WAS v8.5 > WebSphere applications > Web services > WS-NotificationWS-Notification: Benefits
WS-Notification enables web services to use the publish and subscribe messaging pattern. This approach offers many business benefits.
WS-Notification provides a standardized approach for web service applications to participate in the publish and subscribe messaging pattern, whether this be listening for notification of a particular event occurrence, or inserting event notifications into the system for consumption by other applications or system management tooling. The open-standards nature of this web services specification mean that applications can communicate with each other irrespective of the underlying hardware platforms, software languages or vendor environments. The WS-Notification implementation in WebSphere Application Server supports the WS-Notification standards, complies with the WS-I Basic Profile 1.0 requirements, and composes with other related standards such as WS-Addressing for High Availability and Workload Management, and WS-ReliableMessaging for reliable communication between components.
Within WAS, the NotificationBroker is implemented to provide flexible support for enterprise topologies including high availability and work load management patterns. This support for WS-Notification also allows interchange of event notification between WS-Notification applications and other clients of the service integration bus. By exploiting other service integration bus functions we can also use this function to interchange messages with other IBM publish and subscribe brokers such as WBI Event Broker or Message Broker.
Rather than receiving all messages on a topic to which we have subscribed, your consuming application can use XML Path (XPath) selectors to filter the messages based upon the contents of each message. This content-based subscription gives you greater flexibility in defining the type of information to receive, and the applications do not need to handle their own filtering. Performance is improved because messages that are not relevant are not sent unnecessarily from the server to the application.
WAS offers two WS-Notification service and service point options:
- v7.0: Use this type of service to compose a JAX-WS WS-Notification service with web service qualities of service (QoS) via policy sets, or to apply JAX-WS handlers to your WS-Notification service. This is the recommended type of service for new deployments. This WS-Notification option has been available in WAS from v7.0.
- v6.1: Use this type of service to expose a JAX-RPC WS-Notification service that uses the same technology provided in WAS v6.1, including the ability to apply JAX-RPC handlers to the service. This WS-Notification option has been available in WAS from v6.1.
The v7.0 WS-Notification option allows you to use web services-based publish/subscribe messaging in a reliable way, through a standards-based connection mechanism, in an environment where network connectivity is not always available. For example, to use the Internet to send warehouse or stock level notifications to remote customers, ensure that messages reach customers reliably so they have accurate stock levels for sales and production planning. We can achieve this by composing JAX-WS based v7.0 WS-Notification services (for stock level notification) with WS-ReliableMessaging (to ensure reliable delivery of notifications).
The main benefits of a v7.0 WS-Notification service over a v6.1 WS-Notification service are as follows:
- It is easier to configure using policy sets.
- It supports JAX-WS handlers.
- It avoids the need to install an SDO repository.
Related concepts:
WS-Notification
Related
Use WS-Notification for publish and subscribe messaging for web services
Secure WS-Notification
Reference:
WS-Notification troubleshooting tips
Events and service-oriented architecture: The OASIS Web Services Notification specifications
OASIS Web Services Notification (WSN) technical committee