer) –Manages subscriptions on behalf of the publisher –Delivers notifications to consumers –Can provide additional added value (e.g. subscription transformation) Rationale –Scalability and separation of concerns –Reduces the number of interconnects –Point to administer and control subscriptions –Subscribers do not need to discover individual publishers –Can hide the identity of the publisher –Represents a messaging infrastructure

4© 2004 Sonic Software Corporation Publishing Patterns Simple Publisher –need NOT be a Web Service (Web Service client) Web service implements NotificationProducer –Accepts subscriptions from the broker Demand-based publishing –Observing behavior might be expensive –Publishing messages might be expensive –Pause/Resume publishing If nobody is subscribed, don’t send it

5© 2004 Sonic Software Corporation NotificationBroker interface Must support the following WS-ResourceProperties –RequiresRegistration (xsd:boolean) –Resource Properties from NotificationProducer Topics FixedTopicSet (xsd:boolean) TopicExpressionDialects (ConcreteTopicPath, FullTopicPath DavesAmazingTopicPath, etc.) Subscribe (from NotificationProducer Interface) –Must support hierarchical topics, and the ConcreteTopicPath topic expression dialect Explicit Notify (from NotificationConsumer Interface) RegisterPublisher –Allows publishers to pre-register with the broker –Demand-based publishing

6© 2004 Sonic Software Corporation PublisherRegistrationManager Used to track/control the registrations of publishers with the NotificationBroker Very similar to SubscriptionManager –Implicit resource pattern –Properties of registrations returned using WS-RP E.g. PublisherRef, Topic, CreationTime –Lifetime of registrations using WS-Lifetime

7© 2004 Sonic Software Corporation WS-Base Notification Warehouse Application Service Subsidiary Service Application Sales Application Service Partners Service Application Finance Application Service

8© 2004 Sonic Software Corporation Publisher(s) Application Service Subscriber(s) WS-BrokeredNotification Service Broker

9© 2004 Sonic Software Corporation Regional Offices Headquarters Business Partner Acquired Co. Warehouse Application Service Application Service Application WS-BrokeredNotification Broker