WAS v8.5 > WebSphere applications > Web services > WS-Notification > WS-Notification: OverviewBase notification
The Web Services Base Notification specification defines WSDL port types for applications that want to act as a NotificationProducer or a NotificationConsumer. A NotificationProducer is an application that inserts event notifications into the system, whereas a NotificationConsumer application receives event notifications that have been published by a different application (usually a NotificationProducer application).
Applications that want to consume event notifications asynchronously must expose a web service endpoint that implements the NotificationConsumer port type (synchronous consumption of event notifications is achieved using a pull point and does not require the application to expose a web service endpoint). The applications then locate the NotificationProducer (or NotificationBroker) application that produces the event notifications they want to receive and invoke the Subscribe operation on that NotificationProducer application. The Subscribe operation has several parameters that allow the consuming application to indicate which type of notifications it is interested in (for example using the topic of the notification). One of the required parameters of the Subscribe operation is the ConsumerReference parameter, where the consuming application indicates the endpoint against which the Notify operation can be invoked when matching event notifications are generated by the NotificationProducer application.
The NotificationProducer application is responsible for the following tasks in relation to its production of event notifications:
- It accepts the Subscribe operation to allow NotificationConsumer applications to register their interest.
- It maintains the list of active subscriptions it has accepted.
- It generates event notification messages.
- It matches generated event notifications against the active subscriptions.
- It distributes event notifications to NotificationConsumer applications with subscriptions that match the notification.
A NotificationProducer application works cooperatively with a SubscriptionManager service to handle the lifecycle of a Subscription, allowing both scheduled (that is terminationTime) and immediate destruction and deletion of the Subscription.
For an introduction to basic web services terminology such as port type, see Deploy web services with WSDL: Part 1.
Related concepts:
Brokered notification
WS-Topics
WS-Notification
Related
Use WS-Notification for publish and subscribe messaging for web services
Secure WS-Notification
Reference:
WS-Notification troubleshooting tips
WS-BaseNotification v1.3 OASIS Standard
XML Path Language (XPath) v1.0
XQuery 1.0 and XPath 2.0 Formal Semantics