Notification Service 
Purpose
Application name: com.sap.portal.runtime.system.notification
The notification service is responsible for providing support for communication between PRT instances running in different portal environments. The Notification Service has two objectives:
· Deliver an API to send and receive messages between different Web servers. The API is built on the following objects:
¡ INotificationService – the service used to subscribe and receive message
¡ ITopicListener – interface implemented by objects that listen for messages associated to a certain topic
¡ TopicDataContainer – representation of the message sent from one PRT to another PRT
· Maintain the cluster information
The Notification Service understands the cluster configuration. This is the only service that has such knowledge of the execution infrastructure. This implies that a version of the Notification Service should exist for every supported platform. In the SAP J2EE Engine environment, the Notification Service uses the PRT Bridge to manage the communication between the different nodes of the cluster. The PRT Bridge uses the SAP J2EE Engine cluster configuration to obtain such information.
Integration
The following graphic shows the architecture of the Notification Service:
Component B on PRT2 registers to a specific topic and component A publishes a message associated to the topic that component B is interested in. When component A publishes on PRT1, the message is sent to all the PRTs declared in the cluster.
See also: